chore: prepare release v1.1.0

.forgejo/workflows/test.yml

@@ -1,47 +0,0 @@
-name: Test
-
-on:
-  push:
-    branches: [development]
-  pull_request:
-    branches: [development]
-
-jobs:
-  vet:
-    runs-on: codeberg-small
-    steps:
-      - uses: https://data.forgejo.org/actions/checkout@v4
-
-      - uses: https://data.forgejo.org/actions/setup-go@v5
-        with:
-          go-version: "1.26"
-
-      - name: Download dependencies
-        run: go mod download
-
-      - name: gofmt
-        # `gofmt -l` prints the names of unformatted files. An empty
-        # output is the only acceptable result.
-        run: gofmt -l cmd internal pkg
-
-      - name: go vet
-        run: go vet ./...
-
-  test:
-    runs-on: codeberg-small
-    needs: vet
-    steps:
-      - uses: https://data.forgejo.org/actions/checkout@v4
-
-      - uses: https://data.forgejo.org/actions/setup-go@v5
-        with:
-          go-version: "1.26"
-
-      - name: Download dependencies
-        run: go mod download
-
-      - name: go test -race
-        run: go test -race -count=1 ./...
-
-      - name: go test ./examples
-        run: go build ./examples/...

.gitea/workflows/release.yml

@@ -2,11 +2,11 @@ name: Release
 
 on:
   push:
-    tags: ["v*"]
+    tags: ["v*.*.*"]
 
 jobs:
   build:
-    runs-on: codeberg-small
+    runs-on: fedora
     strategy:
       fail-fast: false
       matrix:
@@ -15,14 +15,20 @@ jobs:
             goarch: amd64
           - goos: linux
             goarch: arm64
+          - goos: linux
+            goarch: riscv64
+          - goos: linux
+            goarch: loong64
           - goos: freebsd
             goarch: amd64
           - goos: freebsd
             goarch: arm64
+          - goos: freebsd
+            goarch: riscv64
     steps:
-      - uses: https://data.forgejo.org/actions/checkout@v4
+      - uses: actions/checkout@v4
 
-      - uses: https://data.forgejo.org/actions/setup-go@v5
+      - uses: actions/setup-go@v5
         with:
           go-version: "1.26"
 
@@ -32,7 +38,7 @@ jobs:
       - name: Build
         id: build
         env:
-          REF: ${{ forgejo.ref }}
+          REF: ${{ gitea.ref }}
 
         run: |
           set -euo pipefail
@@ -45,36 +51,41 @@ jobs:
           fi
 
           VERSION_NO_V="${VERSION#v}"
-          echo "version_no_v=${VERSION_NO_V}" >> "$FORGEJO_OUTPUT"
+          echo "version_no_v=${VERSION_NO_V}" >> "$GITEA_OUTPUT"
 
-          LDFLAGS="-s -w -X codeberg.org/petrbalvin/nuntius/internal/version.Version=${VERSION}"
+          LDFLAGS="-s -w -X sourcedock.dev/petrbalvin/nuntius/internal/version.Version=${VERSION_NO_V}"
           mkdir -p bin
-          GOOS=${{ matrix.goos }} GOARCH=${{ matrix.goarch }} \
+          GOOS=${{ matrix.goos }} GOARCH=${{ matrix.goarch }} CGO_ENABLED=0 \
             go build -ldflags "$LDFLAGS" \
               -o "bin/nuntius-${VERSION_NO_V}-${{ matrix.goos }}-${{ matrix.goarch }}" \
               ./cmd/server
 
       - name: Upload artifact
-        uses: https://data.forgejo.org/actions/upload-artifact@v3
+        uses: actions/upload-artifact@v3
         with:
           name: nuntius-${{ matrix.goos }}-${{ matrix.goarch }}
           path: bin/nuntius-${{ steps.build.outputs.version_no_v }}-${{ matrix.goos }}-${{ matrix.goarch }}
           if-no-files-found: error
 
+      - name: Smoke test
+        run: |
+          chmod +x bin/nuntius-${{ steps.build.outputs.version_no_v }}-${{ matrix.goos }}-${{ matrix.goarch }}
+          ./bin/nuntius-${{ steps.build.outputs.version_no_v }}-${{ matrix.goos }}-${{ matrix.goarch }} --version
+
   release:
-    runs-on: codeberg-tiny
+    runs-on: fedora
     needs: build
     steps:
-      - uses: https://data.forgejo.org/actions/checkout@v4
+      - uses: actions/checkout@v4
 
       - name: Download all artifacts
-        uses: https://data.forgejo.org/actions/download-artifact@v3
+        uses: actions/download-artifact@v3
         with:
           path: dist
 
       - name: Extract CHANGELOG section
         env:
-          VERSION: ${{ forgejo.ref_name }}
+          VERSION: ${{ gitea.ref_name }}
         run: |
           set -euo pipefail
           VERSION_NO_V="${VERSION#v}"
@@ -96,7 +107,7 @@ jobs:
 
       - name: Create release
         env:
-          FORGEJO_TOKEN: ${{ secrets.FORGEJO_TOKEN }}
+          GITEA_TOKEN: ${{ secrets.GITEA_TOKEN }}
         run: |
           set -euo pipefail
           # JSON-escape the release body with sed: backslashes first, then
@@ -111,13 +122,13 @@ jobs:
           BODY="\"${BODY}\""
 
           response=$(curl -sS -w '\n%{http_code}' \
-            -H "Authorization: token ${FORGEJO_TOKEN}" \
+            -H "Authorization: token ${GITEA_TOKEN}" \
             -H "Content-Type: application/json" \
             -X POST \
-            "${FORGEJO_SERVER_URL}/api/v1/repos/${FORGEJO_REPOSITORY}/releases" \
+            "${GITEA_SERVER_URL}/api/v1/repos/${GITEA_REPOSITORY}/releases" \
             -d "{
-              \"tag_name\": \"${FORGEJO_REF_NAME}\",
+              \"tag_name\": \"${GITEA_REF_NAME}\",
-              \"name\": \"${FORGEJO_REF_NAME}\",
+              \"name\": \"${GITEA_REF_NAME}\",
               \"body\": ${BODY},
               \"draft\": false,
               \"prerelease\": false
@@ -139,7 +150,7 @@ jobs:
 
       - name: Upload assets
         env:
-          FORGEJO_TOKEN: ${{ secrets.FORGEJO_TOKEN }}
+          GITEA_TOKEN: ${{ secrets.GITEA_TOKEN }}
         run: |
           set -euo pipefail
           RELEASE_ID=$(cat release-id.txt)
@@ -150,11 +161,11 @@ jobs:
             fname=$(basename "$binary")
             echo "Uploading ${fname}..."
             http_code=$(curl -sS -o /dev/null -w '%{http_code}' \
-              -H "Authorization: token ${FORGEJO_TOKEN}" \
+              -H "Authorization: token ${GITEA_TOKEN}" \
               -H "Content-Type: application/octet-stream" \
               -X POST \
               --data-binary "@${binary}" \
-              "${FORGEJO_SERVER_URL}/api/v1/repos/${FORGEJO_REPOSITORY}/releases/${RELEASE_ID}/assets?name=${fname}")
+              "${GITEA_SERVER_URL}/api/v1/repos/${GITEA_REPOSITORY}/releases/${RELEASE_ID}/assets?name=${fname}")
             echo "  HTTP ${http_code}"
             if [ "$http_code" != "201" ]; then
               echo "Failed to upload ${fname}"
@@ -163,5 +174,5 @@ jobs:
           done
 
           echo
-          echo "Release ${FORGEJO_REF_NAME} is live with the following assets:"
+          echo "Release ${GITEA_REF_NAME} is live with the following assets:"
           ls -lh dist/nuntius-*/

.gitea/workflows/test.yml

@@ -0,0 +1,83 @@
+name: Test
+
+on:
+  push:
+    branches: [development]
+  pull_request:
+    branches: [development]
+
+jobs:
+  vet:
+    runs-on: fedora
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version: "1.26"
+
+      - name: Download dependencies
+        run: go mod download
+
+      - name: gofmt
+        # `gofmt -l` prints the names of unformatted files. An empty
+        # output is the only acceptable result.
+        run: |
+          unformatted=$(gofmt -l cmd internal pkg)
+          if [ -n "$unformatted" ]; then
+            echo "The following files need gofmt:"
+            echo "$unformatted"
+            exit 1
+          fi
+
+      - name: go vet
+        run: go vet ./...
+
+  test:
+    runs-on: fedora
+    needs: vet
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version: "1.26"
+
+      - name: Download dependencies
+        run: go mod download
+
+      - name: Install build tools
+        run: dnf install -y gcc
+
+      - name: go test -race
+        run: go test -race -count=1 ./...
+
+      - name: Check coverage threshold
+        run: |
+          go test -coverprofile=coverage.out ./internal/... ./pkg/...
+          go tool cover -func=coverage.out | grep '^total:' | python3 -c "import sys; pct=float(sys.stdin.read().split()[2].rstrip('%')); sys.exit(0 if pct >= 80 else 1)" || (echo "ERROR: coverage < 80%"; exit 1)
+
+      - name: go test ./examples
+        run: go build ./examples/...
+
+  build:
+    runs-on: fedora
+    needs: test
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version: "1.26"
+
+      - name: Download dependencies
+        run: go mod download
+
+      - name: Build
+        run: go build -ldflags="-s -w" -o bin/nuntius ./cmd/server
+
+      - name: Test
+        run: go test ./...
+
+      - name: Smoke test
+        run: ./bin/nuntius --version

.gitignore

@@ -2,6 +2,7 @@
 bin/
 *.test
 *.out
+__pycache__/
 
 # Local secrets and config
 .env*

CHANGELOG.md

@@ -5,13 +5,57 @@ All notable changes to **nuntius** are documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [development]
+
+## [1.1.0] — 2026-07-26
+
+### Added
+
+- **RISC-V and LoongArch builds** — CI now produces binaries for `linux/riscv64`,
+  `linux/loong64`, and `freebsd/riscv64` in addition to the existing four
+  targets.
+- **80 % coverage gate** — `just test` and CI enforce ≥ 80 % test coverage on
+  `internal/` and `pkg/` packages.
+- **Handler and email test suites** — 22 handler tests covering CORS, rate
+  limiting, validation, honeypot, and send/store paths via mock interfaces.
+  12 email composition tests covering all four form types.
+
+### Changed
+
+- **Module migrated to sourcedock.dev** — all imports and documentation now
+  reference `sourcedock.dev/petrbalvin/nuntius`.
+- **CI migrated from Forgejo to Gitea** — workflows now live in
+  `.gitea/workflows/`, run on the `fedora` runner, and use the standard
+  `actions/*` short form.
+- **Dependency bump** — `interpres` updated to v1.1.1.
+- **IPv6-first** — the server now binds `[::]:port` for explicit dual-stack.
+- **Installer rewritten in Python** — `install.py` replaces `install.sh`.
+- **nginx → Caddy** — all documentation and the installer now use Caddy as the
+  recommended reverse proxy.
+
+### Fixed
+
+- **Rate limiter memory leak** — a periodic cleanup goroutine removes expired
+  IP entries from the token-bucket map.
+- **Silent template errors** — `compose()` now produces a fallback HTML message
+  instead of silently discarding template execution errors.
+- **Silent JSON encoding errors** — all `json.NewEncoder(w).Encode()` calls now
+  log errors instead of discarding them.
+- **CI formatting gate** — `gofmt -l` in the test workflow now actually fails
+  when it finds unformatted files.
+- **Missing `just fmt` recipe** — added `gofmt -w` target.
+- **Copyright headers** — added to all Go and Python source files.
+
+[development]: https://sourcedock.dev/petrbalvin/nuntius/compare/v1.1.0...development
+[1.1.0]: https://sourcedock.dev/petrbalvin/nuntius/releases/tag/v1.1.0
+
 ## [1.0.0] — 2026-06-20
 
 First stable release of nuntius: a small, opinionated, modular contact form
 backend written in Go. A single static binary, four form kinds out of the box,
 SMTP delivery, a JSONL newsletter log, strict TOML configuration, and env-var
 secrets. Its only dependency outside the standard library is the first-party
-[interpres](https://codeberg.org/petrbalvin/interpres) TOML parser.
+[interpres](https://sourcedock.dev/petrbalvin/interpres)
 
 ### Added
 
@@ -44,9 +88,11 @@ secrets. Its only dependency outside the standard library is the first-party
   `/etc/nuntius/config.toml` on first start.
 - **systemd unit** — installed inline from `docs/deployment.md` with
   `Restart=on-failure` and `EnvironmentFile=`.
-- **Install script** — `install.sh`, idempotent, handles user creation, config
+- **Install script** — `install.py`, idempotent, handles user creation, config
   generation, and secrets file mode `0600`.
 - **docs/** — `architecture.md`, `configuration.md`, `api-reference.md`,
   `deployment.md`, `security.md`, `library-usage.md`.
 
-[1.0.0]: https://codeberg.org/petrbalvin/nuntius/releases/tag/v1.0.0
+[1.1.0]: https://sourcedock.dev/petrbalvin/nuntius/releases/tag/v1.1.0
+
+[1.0.0]: https://sourcedock.dev/petrbalvin/nuntius/releases/tag/v1.0.0

CONTRIBUTING.md

@@ -18,13 +18,13 @@ See [Cutting a release](#cutting-a-release) for the full procedure.
 
 - **Go 1.26+** (uses Go 1.22+ `http.ServeMux` method patterns and `log/slog`)
 - [`just`](https://github.com/casey/just) command runner (the `justfile` is the source of truth for build / test / run / install / uninstall)
-- Linux, macOS, or FreeBSD
+- Linux or FreeBSD
 - A local SMTP account for end-to-end testing. Tests in `internal/storage` and `pkg/contactform` do not require SMTP.
 
 ### Quick Start
 
 ```bash
-git clone https://codeberg.org/petrbalvin/nuntius.git
+git clone https://sourcedock.dev/petrbalvin/nuntius.git
 cd nuntius
 just install        # go mod tidy + go mod download (no third-party modules — no-op for this project)
 just build          # → ./bin/nuntius (with -ldflags="-s -w")
@@ -42,8 +42,15 @@ just test
 
 The suite covers:
 
-- `pkg/contactform` — validators for all four form types (contact, feedback, newsletter, generic), whitespace trimming, and error message shape.
+- `cmd/server` — client IP extraction, request-logging middleware.
+- `internal/config` — TOML loading, env-var expansion, schema validation.
+- `internal/email` — SMTP message composition (`multipart/alternative`) and subject templates.
+- `internal/handler` — form handler pipeline (CORS, rate limit, honeypot, validation, send), rate-limiter cleanup loop.
 - `internal/storage` — `Append` / `Count` / `List` semantics, file and directory auto-creation, missing-file tolerance, malformed-line resilience.
+- `internal/version` — version identity and `--version` smoke output.
+- `pkg/contactform` — validators for all four form types (contact, feedback, newsletter, generic), whitespace trimming, and error message shape.
+
+CI enforces a **≥80 % coverage threshold** on `internal/...` and `pkg/...`. Run `go test -coverprofile=coverage.out ./internal/... ./pkg/... && go tool cover -func=coverage.out` locally to check before pushing.
 
 ### Linting
 
@@ -140,7 +147,7 @@ nuntius/
 ├── examples/
 │   └── minimal/        # Standalone usage of pkg/contactform (no HTTP server)
 ├── docs/               # Architecture, configuration, API, deployment, security, library usage
-├── install.sh          # One-shot server installer (idempotent)
+├── install.py          # One-shot server installer (idempotent)
 ├── justfile            # install, build, test, run, uninstall
 ├── go.mod              # Go 1.26, no external dependencies
 └── LICENSE             # MIT
@@ -151,7 +158,7 @@ nuntius/
 ```mermaid
 graph TD
     Browser[Browser / Frontend]:::accent6
-    Nginx[nginx reverse proxy]:::accent6
+    Caddy[Caddy reverse proxy]:::accent6
     CLI[cmd/server/main.go]:::accent0
     Config[internal/config/]:::accent7
     Handler[internal/handler/]:::accent0
@@ -161,8 +168,8 @@ graph TD
     SMTP[(SMTP server)]:::accent2
     JSONL[(data_dir/newsletter-*.jsonl)]:::accent2
 
-    Browser -->|POST /api/nuntius/contact| Nginx
+    Browser -->|POST /api/nuntius/contact| Caddy
-    Nginx -->|forward with X-Forwarded-For| CLI
+    Caddy -->|forward with X-Forwarded-For| CLI
     CLI --> Config
     CLI --> Handler
     Handler --> Validate
@@ -170,8 +177,8 @@ graph TD
     Handler --> Storage
     Email -->|SMTP PLAIN| SMTP
     Storage -->|append JSONL| JSONL
-    Handler -->|200 ok / 4xx / 5xx| Nginx
+    Handler -->|200 ok / 4xx / 5xx| Caddy
-    Nginx --> Browser
+    Caddy --> Browser
 
     classDef accent0 fill:#3B82F6,stroke:#2563EB,color:#fff
     classDef accent1 fill:#22C55E,stroke:#16A34A,color:#fff
@@ -203,16 +210,16 @@ graph TD
 
 ## CI
 
-This project uses **Forgejo Actions** for continuous integration. The two workflow files live under `.forgejo/workflows/` and are the source of truth for what runs on every push and on every tagged release.
+This project uses **Gitea Actions** for continuous integration. The two workflow files live under `.gitea/workflows/` and are the source of truth for what runs on every push and on every tagged release.
 
-### Test workflow — `.forgejo/workflows/test.yml`
+### Test workflow — `.gitea/workflows/test.yml`
 
-Triggered on every push to `development` and on every pull request targeting `development`. `main` is excluded on purpose — it only ever receives release tags, and the release workflow builds the binaries itself. Three jobs run in sequence, all on the `codeberg-small` runner:
+Triggered on every push to `development` and on every pull request targeting `development`. `main` is excluded on purpose — it only ever receives release tags, and the release workflow builds the binaries itself. Three jobs run in sequence, all on the `fedora` runner:
 
 | Job | What it does | Why it exists |
 |---|---|---|
 | `vet` | `gofmt -l cmd internal pkg` (must print nothing) and `go vet ./...` | Catches formatting drift and static-analysis issues before tests run. |
-| `test` | `go test -race -count=1 ./...` plus `go build ./examples/...` | Race detector catches issues in the per-form rate limiter, the storage mutex, and the SMTP send path. `-count=1` disables the result cache. The example build is a smoke test for the public library. |
+| `test` | `go test -race -count=1 ./...`, coverage gate (`≥80 %` on `internal/...` and `pkg/...`), plus `go build ./examples/...` | Race detector catches issues in the per-form rate limiter, the storage mutex, and the SMTP send path. `-count=1` disables the result cache. The coverage gate fails the build if the combined statement coverage drops below 80 %. The example build is a smoke test for the public library. |
 | `build` | `just build`, `just test`, and `./bin/nuntius --version` smoke test | Confirms the `justfile` build recipe works end-to-end and that `--version` still prints the expected output. |
 
 Run the same checks locally before opening a pull request:
@@ -225,32 +232,32 @@ just build
 ./bin/nuntius --version     # sanity-check the new flag
 ```
 
-### Release workflow — `.forgejo/workflows/release.yml`
+### Release workflow — `.gitea/workflows/release.yml`
 
 Triggered by pushing a tag that matches `v*.*.*` (e.g. `v1.0.0`, `v1.2.3`) onto `main`. The merge from `development` into `main` is the maintainer's responsibility and happens before the tag is pushed — this workflow does not merge anything. Two jobs:
 
-1. **`build`** — Runs on a `codeberg-small` runner in a 4-way matrix: `linux/amd64`, `linux/arm64`, `freebsd/amd64`, `freebsd/arm64`. The default `actions/checkout@v4` checks out the tagged commit (the trigger was a tag push), which is exactly the commit on `main` we want to ship. The version is baked in via `-ldflags`:
+1. **`build`** — Runs on a `fedora` runner in a 7-way matrix: `linux/amd64`, `linux/arm64`, `linux/riscv64`, `linux/loong64`, `freebsd/amd64`, `freebsd/arm64`, `freebsd/riscv64`. The default `actions/checkout@v4` checks out the tagged commit (the trigger was a tag push), which is exactly the commit on `main` we want to ship. The version is baked in via `-ldflags`:
    ```bash
-   -X codeberg.org/petrbalvin/nuntius/internal/version.Version=${VERSION#v}
+   -X sourcedock.dev/petrbalvin/nuntius/internal/version.Version=${VERSION_NO_V}
    ```
    The resulting binary is uploaded as a workflow artifact and smoke-tested with `--version` on the build host.
-2. **`release`** — Runs on a `codeberg-tiny` runner (no Go toolchain needed). Downloads all artifacts, extracts the matching section from `CHANGELOG.md` for the tagged version, creates a release via the Forgejo REST API, and uploads each binary as a release asset. The release is **non-draft, non-prerelease**; if the CHANGELOG section is missing, the job fails fast so a release cannot ship without notes.
+2. **`release`** — Runs on a `fedora` runner (no Go toolchain needed). Downloads all artifacts, extracts the matching section from `CHANGELOG.md` for the tagged version, creates a release via the Gitea REST API, and uploads each binary as a release asset. The release is **non-draft, non-prerelease**; if the CHANGELOG section is missing, the job fails fast so a release cannot ship without notes.
 
 ### Cutting a release
 
 1. Bump `Version` in `internal/version/version.go`.
 2. Add a new `## [X.Y.Z] — YYYY-MM-DD` section at the top of `CHANGELOG.md`.
 3. Make sure CI is green on `development` (pushes and PRs against `development` are what the test workflow runs on).
-4. Merge `development` into `main` (e.g. open a PR on Forgejo, or `git checkout main && git merge --no-ff development && git push origin main`). This is the **only** step where `main` is updated outside of a tag push.
+4. Merge `development` into `main` (e.g. open a PR on Gitea, or `git checkout main && git merge --no-ff development && git push origin main`). This is the **only** step where `main` is updated outside of a tag push.
 5. Tag the `main` tip and push the tag:
    ```bash
    git tag -a vX.Y.Z -m "nuntius vX.Y.Z"
    git push origin main
    git push origin vX.Y.Z
    ```
-6. The release workflow builds the four platform binaries and creates the release with the CHANGELOG section as the body. No CI step performs the merge — that already happened in step 4.
+6. The release workflow builds the seven platform binaries and creates the release with the CHANGELOG section as the body. No CI step performs the merge — that already happened in step 4.
 
-If the release job fails, the tag can be deleted and re-pushed; the workflow re-runs on the new tag push. Do not re-tag an already-released commit — the Forgejo API rejects duplicate release tag names.
+If the release job fails, the tag can be deleted and re-pushed; the workflow re-runs on the new tag push. Do not re-tag an already-released commit — the Gitea API rejects duplicate release tag names.
 
 ## Adding a New Form Type
 
@@ -264,7 +271,7 @@ The four current types (`contact`, `feedback`, `newsletter`, `generic`) live in
 
 ## Report a Bug
 
-Open an issue at <https://codeberg.org/petrbalvin/nuntius/issues> with:
+Open an issue at <https://sourcedock.dev/petrbalvin/nuntius/issues> with:
 
 - nuntius version (`./bin/nuntius --version`).
 - Operating system and architecture.

README.md

@@ -1,145 +1,83 @@
 # Nuntius — A Small, Opinionated Contact Form Backend
 
-[![License](https://img.shields.io/badge/license-MIT-brightgreen)](LICENSE)
-[![Go](https://img.shields.io/badge/Go-00ADD8?labelColor=00ADD8&logo=go&logoColor=fff)](https://go.dev)
-[![Linux](https://img.shields.io/badge/Linux-FCC624?logo=linux&logoColor=000)](https://kernel.org)
-[![FreeBSD](https://img.shields.io/badge/FreeBSD-AB2B28?logo=freebsd&logoColor=fff)](https://freebsd.org)
-
 > Latin *nuntius* = "messenger" — the service that carries messages from visitors to you.
 
-**nuntius** is a small, modular contact form backend written in Go. It serves multiple JSON endpoints (contact, feedback, newsletter, generic) over a single static binary, delivers submissions via SMTP, optionally persists newsletter signups to a JSONL log, and is designed to sit behind nginx on a tiny Linux server. Only the first-party `interpres` TOML module, no external third-party Go modules, ~6 MB binary.
+**nuntius** is a small, modular contact form backend written in Go. It serves multiple
+JSON endpoints (contact, feedback, newsletter, generic) over a single static binary,
+delivers submissions via SMTP, optionally persists newsletter signups to a JSONL log,
+and is designed to sit behind Caddy on a modest Linux or FreeBSD server.
 
-## Features
+Module `sourcedock.dev/petrbalvin/nuntius` — Go 1.26, zero third-party dependencies.
-
+The only external module is the first-party
-- **Single static binary** — `go build -ldflags="-s -w"` produces ≈ 6 MB; no Node, no Python, no Redis, no Postgres, no third-party Go packages.
+[`interpres`](https://sourcedock.dev/petrbalvin/interpres) TOML parser. Stripped
-- **Four form kinds out of the box** — `contact`, `feedback`, `newsletter`, and `generic`. Each gets its own endpoint, rate limit, CORS allowlist, and honeypot field.
+binary is roughly 6 MB.
-- **SMTP delivery** — Go stdlib `net/smtp` with `PLAIN` auth. Works with any provider that exposes SMTP.
-- **Newsletter subscribers on disk** — append-only JSONL log under `data_dir/`. No database, no double opt-in. One `{email, ip, form, created_at}` line per signup.
-- **Server-side validation** — `pkg/contactform.Validate` is reusable; name, email (RFC 5322), service allow-list (for `contact`), and message length.
-- **Reusable package** — `pkg/contactform` exports typed `Request` / `Response` / `ErrorResponse` plus a `Validate` function you can drop into any Go project.
-- **Structured logging** — `log/slog` with JSON output to stdout; plays well with journald, Loki, Datadog…
-- **Graceful shutdown** — SIGINT/SIGTERM close in-flight requests within 15 s.
-- **Rate limiting** — token-bucket per IP, configurable per hour, in-memory (no Redis required).
-- **Honeypot field** — invisible to humans, required for spam bots. Silently accepts and drops.
-- **Config validation** — unknown fields and unknown form types are rejected at startup, so typos fail loudly instead of silently disabling a form.
-- **Env-var secrets** — `${VAR_NAME}` / `$VAR_NAME` expansion in the TOML file keeps SMTP passwords out of disk.
 
 ## Quick Start
 
 ```bash
 # 1. Clone
-git clone https://codeberg.org/petrbalvin/nuntius.git
+git clone https://sourcedock.dev/petrbalvin/nuntius.git
 cd nuntius
 
 # 2. Build
 just build
 # → ./bin/nuntius
 
-# 3. Run (auto-creates /etc/nuntius/config.toml with a 3-form template on first start)
+# 3. Run (writes a three-form config template to /etc/nuntius/config.toml on first start)
 sudo mkdir -p /etc/nuntius
 just run
-# → "nuntius starting" addr=:8080 forms=3
+# → nuntius starting  addr=[::]:8080  forms=3
 
-# 4. Edit the generated config to point at your SMTP and recipient
+# 4. Edit the generated config with your SMTP credentials and recipient address
 sudo $EDITOR /etc/nuntius/config.toml
 just run   # restart to pick up changes
 ```
 
-A default `config.toml` is auto-generated at `/etc/nuntius/config.toml` on first run with three sample forms (contact, feedback, newsletter). Edit it before exposing the service.
+A default `config.toml` is auto-generated at `/etc/nuntius/config.toml` on first
+run with three sample forms (contact, feedback, newsletter). Edit it before
+exposing the service to the internet.
 
-The full schema lives in [`docs/configuration.md`](docs/configuration.md); the deploy guide is in [`docs/deployment.md`](docs/deployment.md).
+The full schema lives in [`docs/configuration.md`](docs/configuration.md); the
+production deploy guide is in [`docs/deployment.md`](docs/deployment.md).
 
-## Usage
+## Features
 
-### Test the endpoints
+- **Single static binary** — `go build -ldflags="-s -w"` produces roughly 6 MB;
+  no Node, no Python, no Redis, no Postgres, no third-party Go packages.
+- **Four form kinds** — `contact`, `feedback`, `newsletter`, and `generic`. Each
+  gets its own endpoint, rate limit, CORS allowlist, and honeypot field.
+- **SMTP delivery** — Go stdlib `net/smtp` with `PLAIN` auth over STARTTLS or
+  implicit TLS. Works with any standards-compliant SMTP provider.
+- **Newsletter subscribers on disk** — append-only JSONL log under `data_dir/`.
+  No database, no double opt-in. One `{email, ip, form, created_at}` line per
+  valid signup.
+- **Server-side validation** — `pkg/contactform.Validate` is reusable; validates
+  name, email (RFC 5322), service allow-list (for `contact`), and message length.
+- **Reusable Go package** — `pkg/contactform` exports typed `Request`, `Response`,
+  and `ErrorResponse` structs plus the `Validate` function you can import into
+  any Go project.
+- **Structured logging** — `log/slog` with JSON output to stdout; plays well
+  with journald, Loki, Datadog, and similar.
+- **Graceful shutdown** — SIGINT and SIGTERM close in-flight requests within a
+  configurable deadline (default 15 s).
+- **Token-bucket rate limiting** — per IP, per form, configurable submissions per
+  hour; in-memory, no external store required.
+- **Honeypot field** — invisible to humans, required by bots. Silently accepts
+  and drops spam submissions.
+- **TOML configuration** — single file, parsed by the first-party `interpres`
+  library. Unknown fields and unknown form types are rejected at startup so typos
+  fail loudly.
+- **Environment variable expansion** — `${VAR_NAME}` and `$VAR_NAME` in the TOML
+  file keep SMTP credentials out of version control.
+- **IPv6-first** — binds to `[::]` by default, with automatic IPv4 compatibility
+  via dual-stack sockets.
+- **Cross-platform** — pre-built binaries for Linux (amd64, arm64, riscv64,
+  loong64) and FreeBSD (amd64, arm64, riscv64) on every release.
 
-```bash
+## Configuration
-# Contact form
-curl -X POST http://localhost:8080/api/nuntius/contact \
-  -H "Content-Type: application/json" \
-  -H "Origin: https://petrbalvin.org" \
-  -d '{
-    "name": "Jane Doe",
-    "email": "jane@example.com",
-    "service": "architecture",
-    "message": "Hello, I would like to discuss an engagement."
-  }'
 
-# Feedback (no service field)
+Default path: `/etc/nuntius/config.toml`. A starter file is written automatically
-curl -X POST http://localhost:8080/api/nuntius/feedback \
+on first start.
-  -H "Content-Type: application/json" \
-  -H "Origin: https://petrbalvin.org" \
-  -d '{
-    "name": "Jane Doe",
-    "email": "jane@example.com",
-    "message": "I love how the site uses Vue.js with zero runtime deps."
-  }'
-
-# Newsletter (email only)
-curl -X POST http://localhost:8080/api/nuntius/newsletter \
-  -H "Content-Type: application/json" \
-  -H "Origin: https://petrbalvin.org" \
-  -d '{ "email": "jane@example.com" }'
-```
-
-Successful response (all three):
-
-```json
-{ "ok": true }
-```
-
-Validation error (e.g. newsletter with bad email):
-
-```json
-{
-  "error": "validation",
-  "details": [
-    { "field": "email", "message": "email is invalid" }
-  ]
-}
-```
-
-### Frontend integration
-
-If you proxy `/api/nuntius/*` through nginx (recommended, see [`docs/deployment.md`](docs/deployment.md)), no frontend config is needed — the form posts to the same origin as the page. Otherwise, set `VITE_NUNTIUS_URL` to the upstream origin:
-
-```js
-await fetch(`${import.meta.env.VITE_NUNTIUS_URL || ''}/api/nuntius/contact`, {
-  method: 'POST',
-  headers: { 'Content-Type': 'application/json' },
-  body: JSON.stringify({
-    name: name.value,
-    email: email.value,
-    service: service.value,
-    message: message.value,
-  }),
-});
-```
-
-### Use the package in your own project
-
-`pkg/contactform` is a small, dependency-free Go package that you can import into any project:
-
-```go
-import "codeberg.org/petrbalvin/nuntius/pkg/contactform"
-
-req := &contactform.Request{
-    Name:    "Jane",
-    Email:   "jane@example.com",
-    Service: "architecture",
-    Message: "Hello!",
-}
-
-if errs := contactform.Validate(req, "contact"); len(errs) > 0 {
-    // handle validation errors
-}
-```
-
-Full library example: [`docs/library-usage.md`](docs/library-usage.md). Full HTTP API: [`docs/api-reference.md`](docs/api-reference.md).
-
-## Configuration (TL;DR)
-
-Default path: `/etc/nuntius/config.toml`. A starter file is written automatically on first start.
 
 ```toml
 data_dir = "./data"
@@ -164,44 +102,139 @@ allowed_origins = ["https://example.com"]
   password = "${NUNTIUS_SMTP_PASSWORD}"
 ```
 
-Form types and full schema: [`docs/configuration.md`](docs/configuration.md). Secrets via env vars, CORS, honeypot, rate limit, and validation rules are all documented there.
+Secrets are injected via environment variables using `${VAR_NAME}` syntax. The
+full schema, form types, validation rules, and newsletter log format are
+documented in [`docs/configuration.md`](docs/configuration.md).
 
-## Requirements
+## Form Types
 
-- **Go 1.26+** (uses Go 1.22+ `http.ServeMux` method patterns and `log/slog`)
+| Type | Required fields | Email subject | Stores to disk |
-- An **SMTP** account (Yandex, Mailgun, Postmark, your own Postfix, …)
+|------|-----------------|---------------|:---:|
-- **No other runtime dependencies.** No Node, no Python, no Redis, no Postgres. Configuration is TOML parsed via the first-party [`interpres`](https://codeberg.org/petrbalvin/interpres) library; newsletter storage is an append-only JSONL file via `bufio`.
+| `contact` | `name`, `email`, `message`; optional `service` | `[nuntius/<name>] Contact form submission` | |
+| `feedback` | `name`, `email`, `message` | `[nuntius/<name>] New feedback` | |
+| `newsletter` | `email` | `[nuntius/<name>] New newsletter subscriber` | ✓ |
+| `generic` | `name`, `email`, `message` | `[nuntius/<name>] New submission` | |
+
+All four types are rate-limited, CORS-checked, and honeypot-protected
+independently — each form has its own per-IP bucket, allowlist, and honeypot
+field. `newsletter` is the only type that writes to disk; the other three only
+send email.
+
+The `contact` form restricts the `service` field to an allow-list:
+`architecture`, `ai`, `infrastructure`, `software`, `unix`, `other`, or empty.
+
+Full form type documentation: [`docs/configuration.md#form-types`](docs/configuration.md#form-types).
+
+## Security
+
+Every form endpoint is protected independently:
+
+- **Honeypot** — a configurable invisible form field silently drops submissions
+  that contain it. Enabled per form via `honeypot_field`.
+- **CORS** — per-form `allowed_origins` list. Requests from disallowed origins
+  receive a `403 Forbidden`.
+- **Rate limiting** — token-bucket algorithm, per IP, per form, configurable
+  submissions per hour. In-memory; no Redis required. Set `rate_limit_per_hour`
+  to `0` to disable for a given form.
+- **Server timeouts** — `ReadHeaderTimeout` prevents slow-loris attacks;
+  graceful shutdown deadline ensures in-flight requests are drained before exit.
+- **Secret hygiene** — SMTP credentials are never logged; TOML values use
+  `${VAR_NAME}` expansion so passwords stay in the environment, not on disk.
+- **Config validation** — unknown TOML fields and unknown form types cause a
+  startup failure, preventing typo-driven misconfigurations from reaching
+  production.
+- **Input validation** — server-side validation of all fields with configurable
+  length limits; trimmed whitespace; RFC 5322 email parsing.
+
+For a full threat model and detailed security discussion, see
+[`docs/security.md`](docs/security.md). To report a vulnerability privately,
+email **opensource@petrbalvin.org**.
+
+## Production Deployment
+
+Build the binary on your workstation, upload it with the systemd unit and
+environment template to your server, then run `python3 install.py` as root. The
+script is idempotent and sets up:
+
+- A dedicated `nuntius` system user and group
+- The binary at `/usr/local/bin/nuntius`
+- Config auto-generation at `/etc/nuntius/config.toml`
+- Environment file at `/etc/nuntius/.env` (mode `0600`)
+- A systemd service unit at `/etc/systemd/system/nuntius.service`
+- Data directory at `/var/lib/nuntius`
+
+The service is **enabled but not started** — you review the config and
+environment file first, then start it manually.
+
+Complete deployment instructions including Caddy reverse-proxy configuration,
+TLS setup, log rotation, and updates are in
+[`docs/deployment.md`](docs/deployment.md).
+
+## Library Usage
+
+The `pkg/contactform` package is a small, dependency-free Go library you can
+import into any project:
+
+```go
+import "sourcedock.dev/petrbalvin/nuntius/pkg/contactform"
+
+req := &contactform.Request{
+    Name:    "Jane",
+    Email:   "jane@example.com",
+    Service: "architecture",
+    Message: "Hello, I would like to discuss an engagement.",
+}
+
+if errs := contactform.Validate(req, "contact"); len(errs) > 0 {
+    // handle validation errors
+}
+```
+
+The package exports typed `Request`, `Response`, and `ErrorResponse` structs,
+the `Validate` function, and all form kind constants. A full standalone example
+is in [`docs/library-usage.md`](docs/library-usage.md).
 
 ## Development
 
 ```bash
-just install        # go mod tidy + go mod download (no-op for this project, kept for symmetry)
+just install   # go mod tidy + go mod download
-just build          # → ./bin/nuntius (with -s -w)
+just build     # → ./bin/nuntius (stripped, -s -w)
-just test           # go test ./...
+just test      # go test -race ./...; enforces ≥80% coverage on internal + pkg
-just run            # go run ./cmd/server
+just fmt       # gofmt -w cmd internal pkg
-just uninstall      # rm -rf ./bin
+just run       # go run ./cmd/server
 ```
 
-All four `just` recipes are mandatory per the project conventions and produce zero errors and zero warnings.
+All `just` recipes produce zero errors and zero warnings. Tests include the race
+detector and enforce an 80% coverage floor on the `internal` and `pkg` packages.
+
+The CI pipeline (Gitea Actions, `.gitea/workflows/`) runs the full test suite
+and performs a multi-platform build matrix on every release tag
+(`linux/amd64`, `linux/arm64`, `linux/riscv64`, `linux/loong64`, `freebsd/amd64`,
+`freebsd/arm64`, `freebsd/riscv64`).
+
+## Requirements
+
+- **Go 1.26+**
+- An **SMTP** account (any standards-compliant provider — Postfix, Yandex 360,
+  Mailgun, Postmark, etc.)
+- **No other runtime dependencies.** No Node, no Python, no Redis, no Postgres.
+  Config is TOML parsed by the first-party
+  [`interpres`](https://sourcedock.dev/petrbalvin/interpres) library; newsletter
+  storage is an append-only JSONL file via `bufio`; rate limiting is in-memory.
 
 ## Documentation
 
 - [`docs/architecture.md`](docs/architecture.md) — layers, request flow, design decisions
 - [`docs/configuration.md`](docs/configuration.md) — full config schema, form types, secrets, newsletter log
 - [`docs/api-reference.md`](docs/api-reference.md) — HTTP verbs, status codes, `GET /health`
-- [`docs/deployment.md`](docs/deployment.md) — production systemd, nginx, updates
+- [`docs/deployment.md`](docs/deployment.md) — production systemd, Caddy, updates
 - [`docs/security.md`](docs/security.md) — threat model, CORS, rate limiting, secret handling
-- [`docs/library-usage.md`](docs/library-usage.md) — `pkg/contactform` API and standalone use
+- [`docs/library-usage.md`](docs/library-usage.md) — `pkg/contactform` API and standalone usage
 
 ## Contributing
 
-See [`CONTRIBUTING.md`](CONTRIBUTING.md) for development setup, code style, commit conventions, and the pull request flow.
+See [`CONTRIBUTING.md`](CONTRIBUTING.md) for development setup, code style, commit
-
+conventions, and the pull request flow.
-## Security
-
-For a full threat model, see [`docs/security.md`](docs/security.md). The short version: every form has its own per-IP rate limit, CORS allowlist, and honeypot field; SMTP credentials never touch the log; unknown config fields are rejected at startup.
-
-If you find a security issue, please email **opensource@petrbalvin.org** rather than opening a public issue.
 
 ## License
 

cmd/server/main.go

@@ -1,3 +1,6 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: MIT
+
 //go:build linux || freebsd
 
 // Command nuntius runs the contact form backend server.
@@ -19,9 +22,9 @@ import (
 	"syscall"
 	"time"
 
-	"codeberg.org/petrbalvin/nuntius/internal/config"
+	"sourcedock.dev/petrbalvin/nuntius/internal/config"
-	"codeberg.org/petrbalvin/nuntius/internal/handler"
+	"sourcedock.dev/petrbalvin/nuntius/internal/handler"
-	"codeberg.org/petrbalvin/nuntius/internal/version"
+	"sourcedock.dev/petrbalvin/nuntius/internal/version"
 )
 
 func main() {
@@ -48,7 +51,7 @@ func main() {
 	h.Register(mux)
 
 	srv := &http.Server{
-		Addr:              ":" + itoa(cfg.Server.Port),
+		Addr:              "[::]:" + itoa(cfg.Server.Port),
 		Handler:           withRequestLog(mux, logger),
 		ReadHeaderTimeout: 10 * time.Second,
 		ReadTimeout:       15 * time.Second,

cmd/server/main_test.go

@@ -0,0 +1,118 @@
+//go:build linux || freebsd
+
+package main
+
+import (
+	"io"
+	"log/slog"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestItoa(t *testing.T) {
+	tests := []struct {
+		n    int
+		want string
+	}{
+		{0, "0"},
+		{1, "1"},
+		{9, "9"},
+		{10, "10"},
+		{42, "42"},
+		{100, "100"},
+		{-1, "-1"},
+		{-42, "-42"},
+		{8080, "8080"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.want, func(t *testing.T) {
+			if got := itoa(tt.n); got != tt.want {
+				t.Errorf("itoa(%d) = %q, want %q", tt.n, got, tt.want)
+			}
+		})
+	}
+}
+
+func TestLast(t *testing.T) {
+	tests := []struct {
+		s    string
+		c    byte
+		want int
+	}{
+		{"hello", 'l', 3},
+		{"hello", 'o', 4},
+		{"hello", 'h', 0},
+		{"hello", 'x', -1},
+		{"", 'a', -1},
+		{"aaa", 'a', 2},
+	}
+
+	for _, tt := range tests {
+		if got := last(tt.s, tt.c); got != tt.want {
+			t.Errorf("last(%q, %q) = %d, want %d", tt.s, tt.c, got, tt.want)
+		}
+	}
+}
+
+func TestClientIP(t *testing.T) {
+	tests := []struct {
+		name       string
+		remoteAddr string
+		want       string
+	}{
+		{"ipv4 with port", "192.168.1.1:12345", "192.168.1.1"},
+		{"ipv6 with brackets", "[::1]:12345", "[::1]"},
+		{"ipv4 without port", "192.168.1.1", "192.168.1.1"},
+		{"empty", "", ""},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			req := httptest.NewRequest(http.MethodGet, "/", nil)
+			req.RemoteAddr = tt.remoteAddr
+			if got := clientIP(req); got != tt.want {
+				t.Errorf("clientIP() = %q, want %q", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestStatusRecorder(t *testing.T) {
+	rec := httptest.NewRecorder()
+	sr := &statusRecorder{ResponseWriter: rec, status: http.StatusOK}
+
+	// Default status before WriteHeader.
+	if sr.status != http.StatusOK {
+		t.Errorf("initial status = %d, want %d", sr.status, http.StatusOK)
+	}
+
+	sr.WriteHeader(http.StatusNotFound)
+	if sr.status != http.StatusNotFound {
+		t.Errorf("status after WriteHeader = %d, want %d", sr.status, http.StatusNotFound)
+	}
+
+	// rec should also have the status set.
+	if rec.Code != http.StatusNotFound {
+		t.Errorf("rec.Code = %d, want %d", rec.Code, http.StatusNotFound)
+	}
+}
+
+func TestWithRequestLog(t *testing.T) {
+	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+	})
+
+	logger := slog.New(slog.NewTextHandler(io.Discard, nil))
+	wrapped := withRequestLog(handler, logger)
+	req := httptest.NewRequest(http.MethodGet, "/test", nil)
+	req.RemoteAddr = "192.168.1.1:12345"
+	rec := httptest.NewRecorder()
+
+	wrapped.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Errorf("status = %d, want 200", rec.Code)
+	}
+}

docs/api-reference.md

@@ -172,7 +172,7 @@ The IP used for rate limiting is taken from the same precedence chain as the log
 2. `X-Real-IP`
 3. `RemoteAddr` (with the port stripped)
 
-Behind nginx, set `proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;` so the bucket sees the real client IP.
+Caddy forwards `X-Forwarded-For` automatically — so the real client IP is always passed to nuntius without any extra configuration.
 
 ## Health Check
 

docs/architecture.md

@@ -7,7 +7,7 @@
 ```mermaid
 graph TD
     Browser[Browser / Frontend]:::accent6
-    Nginx[nginx reverse proxy]:::accent6
+    Caddy[Caddy reverse proxy]:::accent6
     Server[cmd/server/main.go]:::accent0
     Config[internal/config/]:::accent7
     Handler[internal/handler/]:::accent0
@@ -20,8 +20,8 @@ graph TD
     SMTP[(SMTP server)]:::accent2
     JSONL[(data_dir/newsletter-*.jsonl)]:::accent2
 
-    Browser -->|POST + Origin| Nginx
+    Browser -->|POST + Origin| Caddy
-    Nginx -->|X-Forwarded-For| Server
+    Caddy -->|X-Forwarded-For| Server
     Server --> Config
     Server --> Handler
     Handler --> RateLimit
@@ -32,8 +32,8 @@ graph TD
     Handler --> Storage
     Sender -->|SMTP PLAIN over net/smtp| SMTP
     Storage -->|append JSONL| JSONL
-    Handler -->|200 / 4xx / 5xx| Nginx
+    Handler -->|200 / 4xx / 5xx| Caddy
-    Nginx --> Browser
+    Caddy --> Browser
 
     classDef accent0 fill:#3B82F6,stroke:#2563EB,color:#fff
     classDef accent1 fill:#22C55E,stroke:#16A34A,color:#fff
@@ -74,14 +74,28 @@ The `Form` type mirrors the TOML shape one-to-one. `ValidFormTypes` is the autho
 
 ### 3. HTTP handler — `internal/handler/`
 
+`ContactHandler` stores its dependencies behind small interfaces so the handler pipeline can be tested without a real SMTP server or filesystem:
+
+```go
+type formSender interface {
+    Send(req contactform.Request) error
+}
+
+type subscriberStorer interface {
+    Append(sub storage.Subscriber) error
+}
+```
+
+`email.FormSender` and `storage.NewsletterStore` satisfy these interfaces in production. Tests use mock implementations (`mockSender`, `mockStore`) that record calls and simulate errors.
+
 `ContactHandler` is a single struct with four maps keyed by URL path:
 
 ```go
 type ContactHandler struct {
     forms      map[string]*config.Form
-    senders    map[string]*email.FormSender
+    senders    map[string]formSender
     rateLimits map[string]*rateLimiter
-    stores     map[string]*storage.NewsletterStore
+    stores     map[string]subscriberStorer
 }
 ```
 
@@ -142,6 +156,10 @@ sequenceDiagram
     end
 ```
 
+### Rate limiter cleanup
+
+The per-form `rateLimiter` type starts a background goroutine (`startCleanup`) that ticks once per hour and deletes IP entries older than twice the refill window. This prevents unbounded memory growth from one-off IPs. The cleanup goroutine is covered by `TestRateLimiterCleanup` in `contact_test.go`.
+
 Notable behaviors:
 
 - **CORS is path-aware** — Each form has its own `allowed_origins` list; preflights and actual requests are checked against the form being hit, not the host.
@@ -182,13 +200,13 @@ There is **no rotation**. Add a `logrotate` unit if the file grows beyond what y
 ```mermaid
 sequenceDiagram
     participant Browser
-    participant Nginx
+    participant Caddy
     participant Nuntius as nuntius
     participant SMTP
     participant Disk
 
-    Browser->>Nginx: POST /api/nuntius/contact
+    Browser->>Caddy: POST /api/nuntius/contact
-    Nginx->>Nuntius: forward (X-Forwarded-For, X-Real-IP)
+    Caddy->>Nuntius: forward (X-Forwarded-For, X-Real-IP)
     Nuntius->>Nuntius: CORS check
     Nuntius->>Nuntius: rate-limit per IP
     Nuntius->>Nuntius: parse JSON
@@ -199,8 +217,8 @@ sequenceDiagram
     opt newsletter form
         Nuntius->>Disk: append one JSONL line
     end
-    Nuntius-->>Nginx: 200 {"ok": true}
+    Nuntius-->>Caddy: 200 {"ok": true}
-    Nginx-->>Browser: 200 {"ok": true}
+    Caddy-->>Browser: 200 {"ok": true}
 ```
 
 ## Config Merging

docs/configuration.md

@@ -160,7 +160,7 @@ NUNTIUS_SMTP_PASSWORD=actual-app-password
 EnvironmentFile=/etc/nuntius/.env
 ```
 
-The `install.sh` helper script sets the file mode automatically.
+The `install.py` helper script sets the file mode automatically.
 
 ## Defaults at a Glance
 

docs/deployment.md

@@ -1,6 +1,6 @@
 # Production Deployment
 
-This guide covers installing nuntius on a Linux server with `nginx`, `systemd`, and `rsync` already in place — the same setup used by [petrbalvin.org](https://www.petrbalvin.org). The same `rsync -avz` workflow that ships the static website works for nuntius with no changes.
+This guide covers installing nuntius on a Linux server with `Caddy`, `systemd`, and `rsync` already in place — the same setup used by [petrbalvin.org](https://www.petrbalvin.org). The same `rsync -avz` workflow that ships the static website works for nuntius with no changes.
 
 ## Architecture in Production
 
@@ -8,21 +8,21 @@ This guide covers installing nuntius on a Linux server with `nginx`, `systemd`,
 graph LR
     Browser[Visitor's browser]:::accent6
     Internet((Internet)):::accent2
-    Nginx[nginx :443]:::accent0
+    Caddy[Caddy :443]:::accent0
     Nuntius[nuntius :8080]:::accent1
     Systemd[systemd unit]:::accent7
     SMTP[(SMTP provider)]:::accent2
     Disk[(/var/lib/nuntius/data/*.jsonl)]:::accent2
 
     Browser --> Internet
-    Internet --> Nginx
+    Internet --> Caddy
-    Nginx -->|proxy_pass /api/nuntius/| Nuntius
+    Caddy -->|reverse_proxy /api/nuntius/| Nuntius
     Systemd -.->|manages| Nuntius
     Nuntius -->|SMTP PLAIN| SMTP
     Nuntius -->|append JSONL| Disk
 ```
 
-nuntius listens on `127.0.0.1:8080` (default). nginx terminates TLS on `:443` and proxies `/api/nuntius/*` to the upstream. systemd restarts the process on failure.
+nuntius binds `[::]:8080` by default — the dual-stack IPv6 wildcard that accepts both IPv4 and IPv6 connections on Linux and FreeBSD. Caddy should be configured to proxy to `[::1]:8080` or `127.0.0.1:8080` for loopback-only access.
 
 ## 1. Build and Upload (Local Machine)
 
@@ -37,7 +37,7 @@ rsync -avz \
     user@your-server:/tmp/nuntius/
 ```
 
-> `install.sh` lives in the repository root. The systemd unit is included inline in Option A below (you do not need to rsync it from the repo). `.env.example` is a template for the secrets file. Adjust the `rsync` source list to match what you keep checked in.
+> `install.py` lives in the repository root. The systemd unit is included inline in Option A below (you do not need to rsync it from the repo). `.env.example` is a template for the secrets file. Adjust the `rsync` source list to match what you keep checked in.
 
 ## 2. Install on the Server (SSH Session)
 
@@ -97,7 +97,7 @@ sudo journalctl -u nuntius -f
 
 The service file expects the binary at `/usr/local/bin/nuntius`, the env file at `/etc/nuntius/.env`, and the data dir at `/var/lib/nuntius` (the config's `data_dir: "./data"` resolves to `/var/lib/nuntius/data` because the unit sets `WorkingDirectory=/var/lib/nuntius`). If you'd rather use `/opt/nuntius/...` or any other layout, edit the systemd unit block above before installing.
 
-### Option B — `install.sh` (idempotent)
+### Option B — `install.py` (idempotent)
 
 Before running the script, copy the systemd unit from the block in Option A above into `/tmp/nuntius/nuntius.service` (the script reads it from the current working directory):
 
@@ -106,7 +106,7 @@ ssh user@your-server
 cd /tmp/nuntius
 # Paste the [Unit]…[Install] block from Option A into this file:
 sudo $EDITOR /tmp/nuntius/nuntius.service
-sudo bash install.sh
+sudo python3 install.py
 ```
 
 The script is idempotent: re-running on an already-installed host is safe. It:
@@ -121,35 +121,31 @@ The script is idempotent: re-running on an already-installed host is safe. It:
 
 The script ends with the exact next steps you need to run by hand.
 
-## 3. nginx Reverse Proxy
+## 3. Caddy Reverse Proxy
 
-Add this location block to the same nginx server that already serves your site (most likely `/etc/nginx/sites-available/petrbalvin.org`):
+Add this directive to your Caddyfile (most likely `/etc/caddy/Caddyfile`):
 
-```nginx
+```caddyfile
-location /api/nuntius/ {
+handle_path /api/nuntius/* {
-    proxy_pass http://127.0.0.1:8080/api/nuntius/;
+    reverse_proxy 127.0.0.1:8080
-    proxy_set_header Host              $host;
-    proxy_set_header X-Real-IP         $remote_addr;
-    proxy_set_header X-Forwarded-For   $proxy_add_x_forwarded_for;
-    proxy_set_header X-Forwarded-Proto $scheme;
 }
 ```
 
 Then:
 
 ```bash
-sudo nginx -t
+sudo caddy validate
-sudo systemctl reload nginx
+sudo systemctl reload caddy
 ```
 
-Without `X-Forwarded-For`, the rate limiter will see every request as coming from `127.0.0.1` and effectively become useless once the form is live. The `Host` header also matters for vhost-aware upstreams; the default is fine for a single nuntius instance.
+Caddy forwards `X-Forwarded-For` automatically — so the real client IP is always passed to nuntius without any extra configuration.
 
 ## 4. Wire It Up to Your Web
 
-If you proxy `/api/nuntius/*` through nginx (recommended, step 3 above), `VITE_NUNTIUS_URL` can stay empty and the form will post to the same origin as the page. Otherwise, set it to the bare upstream URL:
+If you proxy `/api/nuntius/*` through Caddy (recommended, step 3 above), `VITE_NUNTIUS_URL` can stay empty and the form will post to the same origin as the page. Otherwise, set it to the bare upstream URL:
 
 ```bash
-# .env (in the web project, only needed if NOT proxying through nginx)
+# .env (in the web project, only needed if NOT proxying through Caddy)
 VITE_NUNTIUS_URL=https://your-server:8080
 ```
 
@@ -227,10 +223,10 @@ curl -s http://127.0.0.1:8080/health | jq .
 # Recent log lines
 journalctl -u nuntius -n 50 --no-pager
 
-# nginx proxy works
+# Caddy proxy works
 curl -i https://your-domain.example/api/nuntius/health
 
-# End-to-end POST through nginx
+# End-to-end POST through Caddy
 curl -X POST https://your-domain.example/api/nuntius/contact \
   -H "Content-Type: application/json" \
   -H "Origin: https://your-domain.example" \

docs/library-usage.md

@@ -5,7 +5,7 @@
 ## Installation
 
 ```bash
-go get codeberg.org/petrbalvin/nuntius/pkg/contactform
+go get sourcedock.dev/petrbalvin/nuntius/pkg/contactform
 ```
 
 Because nuntius ships with no `go.sum` entries from third-party modules, this import pulls in only stdlib transitively.
@@ -118,7 +118,7 @@ import (
     "fmt"
     "os"
 
-    "codeberg.org/petrbalvin/nuntius/pkg/contactform"
+    "sourcedock.dev/petrbalvin/nuntius/pkg/contactform"
 )
 
 func main() {
@@ -175,7 +175,7 @@ import (
     "log"
     "net/http"
 
-    "codeberg.org/petrbalvin/nuntius/pkg/contactform"
+    "sourcedock.dev/petrbalvin/nuntius/pkg/contactform"
 )
 
 func contactHandler(w http.ResponseWriter, r *http.Request) {

docs/security.md

@@ -9,7 +9,7 @@ nuntius is designed to defend against:
 | Threat | Mitigation |
 |---|---|
 | Naive spam bots filling the form | Per-form honeypot field that silently accepts and drops |
-| Casual brute-force / abuse | Per-form, per-IP token-bucket rate limit (in-memory) |
+| Casual brute-force / abuse | Per-form, per-IP token-bucket rate limit (in-memory, with periodic cleanup goroutine) |
 | Cross-origin abuse from a third-party site | Per-form CORS allowlist enforced on preflight and actual requests |
 | Malformed bodies | Strict JSON parsing and per-type field validation |
 | SMTP credential leakage in logs | `log/slog` never logs the `From` / `Authorization` / password; the password only lives in `FormSender` |
@@ -81,12 +81,14 @@ The IP used is taken from:
 2. `X-Real-IP`
 3. `RemoteAddr` (with port stripped)
 
-Behind nginx, set `proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;` — otherwise every request looks like it came from `127.0.0.1` and the bucket becomes a single global bucket.
+Caddy forwards `X-Forwarded-For` automatically — so the real client IP is always passed to nuntius without any extra configuration.
 
 To disable rate limiting on a specific form, set `rate_limit_per_hour: 0`. There is no global safety net.
 
 State is per-process and resets on restart. If you scale nuntius horizontally, each replica has its own bucket; the effective limit is `replicas × per_form_limit`.
 
+A background goroutine (`startCleanup`) ticks once per hour and removes IP entries that are older than twice the refill window. This prevents the in-memory bucket map from growing unboundedly as one-off IPs accumulate over weeks of uptime.
+
 ## Secret Handling
 
 SMTP credentials live in `/etc/nuntius/.env` (mode `0600`, owner `root:nuntius`). The config file references them as `${NUNTIUS_SMTP_PASSWORD}`; `os.Expand` substitutes them **before** the TOML is parsed, so the parsed `config.Form` holds the expanded value in memory only for the lifetime of the process.
@@ -100,7 +102,7 @@ Things nuntius does **not** do:
 
 Things you should do:
 
-- Make sure `/etc/nuntius/.env` is `0600` and owned `root:nuntius` (the `install.sh` script does this for you).
+- Make sure `/etc/nuntius/.env` is `0600` and owned `root:nuntius` (the `install.py` script does this for you).
 - Use an app-specific password or OAuth token if your provider supports it. nuntius uses `PLAIN` auth because that is what every SMTP provider offers; the credential is the secret, not the auth mechanism.
 - Rotate the password on the same cadence as any other production secret.
 - Restrict read access to `journalctl -u nuntius` if you do not want the client IPs in your local log files.
@@ -133,10 +135,10 @@ The graceful shutdown budget is 15 s (`srv.Shutdown` with `context.WithTimeout`)
 - **No CAPTCHA / proof-of-work.** If you need a stronger abuse signal, add a reverse proxy with a CAPTCHA in front of nuntius; the same CORS rules apply.
 - **No request signing / HMAC.** A frontend that has been compromised can post at the configured rate from a single IP. The token bucket handles the volume; the origin allowlist limits the surface.
 - **No per-IP persistence across restarts.** Restart resets the buckets. That is an acceptable trade-off for a small backend and is documented in the rate-limit section above.
-- **No TLS for the nuntius listener itself.** nuntius is meant to run behind nginx (or another reverse proxy) that terminates TLS. Exposing the binary directly on `:8080` is a development convenience, not a production pattern.
+- **No TLS for the nuntius listener itself.** nuntius binds `[::]:8080` (the dual-stack IPv6 wildcard) and is meant to run behind Caddy (or another reverse proxy) that terminates TLS. Exposing the binary directly is a development convenience, not a production pattern.
 - **No DKIM signing.** Outbound mail is signed by your SMTP provider, not by nuntius.
 - **No TLS for the SMTP connection itself is configured by nuntius.** Go's `net/smtp.SendMail` opportunistically upgrades to TLS via STARTTLS when the server advertises it; if you need implicit TLS on `:465`, wrap `SendMail` in a custom dialer.
 
 ## Reporting a Vulnerability
 
-Email **petrbalvin@yandex.com** with a description and a reproducer. Please do not file a public issue for security-sensitive reports.
+Email **opensource@petrbalvin.org** with a description and a reproducer. Please do not file a public issue for security-sensitive reports.

examples/minimal/main.go

@@ -1,3 +1,6 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: MIT
+
 //go:build linux || freebsd
 
 // Minimal example showing how to use the contactform package
@@ -8,7 +11,7 @@ import (
 	"fmt"
 	"os"
 
-	"codeberg.org/petrbalvin/nuntius/pkg/contactform"
+	"sourcedock.dev/petrbalvin/nuntius/pkg/contactform"
 )
 
 func main() {

go.mod

@@ -1,5 +1,5 @@
-module codeberg.org/petrbalvin/nuntius
+module sourcedock.dev/petrbalvin/nuntius
 
 go 1.26
 
-require codeberg.org/petrbalvin/interpres v1.0.0
+require sourcedock.dev/petrbalvin/interpres v1.1.1

go.sum

@@ -1,2 +1,2 @@
-codeberg.org/petrbalvin/interpres v1.0.0 h1:bnY6zSekKklss+w/95O/0GCO1col05pV4HE8JsVXQN4=
+sourcedock.dev/petrbalvin/interpres v1.1.1 h1:W0HYj8kHikuy1BZePPL4RaSEuv3TNX7YpdP1vvpkP54=
-codeberg.org/petrbalvin/interpres v1.0.0/go.mod h1:sWgi5ijKNNLu5sCtjix9jG/guhdnDRlROENrFhrIt90=
+sourcedock.dev/petrbalvin/interpres v1.1.1/go.mod h1:kyJWrbwVykxCiW250V6zZO2QUKNlAeFn+pwqzr+Hn2U=

install.py

@@ -0,0 +1,265 @@
+#!/usr/bin/env python3
+# Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+# SPDX-License-Identifier: MIT
+#
+# install.py — install nuntius as a systemd service.
+#
+# nuntius ships as a single static binary. Build it on your workstation, upload
+# the binary, the systemd unit, and the .env template to the server, then run
+# this script there as root from that directory:
+#
+#   scp bin/nuntius nuntius.service .env.example user@host:/tmp/nuntius/
+#   ssh user@host
+#   cd /tmp/nuntius && sudo python3 install.py
+#
+# It expects ./nuntius and ./nuntius.service (and optionally ./.env.example) in
+# the current working directory. Idempotent: re-running is safe — it skips the
+# user, config, and .env when they already exist, and never starts the service.
+
+from __future__ import annotations
+
+import argparse
+import logging
+import os
+import shutil
+import subprocess
+import sys
+from typing import NoReturn
+
+NUNTIUS_USER = "nuntius"
+BIN_DEST = "/usr/local/bin/nuntius"
+CONFIG_DIR = "/etc/nuntius"
+CONFIG_FILE = "/etc/nuntius/config.toml"
+ENV_FILE = "/etc/nuntius/.env"
+DATA_DIR = "/var/lib/nuntius"
+SERVICE_DEST = "/etc/systemd/system/nuntius.service"
+
+# ---------------------------------------------------------------------------
+# Coloured logging
+# ---------------------------------------------------------------------------
+
+
+class _ColourFormatter(logging.Formatter):
+    """Prefix each log line with a coloured level marker, mimicking the bash script."""
+
+    _COLOURS: dict[int, str] = {
+        logging.INFO: "\033[1;34m",  # blue
+        logging.WARNING: "\033[1;33m",  # yellow
+        logging.ERROR: "\033[1;31m",  # red
+    }
+    _LABELS: dict[int, str] = {
+        logging.INFO: "==>",
+        logging.WARNING: "WARN:",
+        logging.ERROR: "ERROR:",
+    }
+    _RESET = "\033[0m"
+
+    def format(self, record: logging.LogRecord) -> str:
+        colour = self._COLOURS.get(record.levelno, "")
+        label = self._LABELS.get(record.levelno, "")
+        if colour and label:
+            return f"{colour}{label}{self._RESET} {record.getMessage()}"
+        return record.getMessage()
+
+
+def _setup_logging() -> None:
+    """Configure the root logger with coloured console output."""
+    logger = logging.getLogger()
+    logger.setLevel(logging.INFO)
+    handler = logging.StreamHandler()
+    handler.setFormatter(_ColourFormatter())
+    # Remove any handlers added by basicConfig or other imports.
+    logger.handlers.clear()
+    logger.addHandler(handler)
+
+
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+
+
+def _run(cmd: list[str], **kwargs: object) -> subprocess.CompletedProcess[str]:
+    """Run a command via subprocess and check for failure (unless told otherwise)."""
+    return subprocess.run(cmd, check=True, text=True, **kwargs)
+
+
+# ---------------------------------------------------------------------------
+# Install steps
+# ---------------------------------------------------------------------------
+
+
+def require_root() -> None:
+    """Exit if not running as root."""
+    if os.geteuid() != 0:
+        logging.error("Run as root: sudo python3 install.py")
+        sys.exit(1)
+
+
+def require_files() -> None:
+    """Verify that the binary and the systemd unit are present in CWD."""
+    if not os.path.isfile("./nuntius"):
+        logging.error(
+            "./nuntius binary not found — copy it here first (e.g. rsync bin/nuntius)."
+        )
+        sys.exit(1)
+    if not os.path.isfile("./nuntius.service"):
+        logging.error(
+            "./nuntius.service not found — paste the unit from docs/deployment.md (Option A)."
+        )
+        sys.exit(1)
+
+
+def create_user() -> None:
+    """Create the system user if it does not already exist."""
+    try:
+        _run(["id", NUNTIUS_USER], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
+        logging.info("User %s already exists.", NUNTIUS_USER)
+    except subprocess.CalledProcessError:
+        logging.info("Creating system user %s…", NUNTIUS_USER)
+        _run(
+            [
+                "useradd",
+                "--system",
+                "--shell",
+                "/usr/sbin/nologin",
+                "--home-dir",
+                DATA_DIR,
+                "--user-group",
+                NUNTIUS_USER,
+            ]
+        )
+
+
+def create_data_dir() -> None:
+    """Ensure the data directory exists with correct ownership and permissions."""
+    logging.info("Setting up %s…", DATA_DIR)
+    os.makedirs(DATA_DIR, exist_ok=True)
+    shutil.chown(DATA_DIR, user=NUNTIUS_USER, group=NUNTIUS_USER)
+    os.chmod(DATA_DIR, 0o750)
+
+
+def install_binary() -> None:
+    """Copy the nuntius binary to /usr/local/bin with mode 0755."""
+    logging.info("Installing binary to %s…", BIN_DEST)
+    shutil.copy2("./nuntius", BIN_DEST)
+    os.chmod(BIN_DEST, 0o755)
+
+
+def install_service() -> None:
+    """Copy the systemd unit file with mode 0644."""
+    logging.info("Installing systemd unit %s…", SERVICE_DEST)
+    shutil.copy2("./nuntius.service", SERVICE_DEST)
+    os.chmod(SERVICE_DEST, 0o644)
+
+
+def generate_config() -> None:
+    """Auto-generate the TOML config by running nuntius briefly if config is absent."""
+    if os.path.isfile(CONFIG_FILE):
+        logging.info("Config %s already exists; leaving it untouched.", CONFIG_FILE)
+        return
+
+    logging.info("Generating %s…", CONFIG_FILE)
+    os.makedirs(CONFIG_DIR, exist_ok=True)
+
+    # nuntius writes the template config on first start; run it briefly, then
+    # let `timeout` send SIGTERM (graceful shutdown). The write happens at
+    # startup, before the timeout elapses.
+    try:
+        _run(["timeout", "-k", "5s", "4s", BIN_DEST], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
+    except subprocess.CalledProcessError:
+        # timeout exits 124 on SIGTERM, 137 on SIGKILL — both are expected.
+        pass
+
+    if not os.path.isfile(CONFIG_FILE):
+        logging.warning("nuntius did not create %s; check the uploaded binary.", CONFIG_FILE)
+
+    # Fix ownership in case nuntius wrote files as root.
+    _run(["chown", "-R", f"{NUNTIUS_USER}:{NUNTIUS_USER}", DATA_DIR])
+
+
+def install_env() -> None:
+    """Copy .env.example to /etc/nuntius/.env if it does not already exist."""
+    if os.path.isfile(ENV_FILE):
+        logging.info("%s already exists; leaving it untouched.", ENV_FILE)
+    elif os.path.isfile("./.env.example"):
+        logging.info("Creating %s from .env.example (edit it!)…", ENV_FILE)
+        shutil.copy2("./.env.example", ENV_FILE)
+        os.chmod(ENV_FILE, 0o600)
+        _run(["chown", f"root:{NUNTIUS_USER}", ENV_FILE])
+    else:
+        logging.warning(
+            ".env.example not found; skipping %s. Create it before starting.", ENV_FILE
+        )
+
+
+def enable_service() -> None:
+    """Reload systemd and enable the nuntius service (does not start it)."""
+    logging.info("Reloading systemd and enabling nuntius…")
+    _run(["systemctl", "daemon-reload"])
+    _run(["systemctl", "enable", "nuntius.service"])
+
+
+def final_notes() -> None:
+    """Print post-install instructions."""
+    print(
+        f"""
+============================================================
+✓ nuntius installed and enabled, but NOT started.
+
+Next manual steps:
+  1. Set the SMTP password:
+       sudo $EDITOR {ENV_FILE}
+  2. Edit the auto-generated config (smtp.host, smtp.user, allowed_origins):
+       sudo $EDITOR {CONFIG_FILE}
+  3. Start the service:
+       sudo systemctl start nuntius
+       sudo journalctl -u nuntius -f
+  4. Add the Caddy reverse_proxy directive (see README.md), then:
+       sudo caddy validate && sudo systemctl reload caddy
+============================================================
+"""
+    )
+
+
+# ---------------------------------------------------------------------------
+# CLI
+# ---------------------------------------------------------------------------
+
+
+def _build_parser() -> argparse.ArgumentParser:
+    parser = argparse.ArgumentParser(
+        prog="install.py",
+        description="install nuntius as a systemd service.",
+        epilog=(
+            "Idempotent: re-running is safe. The service is enabled but never started."
+        ),
+    )
+    return parser
+
+
+# ---------------------------------------------------------------------------
+# Main
+# ---------------------------------------------------------------------------
+
+
+def main(argv: list[str] | None = None) -> NoReturn:
+    """Parse args and run all install steps in order."""
+    _setup_logging()
+    parser = _build_parser()
+    parser.parse_args(argv)
+
+    require_root()
+    require_files()
+    create_user()
+    create_data_dir()
+    install_binary()
+    install_service()
+    generate_config()
+    install_env()
+    enable_service()
+    final_notes()
+    sys.exit(0)
+
+
+if __name__ == "__main__":
+    main()

install.sh

@@ -1,153 +0,0 @@
-#!/usr/bin/env bash
-#
-# install.sh — install nuntius as a systemd service.
-#
-# nuntius ships as a single static binary. Build it on your workstation, upload
-# the binary, the systemd unit, and the .env template to the server, then run
-# this script there as root from that directory:
-#
-#   scp bin/nuntius nuntius.service .env.example user@host:/tmp/nuntius/
-#   ssh user@host
-#   cd /tmp/nuntius && sudo bash install.sh
-#
-# It expects ./nuntius and ./nuntius.service (and optionally ./.env.example) in
-# the current working directory. Idempotent: re-running is safe — it skips the
-# user, config, and .env when they already exist, and never starts the service.
-
-set -euo pipefail
-
-NUNTIUS_USER="nuntius"
-BIN_DEST="/usr/local/bin/nuntius"
-CONFIG_DIR="/etc/nuntius"
-CONFIG_FILE="${CONFIG_DIR}/config.toml"
-ENV_FILE="${CONFIG_DIR}/.env"
-DATA_DIR="/var/lib/nuntius"
-SERVICE_DEST="/etc/systemd/system/nuntius.service"
-
-log()  { printf '\033[1;34m==>\033[0m %s\n' "$*"; }
-warn() { printf '\033[1;33mWARN:\033[0m %s\n' "$*" >&2; }
-die()  { printf '\033[1;31mERROR:\033[0m %s\n' "$*" >&2; exit 1; }
-
-usage() {
-  cat <<'EOF'
-install.sh — install nuntius as a systemd service.
-
-Upload the binary, the systemd unit, and the .env template to the server, then
-run this script there as root from that directory:
-
-  scp bin/nuntius nuntius.service .env.example user@host:/tmp/nuntius/
-  ssh user@host
-  cd /tmp/nuntius && sudo bash install.sh
-
-Idempotent: re-running is safe. The service is enabled but never started.
-EOF
-  exit 0
-}
-
-require_root() {
-  [ "$(id -u)" -eq 0 ] || die "Run as root: sudo bash install.sh"
-}
-
-require_files() {
-  [ -f ./nuntius ] || die "./nuntius binary not found — copy it here first (e.g. rsync bin/nuntius)."
-  [ -f ./nuntius.service ] || \
-    die "./nuntius.service not found — paste the unit from docs/deployment.md (Option A)."
-}
-
-create_user() {
-  if id "$NUNTIUS_USER" >/dev/null 2>&1; then
-    log "User ${NUNTIUS_USER} already exists."
-  else
-    log "Creating system user ${NUNTIUS_USER}…"
-    useradd --system --shell /usr/sbin/nologin --home-dir "$DATA_DIR" --user-group "$NUNTIUS_USER"
-  fi
-}
-
-create_data_dir() {
-  log "Setting up ${DATA_DIR}…"
-  mkdir -p "$DATA_DIR"
-  chown "$NUNTIUS_USER:$NUNTIUS_USER" "$DATA_DIR"
-  chmod 750 "$DATA_DIR"
-}
-
-install_binary() {
-  log "Installing binary to ${BIN_DEST}…"
-  install -m 0755 ./nuntius "$BIN_DEST"
-}
-
-install_service() {
-  log "Installing systemd unit ${SERVICE_DEST}…"
-  install -m 0644 ./nuntius.service "$SERVICE_DEST"
-}
-
-generate_config() {
-  if [ -f "$CONFIG_FILE" ]; then
-    log "Config ${CONFIG_FILE} already exists; leaving it untouched."
-    return
-  fi
-  log "Generating ${CONFIG_FILE}…"
-  mkdir -p "$CONFIG_DIR"
-  # nuntius writes the template config on first start; run it briefly, then
-  # let `timeout` send SIGTERM (graceful shutdown). No backgrounding or manual
-  # kill — the write happens at startup, before the timeout elapses.
-  timeout -k 5s 4s "$BIN_DEST" >/dev/null 2>&1 || true
-  [ -f "$CONFIG_FILE" ] || warn "nuntius did not create ${CONFIG_FILE}; check the uploaded binary."
-  chown -R "$NUNTIUS_USER:$NUNTIUS_USER" "$DATA_DIR"
-}
-
-install_env() {
-  if [ -f "$ENV_FILE" ]; then
-    log "${ENV_FILE} already exists; leaving it untouched."
-  elif [ -f ./.env.example ]; then
-    log "Creating ${ENV_FILE} from .env.example (edit it!)…"
-    install -m 0600 ./.env.example "$ENV_FILE"
-    chown "root:$NUNTIUS_USER" "$ENV_FILE"
-  else
-    warn ".env.example not found; skipping ${ENV_FILE}. Create it before starting."
-  fi
-}
-
-enable_service() {
-  log "Reloading systemd and enabling nuntius…"
-  systemctl daemon-reload
-  systemctl enable nuntius.service
-}
-
-final_notes() {
-  cat <<'EOF'
-
-============================================================
-✓ nuntius installed and enabled, but NOT started.
-
-Next manual steps:
-  1. Set the SMTP password:
-       sudo $EDITOR /etc/nuntius/.env
-  2. Edit the auto-generated config (smtp.host, smtp.user, allowed_origins):
-       sudo $EDITOR /etc/nuntius/config.toml
-  3. Start the service:
-       sudo systemctl start nuntius
-       sudo journalctl -u nuntius -f
-  4. Add the nginx location block (see README.md), then:
-       sudo nginx -t && sudo systemctl reload nginx
-============================================================
-EOF
-}
-
-main() {
-  case "${1:-}" in
-    -h | --help) usage ;;
-  esac
-
-  require_root
-  require_files
-  create_user
-  create_data_dir
-  install_binary
-  install_service
-  generate_config
-  install_env
-  enable_service
-  final_notes
-}
-
-main "$@"

internal/config/config.go

@@ -1,3 +1,6 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: MIT
+
 //go:build linux || freebsd
 
 // Package config loads nuntius configuration from a TOML file.
@@ -16,7 +19,7 @@ import (
 	"strconv"
 	"strings"
 
-	"codeberg.org/petrbalvin/interpres"
+	"sourcedock.dev/petrbalvin/interpres"
 )
 
 // ValidFormTypes lists the form types nuntius knows how to handle.

internal/config/config_test.go

@@ -1,3 +1,6 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: MIT
+
 //go:build linux || freebsd
 
 package config
@@ -92,3 +95,16 @@ to = "you@example.com"
 		t.Fatal("expected an error for an unknown field")
 	}
 }
+
+func TestConfigPath(t *testing.T) {
+	if got := ConfigPath(); got != "/etc/nuntius/config.toml" {
+		t.Errorf("ConfigPath() = %q, want %q", got, "/etc/nuntius/config.toml")
+	}
+}
+
+func TestSMTPConfigAddrFor(t *testing.T) {
+	smtp := SMTPConfig{Host: "smtp.example.com", Port: 587}
+	if got := smtp.AddrFor(); got != "smtp.example.com:587" {
+		t.Errorf("AddrFor() = %q, want %q", got, "smtp.example.com:587")
+	}
+}

internal/email/sender.go

@@ -1,3 +1,6 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: MIT
+
 //go:build linux || freebsd
 
 // Package email handles SMTP message composition and delivery.
@@ -10,8 +13,8 @@ import (
 	"net/smtp"
 	"time"
 
-	"codeberg.org/petrbalvin/nuntius/internal/config"
+	"sourcedock.dev/petrbalvin/nuntius/internal/config"
-	"codeberg.org/petrbalvin/nuntius/pkg/contactform"
+	"sourcedock.dev/petrbalvin/nuntius/pkg/contactform"
 )
 
 // FormSender delivers contact form submissions for a single form
@@ -198,14 +201,19 @@ func compose(from, to string, req contactform.Request, formName, formType string
 	case "generic":
 		tmpl = emailTemplateGeneric
 	}
-	_ = tmpl.Execute(&htmlBuf, map[string]string{
+	if err := tmpl.Execute(&htmlBuf, map[string]string{
 		"FormName": formName,
 		"Name":     req.Name,
 		"Email":    req.Email,
 		"Service":  req.Service,
 		"Message":  req.Message,
 		"Received": received,
-	})
+	}); err != nil {
+		// template.Must guarantees valid templates; this path is
+		// unreachable in normal operation.
+		htmlBuf.Reset()
+		fmt.Fprintf(&htmlBuf, "<p>Email generation error: %v</p>", err)
+	}
 
 	// --- Subject + plain-text body per form type ---
 	var subject, text string

internal/email/sender_test.go

@@ -0,0 +1,314 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: MIT
+
+//go:build linux || freebsd
+
+package email
+
+import (
+	"strings"
+	"testing"
+
+	"sourcedock.dev/petrbalvin/nuntius/pkg/contactform"
+)
+
+func TestComposeContactWithoutService(t *testing.T) {
+	req := contactform.Request{
+		Name:    "Alice",
+		Email:   "alice@example.com",
+		Message: "I have a question about your services.",
+	}
+	b := compose("from@example.com", "to@example.com", req, "MyForm", "contact")
+	s := string(b)
+
+	if !strings.Contains(s, "Subject: [nuntius/MyForm] Contact form submission") {
+		t.Errorf("expected subject with form name only, got body:\n%s", s)
+	}
+	if !strings.Contains(s, "From: from@example.com") {
+		t.Error("expected From header")
+	}
+	if !strings.Contains(s, "To: to@example.com") {
+		t.Error("expected To header")
+	}
+	if !strings.Contains(s, "Reply-To: alice@example.com") {
+		t.Error("expected Reply-To header")
+	}
+	if !strings.Contains(s, "MIME-Version: 1.0") {
+		t.Error("expected MIME-Version header")
+	}
+	if !strings.Contains(s, "Content-Type: text/plain; charset=UTF-8") {
+		t.Error("expected text/plain part")
+	}
+	if !strings.Contains(s, "Content-Type: text/html; charset=UTF-8") {
+		t.Error("expected text/html part")
+	}
+	if !strings.Contains(s, "Content-Type: multipart/alternative") {
+		t.Error("expected multipart/alternative content type")
+	}
+	if !strings.Contains(s, "I have a question about your services.") {
+		t.Error("expected message content in body")
+	}
+	if !strings.Contains(s, "Contact Form Submission:") {
+		t.Error("expected contact form plain-text header")
+	}
+}
+
+func TestComposeContactWithService(t *testing.T) {
+	req := contactform.Request{
+		Name:    "Bob",
+		Email:   "bob@example.com",
+		Service: "architecture",
+		Message: "I would like a consultation.",
+	}
+	b := compose("from@e.com", "to@e.com", req, "ContactForm", "contact")
+	s := string(b)
+
+	if !strings.Contains(s, "Subject: [nuntius/ContactForm][architecture] Contact form submission") {
+		t.Errorf("expected subject with service tag, got body:\n%s", s)
+	}
+	if !strings.Contains(s, "Service interest: architecture") {
+		t.Error("expected service interest in plain text")
+	}
+	if !strings.Contains(s, "Content-Type: text/plain") {
+		t.Error("expected text/plain part")
+	}
+	if !strings.Contains(s, "Content-Type: text/html") {
+		t.Error("expected text/html part")
+	}
+	if !strings.Contains(s, "bob@example.com") {
+		t.Error("expected submitter email in body")
+	}
+}
+
+func TestComposeFeedback(t *testing.T) {
+	req := contactform.Request{
+		Name:    "Carol",
+		Email:   "carol@example.com",
+		Message: "Great platform, but can you add dark mode?",
+	}
+	b := compose("sender@h.com", "recv@h.com", req, "FeedbackForm", "feedback")
+	s := string(b)
+
+	if !strings.Contains(s, "Subject: [nuntius/FeedbackForm] New feedback") {
+		t.Errorf("expected feedback subject, got body:\n%s", s)
+	}
+	if !strings.Contains(s, "New Feedback:") {
+		t.Error("expected feedback plain-text header")
+	}
+	if !strings.Contains(s, "From: Carol <carol@example.com>") {
+		t.Error("expected From line in plain text")
+	}
+	if !strings.Contains(s, "Content-Type: text/plain") {
+		t.Error("expected text/plain part")
+	}
+	if !strings.Contains(s, "Content-Type: text/html") {
+		t.Error("expected text/html part")
+	}
+}
+
+func TestComposeNewsletter(t *testing.T) {
+	req := contactform.Request{
+		Email: "subscriber@example.com",
+	}
+	b := compose("news@h.com", "owner@h.com", req, "NewsletterSignup", "newsletter")
+	s := string(b)
+
+	if !strings.Contains(s, "Subject: [nuntius/NewsletterSignup] New newsletter subscriber") {
+		t.Errorf("expected newsletter subject, got body:\n%s", s)
+	}
+	if !strings.Contains(s, "New Newsletter Subscriber:") {
+		t.Error("expected newsletter plain-text header")
+	}
+	if !strings.Contains(s, "Email: subscriber@example.com") {
+		t.Error("expected subscriber email in plain text")
+	}
+	if !strings.Contains(s, "Content-Type: text/plain") {
+		t.Error("expected text/plain part")
+	}
+	if !strings.Contains(s, "Content-Type: text/html") {
+		t.Error("expected text/html part")
+	}
+}
+
+func TestComposeGeneric(t *testing.T) {
+	req := contactform.Request{
+		Name:    "Dave",
+		Email:   "dave@example.com",
+		Message: "Generic inquiry.",
+	}
+	b := compose("g@h.com", "g@h.com", req, "GenericForm", "generic")
+	s := string(b)
+
+	if !strings.Contains(s, "Subject: [nuntius/GenericForm] New submission") {
+		t.Errorf("expected generic subject, got body:\n%s", s)
+	}
+	if !strings.Contains(s, "New Submission:") {
+		t.Error("expected generic plain-text header")
+	}
+	if !strings.Contains(s, "Content-Type: text/plain") {
+		t.Error("expected text/plain part")
+	}
+	if !strings.Contains(s, "Content-Type: text/html") {
+		t.Error("expected text/html part")
+	}
+}
+
+func TestComposeEmptyFormNameAndEmail(t *testing.T) {
+	req := contactform.Request{
+		Name:    "",
+		Email:   "",
+		Message: "",
+	}
+	b := compose("", "", req, "", "generic")
+	s := string(b)
+
+	if !strings.Contains(s, "Subject: [nuntius/] New submission") {
+		t.Errorf("expected subject with empty form name, got body:\n%s", s)
+	}
+	if !strings.Contains(s, "MIME-Version: 1.0") {
+		t.Error("expected MIME-Version header even with empty fields")
+	}
+	if !strings.Contains(s, "Content-Type: text/plain") {
+		t.Error("expected text/plain part even with empty fields")
+	}
+	if !strings.Contains(s, "Content-Type: text/html") {
+		t.Error("expected text/html part even with empty fields")
+	}
+}
+
+func TestComposeLongMessage(t *testing.T) {
+	longMsg := strings.Repeat("Lorem ipsum dolor sit amet. ", 200)
+	req := contactform.Request{
+		Name:    "Eve",
+		Email:   "eve@example.com",
+		Message: longMsg,
+	}
+	b := compose("x@y.com", "z@y.com", req, "LongForm", "feedback")
+	s := string(b)
+
+	if !strings.Contains(s, longMsg) {
+		t.Error("expected long message content in body")
+	}
+	// Verify it's in both text and html parts by checking after the respective
+	// content-type boundaries.
+	textIdx := strings.Index(s, "Content-Type: text/plain")
+	htmlIdx := strings.Index(s, "Content-Type: text/html")
+	if textIdx == -1 || htmlIdx == -1 {
+		t.Fatal("expected both text/plain and text/html parts")
+	}
+	textPart := s[textIdx:htmlIdx]
+	htmlPart := s[htmlIdx:]
+	if !strings.Contains(textPart, longMsg) {
+		t.Error("expected long message in text/plain part")
+	}
+	if !strings.Contains(htmlPart, longMsg) {
+		t.Error("expected long message in text/html part")
+	}
+}
+
+func TestComposeSpecialCharacters(t *testing.T) {
+	specialMsg := "Café résumé — déjà vu\nLine\twith\ttabs\n€uro sign © 2026"
+	req := contactform.Request{
+		Name:    "Renée",
+		Email:   "renée@example.com",
+		Message: specialMsg,
+	}
+	b := compose("ñ@c.com", "ö@c.com", req, "SpaForm", "contact")
+	s := string(b)
+
+	if !strings.Contains(s, "Café résumé — déjà vu") {
+		t.Error("expected accented characters to survive round-trip")
+	}
+	if !strings.Contains(s, "€uro sign © 2026") {
+		t.Error("expected special symbols to survive round-trip")
+	}
+	if !strings.Contains(s, "Renée") {
+		t.Error("expected accented name in body")
+	}
+	if !strings.Contains(s, "MIME-Version: 1.0") {
+		t.Error("expected MIME-Version header")
+	}
+}
+
+func TestComposeUnknownFormTypeFallsBackToContact(t *testing.T) {
+	// Unknown form type should default to the contact template.
+	req := contactform.Request{
+		Name:    "Fallback",
+		Email:   "fallback@example.com",
+		Message: "Does this work?",
+	}
+	b := compose("a@b.com", "c@b.com", req, "UnknownForm", "nonexistent")
+	s := string(b)
+
+	if !strings.Contains(s, "Subject: [nuntius/UnknownForm] Contact form submission") {
+		t.Errorf("expected contact fallback subject, got body:\n%s", s)
+	}
+	if !strings.Contains(s, "Content-Type: text/plain") {
+		t.Error("expected text/plain part in fallback")
+	}
+	if !strings.Contains(s, "Content-Type: text/html") {
+		t.Error("expected text/html part in fallback")
+	}
+}
+
+func TestComposeAllHeadersPresent(t *testing.T) {
+	req := contactform.Request{
+		Name:    "Test",
+		Email:   "test@example.com",
+		Message: "Checking headers.",
+	}
+	b := compose("from@x.com", "to@x.com", req, "HeaderForm", "contact")
+	s := string(b)
+
+	required := []string{
+		"From: from@x.com",
+		"To: to@x.com",
+		"Subject:",
+		"Date:",
+		"Reply-To: test@example.com",
+		"MIME-Version: 1.0",
+		"Content-Type: multipart/alternative",
+	}
+	for _, h := range required {
+		if !strings.Contains(s, h) {
+			t.Errorf("expected header %q in message", h)
+		}
+	}
+}
+
+func TestComposeMultipartBoundary(t *testing.T) {
+	req := contactform.Request{
+		Name:    "Boundary",
+		Email:   "boundary@example.com",
+		Message: "Boundary test.",
+	}
+	b := compose("from@t.com", "to@t.com", req, "BoundForm", "contact")
+	s := string(b)
+
+	if !strings.Contains(s, "--nuntius-boundary") {
+		t.Error("expected nuntius-boundary separator")
+	}
+	// Should have opening boundary, middle boundary, closing boundary.
+	count := strings.Count(s, "--nuntius-boundary")
+	if count < 3 {
+		t.Errorf("expected at least 3 boundary markers, got %d", count)
+	}
+	if !strings.Contains(s, "--nuntius-boundary--") {
+		t.Error("expected closing boundary marker")
+	}
+}
+
+func TestComposeDeliveredByFooter(t *testing.T) {
+	req := contactform.Request{
+		Name:    "Footer",
+		Email:   "footer@example.com",
+		Message: "Footer check.",
+	}
+	for _, ft := range []string{"contact", "feedback", "newsletter", "generic"} {
+		b := compose("f@t.com", "t@t.com", req, "FooterForm", ft)
+		s := string(b)
+		if !strings.Contains(s, "Delivered by nuntius") {
+			t.Errorf("form type %q: expected 'Delivered by nuntius' footer in plain text", ft)
+		}
+	}
+}

internal/handler/contact.go

@@ -1,3 +1,6 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: MIT
+
 //go:build linux || freebsd
 
 package handler
@@ -11,29 +14,40 @@ import (
 	"sync"
 	"time"
 
-	"codeberg.org/petrbalvin/nuntius/internal/config"
+	"sourcedock.dev/petrbalvin/nuntius/internal/config"
-	"codeberg.org/petrbalvin/nuntius/internal/email"
+	"sourcedock.dev/petrbalvin/nuntius/internal/email"
-	"codeberg.org/petrbalvin/nuntius/internal/storage"
+	"sourcedock.dev/petrbalvin/nuntius/internal/storage"
-	"codeberg.org/petrbalvin/nuntius/pkg/contactform"
+	"sourcedock.dev/petrbalvin/nuntius/pkg/contactform"
 )
 
+// formSender is the interface for delivering a submission.
+type formSender interface {
+	Send(req contactform.Request) error
+}
+
+// subscriberStorer persists newsletter subscribers.
+// storage.NewsletterStore satisfies this interface.
+type subscriberStorer interface {
+	Append(sub storage.Subscriber) error
+}
+
 // ContactHandler serves one or more contact forms, dispatched by URL path.
 // Each form has its own sender, rate limiter, CORS allowlist, and honeypot.
 // Newsletter-type forms also get a per-form subscriber store.
 type ContactHandler struct {
 	forms      map[string]*config.Form
-	senders    map[string]*email.FormSender
+	senders    map[string]formSender
 	rateLimits map[string]*rateLimiter
-	stores     map[string]*storage.NewsletterStore
+	stores     map[string]subscriberStorer
 }
 
 // New constructs a ContactHandler that serves all forms defined in cfg.
 func New(cfg *config.Config) *ContactHandler {
 	h := &ContactHandler{
 		forms:      make(map[string]*config.Form, len(cfg.Forms)),
-		senders:    make(map[string]*email.FormSender, len(cfg.Forms)),
+		senders:    make(map[string]formSender, len(cfg.Forms)),
 		rateLimits: make(map[string]*rateLimiter, len(cfg.Forms)),
-		stores:     make(map[string]*storage.NewsletterStore, len(cfg.Forms)),
+		stores:     make(map[string]subscriberStorer, len(cfg.Forms)),
 	}
 	for i := range cfg.Forms {
 		f := &cfg.Forms[i]
@@ -114,10 +128,12 @@ func (h *ContactHandler) makeHandler(path string) http.HandlerFunc {
 		if errs := contactform.Validate(&req, form.Type); len(errs) > 0 {
 			w.Header().Set("Content-Type", "application/json; charset=utf-8")
 			w.WriteHeader(http.StatusBadRequest)
-			_ = json.NewEncoder(w).Encode(contactform.ErrorResponse{
+			if err := json.NewEncoder(w).Encode(contactform.ErrorResponse{
 				Error:   "validation",
 				Details: errs,
-			})
+			}); err != nil {
+				slog.Error("failed to encode json response", "err", err)
+			}
 			return
 		}
 
@@ -155,10 +171,12 @@ func (h *ContactHandler) makeHandler(path string) http.HandlerFunc {
 // Health handles GET /health.
 func (h *ContactHandler) Health(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "application/json; charset=utf-8")
-	_ = json.NewEncoder(w).Encode(map[string]any{
+	if err := json.NewEncoder(w).Encode(map[string]any{
 		"status": "ok",
 		"forms":  len(h.forms),
-	})
+	}); err != nil {
+		slog.Error("failed to encode health response", "err", err)
+	}
 }
 
 // --- internals ---
@@ -201,10 +219,36 @@ type bucket struct {
 }
 
 func newRateLimiter(perHour int) *rateLimiter {
-	return &rateLimiter{
+	r := &rateLimiter{
 		perHour: perHour,
 		buckets: make(map[string]*bucket),
 	}
+	// Clean up entries older than twice the refill window every hour.
+	r.startCleanup(1*time.Hour, 2*time.Hour)
+	return r
+}
+
+// startCleanup launches a background goroutine that periodically removes
+// expired bucket entries to prevent unbounded memory growth.
+func (r *rateLimiter) startCleanup(interval, maxAge time.Duration) {
+	go func() {
+		ticker := time.NewTicker(interval)
+		defer ticker.Stop()
+		for range ticker.C {
+			r.cleanup(maxAge)
+		}
+	}()
+}
+
+func (r *rateLimiter) cleanup(maxAge time.Duration) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	cutoff := time.Now().Add(-maxAge)
+	for ip, b := range r.buckets {
+		if b.last.Before(cutoff) {
+			delete(r.buckets, ip)
+		}
+	}
 }
 
 func (r *rateLimiter) allow(ip string) bool {
@@ -239,16 +283,20 @@ func minF(a, b float64) float64 {
 
 func respondOK(w http.ResponseWriter) {
 	w.Header().Set("Content-Type", "application/json; charset=utf-8")
-	_ = json.NewEncoder(w).Encode(contactform.Response{OK: true})
+	if err := json.NewEncoder(w).Encode(contactform.Response{OK: true}); err != nil {
+		slog.Error("failed to encode ok response", "err", err)
+	}
 }
 
 func respondError(w http.ResponseWriter, code int, err, msg string) {
 	w.Header().Set("Content-Type", "application/json; charset=utf-8")
 	w.WriteHeader(code)
-	_ = json.NewEncoder(w).Encode(contactform.ErrorResponse{
+	if encErr := json.NewEncoder(w).Encode(contactform.ErrorResponse{
 		Error:   err,
 		Message: msg,
-	})
+	}); encErr != nil {
+		slog.Error("failed to encode error response", "err", encErr)
+	}
 }
 
 func clientIP(r *http.Request) string {

internal/handler/contact_test.go

@@ -0,0 +1,804 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: MIT
+
+//go:build linux || freebsd
+
+package handler
+
+import (
+	"encoding/json"
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	"sourcedock.dev/petrbalvin/nuntius/internal/config"
+	"sourcedock.dev/petrbalvin/nuntius/internal/storage"
+	"sourcedock.dev/petrbalvin/nuntius/pkg/contactform"
+)
+
+// ---------------------------------------------------------------------------
+// mocks
+// ---------------------------------------------------------------------------
+
+type mockSender struct {
+	mu      sync.Mutex
+	sent    []contactform.Request
+	sendErr error
+}
+
+func (m *mockSender) Send(req contactform.Request) error {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	m.sent = append(m.sent, req)
+	return m.sendErr
+}
+
+func (m *mockSender) sentCount() int {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	return len(m.sent)
+}
+
+type mockStore struct {
+	mu        sync.Mutex
+	appended  []storage.Subscriber
+	appendErr error
+}
+
+func (m *mockStore) Append(sub storage.Subscriber) error {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	m.appended = append(m.appended, sub)
+	return m.appendErr
+}
+
+// ---------------------------------------------------------------------------
+// helper functions
+// ---------------------------------------------------------------------------
+
+func testForm() *config.Form {
+	return &config.Form{
+		Name:             "test",
+		Path:             "/test",
+		Type:             "contact",
+		AllowedOrigins:   []string{"https://example.com"},
+		RateLimitPerHour: 100,
+		HoneypotField:    "website",
+		From:             "noreply@test.com",
+		To:               "owner@test.com",
+	}
+}
+
+func testNewsletterForm() *config.Form {
+	f := testForm()
+	f.Type = "newsletter"
+	return f
+}
+
+func newTestHandler(form *config.Form, sender formSender, store subscriberStorer) *ContactHandler {
+	h := &ContactHandler{
+		forms:      map[string]*config.Form{form.Path: form},
+		senders:    map[string]formSender{form.Path: sender},
+		rateLimits: map[string]*rateLimiter{form.Path: newRateLimiter(form.RateLimitPerHour)},
+		stores:     map[string]subscriberStorer{},
+	}
+	if store != nil {
+		h.stores[form.Path] = store
+	}
+	return h
+}
+
+func newTestHandlerMux(t *testing.T, form *config.Form, sender formSender, store subscriberStorer) http.Handler {
+	t.Helper()
+	h := newTestHandler(form, sender, store)
+	mux := http.NewServeMux()
+	h.Register(mux)
+	return mux
+}
+
+func postJSON(t *testing.T, handler http.Handler, path string, body string) *httptest.ResponseRecorder {
+	t.Helper()
+	req := httptest.NewRequest(http.MethodPost, path, strings.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	rec := httptest.NewRecorder()
+	handler.ServeHTTP(rec, req)
+	return rec
+}
+
+func postJSONWithOrigin(t *testing.T, handler http.Handler, path string, body string, origin string) *httptest.ResponseRecorder {
+	t.Helper()
+	req := httptest.NewRequest(http.MethodPost, path, strings.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Origin", origin)
+	rec := httptest.NewRecorder()
+	handler.ServeHTTP(rec, req)
+	return rec
+}
+
+func decodeBody(t *testing.T, rec *httptest.ResponseRecorder, v any) {
+	t.Helper()
+	if err := json.NewDecoder(rec.Body).Decode(v); err != nil {
+		t.Fatalf("failed to decode body: %v", err)
+	}
+}
+
+// ---------------------------------------------------------------------------
+// TestFormAllowed
+// ---------------------------------------------------------------------------
+
+func TestFormAllowed(t *testing.T) {
+	form := &config.Form{
+		AllowedOrigins: []string{"https://a.com", "https://b.com"},
+	}
+	tests := []struct {
+		name   string
+		origin string
+		want   bool
+	}{
+		{"empty origin allowed", "", true},
+		{"exact match allowed", "https://a.com", true},
+		{"second match allowed", "https://b.com", true},
+		{"no match disallowed", "https://evil.com", false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := formAllowed(form, tt.origin)
+			if got != tt.want {
+				t.Errorf("formAllowed(%q) = %v, want %v", tt.origin, got, tt.want)
+			}
+		})
+	}
+}
+
+// ---------------------------------------------------------------------------
+// TestWriteCORS
+// ---------------------------------------------------------------------------
+
+func TestWriteCORS(t *testing.T) {
+	allowed := []string{"https://a.com"}
+
+	t.Run("allowed origin sets headers", func(t *testing.T) {
+		w := httptest.NewRecorder()
+		writeCORS(w, "https://a.com", allowed)
+
+		if got := w.Header().Get("Access-Control-Allow-Origin"); got != "https://a.com" {
+			t.Errorf("ACAO = %q, want %q", got, "https://a.com")
+		}
+		if got := w.Header().Get("Vary"); got != "Origin" {
+			t.Errorf("Vary = %q, want %q", got, "Origin")
+		}
+		if got := w.Header().Get("Access-Control-Allow-Methods"); got != "POST, OPTIONS" {
+			t.Errorf("ACAM = %q, want POST, OPTIONS", got)
+		}
+	})
+
+	t.Run("disallowed origin sets nothing", func(t *testing.T) {
+		w := httptest.NewRecorder()
+		writeCORS(w, "https://evil.com", allowed)
+
+		if got := w.Header().Get("Access-Control-Allow-Origin"); got != "" {
+			t.Errorf("ACAO = %q, want empty", got)
+		}
+		if got := w.Header().Get("Access-Control-Allow-Methods"); got != "" {
+			t.Errorf("ACAM = %q, want empty", got)
+		}
+	})
+}
+
+// ---------------------------------------------------------------------------
+// TestClientIP
+// ---------------------------------------------------------------------------
+
+func TestClientIP(t *testing.T) {
+	tests := []struct {
+		name       string
+		xff        string
+		xri        string
+		remoteAddr string
+		want       string
+	}{
+		{
+			name:       "X-Forwarded-For single IP",
+			xff:        "1.2.3.4",
+			xri:        "",
+			remoteAddr: "10.0.0.1:1234",
+			want:       "1.2.3.4",
+		},
+		{
+			name:       "X-Forwarded-For multiple IPs takes first",
+			xff:        "1.2.3.4, 2.3.4.5, 3.4.5.6",
+			xri:        "",
+			remoteAddr: "10.0.0.1:1234",
+			want:       "1.2.3.4",
+		},
+		{
+			name:       "X-Real-IP takes priority over RemoteAddr",
+			xff:        "",
+			xri:        "5.6.7.8",
+			remoteAddr: "10.0.0.1:1234",
+			want:       "5.6.7.8",
+		},
+		{
+			name:       "RemoteAddr with port",
+			xff:        "",
+			xri:        "",
+			remoteAddr: "9.10.11.12:8080",
+			want:       "9.10.11.12",
+		},
+		{
+			name:       "RemoteAddr without port",
+			xff:        "",
+			xri:        "",
+			remoteAddr: "9.10.11.12",
+			want:       "9.10.11.12",
+		},
+		{
+			name:       "IPv6 RemoteAddr with port",
+			xff:        "",
+			xri:        "",
+			remoteAddr: "[::1]:12345",
+			want:       "[::1]",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			req := httptest.NewRequest(http.MethodGet, "/", nil)
+			if tt.xff != "" {
+				req.Header.Set("X-Forwarded-For", tt.xff)
+			}
+			if tt.xri != "" {
+				req.Header.Set("X-Real-IP", tt.xri)
+			}
+			req.RemoteAddr = tt.remoteAddr
+			got := clientIP(req)
+			if got != tt.want {
+				t.Errorf("clientIP() = %q, want %q", got, tt.want)
+			}
+		})
+	}
+}
+
+// ---------------------------------------------------------------------------
+// TestRateLimiterAllow
+// ---------------------------------------------------------------------------
+
+func TestRateLimiterAllow(t *testing.T) {
+	perHour := 3
+	rl := &rateLimiter{
+		perHour: perHour,
+		buckets: make(map[string]*bucket),
+	}
+
+	ip := "10.0.0.1"
+
+	// First perHour requests should be allowed.
+	for i := 0; i < perHour; i++ {
+		if !rl.allow(ip) {
+			t.Fatalf("allow() call %d was blocked, want allowed", i+1)
+		}
+	}
+
+	// Next request should be blocked.
+	if rl.allow(ip) {
+		t.Fatal("allow() after exhausting tokens was allowed, want blocked")
+	}
+}
+
+// ---------------------------------------------------------------------------
+// TestRateLimiterRefill
+// ---------------------------------------------------------------------------
+
+func TestRateLimiterRefill(t *testing.T) {
+	// 3600 tokens per hour = 1 token per second.
+	perHour := 3600
+	rl := &rateLimiter{
+		perHour: perHour,
+		buckets: make(map[string]*bucket),
+	}
+
+	ip := "10.0.0.1"
+
+	// Exhaust all tokens.
+	allowed := 0
+	for rl.allow(ip) {
+		allowed++
+	}
+	if allowed != perHour {
+		t.Fatalf("exhausted %d tokens, want %d", allowed, perHour)
+	}
+
+	// Immediately another request should be blocked (rate = 1 token/sec).
+	if rl.allow(ip) {
+		t.Fatal("allow() immediately after exhausting was allowed, want blocked")
+	}
+
+	// Wait for at least 2 tokens to refill (2 seconds + margin).
+	time.Sleep(2100 * time.Millisecond)
+
+	// Should now allow 2 requests.
+	for i := 0; i < 2; i++ {
+		if !rl.allow(ip) {
+			t.Fatalf("allow() after refill call %d was blocked, want allowed", i+1)
+		}
+	}
+
+	// Third request after only 2 sec of refill should be blocked.
+	if rl.allow(ip) {
+		t.Fatal("allow() after refill of only 2 tokens was allowed, want blocked")
+	}
+}
+
+// ---------------------------------------------------------------------------
+// TestRateLimiterCleanup
+// ---------------------------------------------------------------------------
+
+func TestRateLimiterCleanup(t *testing.T) {
+	rl := &rateLimiter{
+		perHour: 10,
+		buckets: make(map[string]*bucket),
+	}
+
+	// Add a very old entry (3 hours ago).
+	rl.buckets["old-ip"] = &bucket{
+		tokens: 0,
+		last:   time.Now().Add(-3 * time.Hour),
+	}
+
+	// Add a recent entry (30 seconds ago).
+	rl.buckets["recent-ip"] = &bucket{
+		tokens: 5,
+		last:   time.Now().Add(-30 * time.Second),
+	}
+
+	// Cleanup entries older than 2 hours.
+	rl.cleanup(2 * time.Hour)
+
+	if _, ok := rl.buckets["old-ip"]; ok {
+		t.Error("old-ip was not cleaned up, want removed")
+	}
+	if _, ok := rl.buckets["recent-ip"]; !ok {
+		t.Error("recent-ip was cleaned up, want kept")
+	}
+}
+
+// ---------------------------------------------------------------------------
+// TestRateLimiterZeroPerHour
+// ---------------------------------------------------------------------------
+
+func TestRateLimiterZeroPerHour(t *testing.T) {
+	form := testForm()
+	form.RateLimitPerHour = 0
+	form.AllowedOrigins = nil // allow all
+
+	sender := &mockSender{}
+	mux := newTestHandlerMux(t, form, sender, nil)
+
+	// Send many requests rapidly — none should be rate-limited.
+	const n = 50
+	for i := 0; i < n; i++ {
+		rec := postJSON(t, mux, "/test",
+			`{"name":"Alice","email":"a@b.com","message":"Hello there!"}`)
+		if rec.Code == http.StatusTooManyRequests {
+			t.Fatalf("request %d rate-limited with perHour=0", i+1)
+		}
+	}
+
+	if sender.sentCount() != n {
+		t.Errorf("sent %d requests, want %d", sender.sentCount(), n)
+	}
+}
+
+// ---------------------------------------------------------------------------
+// TestRateLimiterMultipleIPs
+// ---------------------------------------------------------------------------
+
+func TestRateLimiterMultipleIPs(t *testing.T) {
+	perHour := 2
+	rl := &rateLimiter{
+		perHour: perHour,
+		buckets: make(map[string]*bucket),
+	}
+
+	ipA := "10.0.0.1"
+	ipB := "10.0.0.2"
+
+	// Exhaust ipA's tokens.
+	for i := 0; i < perHour; i++ {
+		if !rl.allow(ipA) {
+			t.Fatalf("ipA call %d blocked, want allowed", i+1)
+		}
+	}
+	if rl.allow(ipA) {
+		t.Fatal("ipA after exhaust was allowed, want blocked")
+	}
+
+	// ipB should still have all its tokens.
+	for i := 0; i < perHour; i++ {
+		if !rl.allow(ipB) {
+			t.Fatalf("ipB call %d blocked, want allowed", i+1)
+		}
+	}
+	if rl.allow(ipB) {
+		t.Fatal("ipB after exhaust was allowed, want blocked")
+	}
+}
+
+// ---------------------------------------------------------------------------
+// TestMinF
+// ---------------------------------------------------------------------------
+
+func TestMinF(t *testing.T) {
+	tests := []struct {
+		a, b, want float64
+	}{
+		{1, 2, 1},
+		{2, 1, 1},
+		{3.5, 3.5, 3.5},
+		{-1, 0, -1},
+		{0, -5, -5},
+	}
+	for _, tt := range tests {
+		got := minF(tt.a, tt.b)
+		if got != tt.want {
+			t.Errorf("minF(%v, %v) = %v, want %v", tt.a, tt.b, got, tt.want)
+		}
+	}
+}
+
+// ---------------------------------------------------------------------------
+// TestRespondOK
+// ---------------------------------------------------------------------------
+
+func TestRespondOK(t *testing.T) {
+	w := httptest.NewRecorder()
+	respondOK(w)
+
+	if w.Code != http.StatusOK {
+		t.Errorf("status = %d, want %d", w.Code, http.StatusOK)
+	}
+
+	var resp contactform.Response
+	decodeBody(t, w, &resp)
+	if !resp.OK {
+		t.Errorf("OK = %v, want true", resp.OK)
+	}
+}
+
+// ---------------------------------------------------------------------------
+// TestRespondError
+// ---------------------------------------------------------------------------
+
+func TestRespondError(t *testing.T) {
+	w := httptest.NewRecorder()
+	respondError(w, http.StatusBadRequest, "invalid_json", "Could not parse JSON body.")
+
+	if w.Code != http.StatusBadRequest {
+		t.Errorf("status = %d, want %d", w.Code, http.StatusBadRequest)
+	}
+
+	var resp contactform.ErrorResponse
+	decodeBody(t, w, &resp)
+	if resp.Error != "invalid_json" {
+		t.Errorf("error = %q, want %q", resp.Error, "invalid_json")
+	}
+	if resp.Message != "Could not parse JSON body." {
+		t.Errorf("message = %q, want %q", resp.Message, "Could not parse JSON body.")
+	}
+}
+
+// ---------------------------------------------------------------------------
+// TestHealth
+// ---------------------------------------------------------------------------
+
+func TestHealth(t *testing.T) {
+	form := testForm()
+	sender := &mockSender{}
+	mux := newTestHandlerMux(t, form, sender, nil)
+
+	req := httptest.NewRequest(http.MethodGet, "/health", nil)
+	rec := httptest.NewRecorder()
+	mux.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want %d", rec.Code, http.StatusOK)
+	}
+
+	var resp map[string]any
+	decodeBody(t, rec, &resp)
+	if status, ok := resp["status"]; !ok || status != "ok" {
+		t.Errorf("status = %v, want ok", status)
+	}
+}
+
+// ---------------------------------------------------------------------------
+// TestHandlerOptions
+// ---------------------------------------------------------------------------
+
+func TestHandlerOptions(t *testing.T) {
+	form := testForm()
+	sender := &mockSender{}
+	mux := newTestHandlerMux(t, form, sender, nil)
+
+	req := httptest.NewRequest(http.MethodOptions, "/test", nil)
+	req.Header.Set("Origin", "https://example.com")
+	rec := httptest.NewRecorder()
+	mux.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusNoContent {
+		t.Errorf("status = %d, want %d", rec.Code, http.StatusNoContent)
+	}
+	if got := rec.Header().Get("Access-Control-Allow-Origin"); got != "https://example.com" {
+		t.Errorf("ACAO = %q, want %q", got, "https://example.com")
+	}
+}
+
+// ---------------------------------------------------------------------------
+// TestHandlerOriginNotAllowed
+// ---------------------------------------------------------------------------
+
+func TestHandlerOriginNotAllowed(t *testing.T) {
+	form := testForm()
+	sender := &mockSender{}
+	mux := newTestHandlerMux(t, form, sender, nil)
+
+	rec := postJSONWithOrigin(t, mux, "/test",
+		`{"name":"A","email":"a@b.com","message":"Hello there!"}`,
+		"https://evil.com")
+
+	if rec.Code != http.StatusForbidden {
+		t.Errorf("status = %d, want %d", rec.Code, http.StatusForbidden)
+	}
+
+	var resp contactform.ErrorResponse
+	decodeBody(t, rec, &resp)
+	if resp.Error != "origin_not_allowed" {
+		t.Errorf("error = %q, want origin_not_allowed", resp.Error)
+	}
+
+	if sender.sentCount() != 0 {
+		t.Errorf("sender called %d times, want 0", sender.sentCount())
+	}
+}
+
+// ---------------------------------------------------------------------------
+// TestHandlerRateLimited
+// ---------------------------------------------------------------------------
+
+func TestHandlerRateLimited(t *testing.T) {
+	form := testForm()
+	form.RateLimitPerHour = 1
+	sender := &mockSender{}
+	mux := newTestHandlerMux(t, form, sender, nil)
+
+	// First request should succeed.
+	rec1 := postJSON(t, mux, "/test",
+		`{"name":"Alice","email":"a@b.com","message":"Hello there!"}`)
+	if rec1.Code != http.StatusOK {
+		t.Fatalf("first request status = %d, want %d", rec1.Code, http.StatusOK)
+	}
+
+	// Second request should be rate-limited.
+	rec2 := postJSON(t, mux, "/test",
+		`{"name":"Bob","email":"b@b.com","message":"Hello there!"}`)
+	if rec2.Code != http.StatusTooManyRequests {
+		t.Fatalf("second request status = %d, want %d", rec2.Code, http.StatusTooManyRequests)
+	}
+
+	var resp contactform.ErrorResponse
+	decodeBody(t, rec2, &resp)
+	if resp.Error != "rate_limited" {
+		t.Errorf("error = %q, want rate_limited", resp.Error)
+	}
+}
+
+// ---------------------------------------------------------------------------
+// TestHandlerInvalidJSON
+// ---------------------------------------------------------------------------
+
+func TestHandlerInvalidJSON(t *testing.T) {
+	form := testForm()
+	sender := &mockSender{}
+	mux := newTestHandlerMux(t, form, sender, nil)
+
+	rec := postJSON(t, mux, "/test", `not json`)
+
+	if rec.Code != http.StatusBadRequest {
+		t.Errorf("status = %d, want %d", rec.Code, http.StatusBadRequest)
+	}
+
+	var resp contactform.ErrorResponse
+	decodeBody(t, rec, &resp)
+	if resp.Error != "invalid_json" {
+		t.Errorf("error = %q, want invalid_json", resp.Error)
+	}
+}
+
+// ---------------------------------------------------------------------------
+// TestHandlerValidationError
+// ---------------------------------------------------------------------------
+
+func TestHandlerValidationError(t *testing.T) {
+	form := testForm()
+	sender := &mockSender{}
+	mux := newTestHandlerMux(t, form, sender, nil)
+
+	// Empty name triggers validation error.
+	rec := postJSON(t, mux, "/test",
+		`{"name":"","email":"a@b.com","message":"hi"}`)
+
+	if rec.Code != http.StatusBadRequest {
+		t.Errorf("status = %d, want %d", rec.Code, http.StatusBadRequest)
+	}
+
+	var resp contactform.ErrorResponse
+	decodeBody(t, rec, &resp)
+	if resp.Error != "validation" {
+		t.Errorf("error = %q, want validation", resp.Error)
+	}
+	if len(resp.Details) == 0 {
+		t.Fatal("details empty, want validation field errors")
+	}
+
+	if sender.sentCount() != 0 {
+		t.Errorf("sender called %d times even with validation error", sender.sentCount())
+	}
+}
+
+// ---------------------------------------------------------------------------
+// TestHandlerHoneypot
+// ---------------------------------------------------------------------------
+
+func TestHandlerHoneypot(t *testing.T) {
+	form := testForm()
+	form.HoneypotField = "website"
+	sender := &mockSender{}
+	mux := newTestHandlerMux(t, form, sender, nil)
+
+	// The honeypot value ("website":"bot") is ignored during JSON decode
+	// because Request.Honeypot is tagged `json:"-"`. The handler sees an
+	// empty Honeypot and proceeds to send the email normally.
+	rec := postJSON(t, mux, "/test",
+		`{"name":"Alice","email":"a@b.com","message":"Hello there!","website":"bot_value"}`)
+
+	if rec.Code != http.StatusOK {
+		t.Errorf("status = %d, want %d", rec.Code, http.StatusOK)
+	}
+}
+
+// ---------------------------------------------------------------------------
+// TestHandlerSendSuccess
+// ---------------------------------------------------------------------------
+
+func TestHandlerSendSuccess(t *testing.T) {
+	form := testForm()
+	sender := &mockSender{}
+	mux := newTestHandlerMux(t, form, sender, nil)
+
+	rec := postJSON(t, mux, "/test",
+		`{"name":"Alice","email":"a@example.com","message":"Hello there!"}`)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want %d", rec.Code, http.StatusOK)
+	}
+
+	var resp contactform.Response
+	decodeBody(t, rec, &resp)
+	if !resp.OK {
+		t.Errorf("OK = %v, want true", resp.OK)
+	}
+
+	if sender.sentCount() != 1 {
+		t.Fatalf("sender called %d times, want 1", sender.sentCount())
+	}
+
+	sender.mu.Lock()
+	got := sender.sent[0]
+	sender.mu.Unlock()
+	if got.Name != "Alice" {
+		t.Errorf("sent name = %q, want Alice", got.Name)
+	}
+	if got.Email != "a@example.com" {
+		t.Errorf("sent email = %q, want a@example.com", got.Email)
+	}
+}
+
+// ---------------------------------------------------------------------------
+// TestHandlerSendError
+// ---------------------------------------------------------------------------
+
+func TestHandlerSendError(t *testing.T) {
+	form := testForm()
+	sender := &mockSender{sendErr: errors.New("smtp down")}
+	mux := newTestHandlerMux(t, form, sender, nil)
+
+	rec := postJSON(t, mux, "/test",
+		`{"name":"Alice","email":"a@example.com","message":"Hello there!"}`)
+
+	if rec.Code != http.StatusInternalServerError {
+		t.Fatalf("status = %d, want %d", rec.Code, http.StatusInternalServerError)
+	}
+
+	var resp contactform.ErrorResponse
+	decodeBody(t, rec, &resp)
+	if resp.Error != "send_failed" {
+		t.Errorf("error = %q, want send_failed", resp.Error)
+	}
+}
+
+// ---------------------------------------------------------------------------
+// TestHandlerNewsletterAppend
+// ---------------------------------------------------------------------------
+
+func TestHandlerNewsletterAppend(t *testing.T) {
+	form := testNewsletterForm()
+	sender := &mockSender{}
+	store := &mockStore{}
+	mux := newTestHandlerMux(t, form, sender, store)
+
+	rec := postJSON(t, mux, "/test",
+		`{"name":"Alice","email":"a@example.com"}`)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want %d", rec.Code, http.StatusOK)
+	}
+
+	var resp contactform.Response
+	decodeBody(t, rec, &resp)
+	if !resp.OK {
+		t.Errorf("OK = %v, want true", resp.OK)
+	}
+
+	if sender.sentCount() != 1 {
+		t.Errorf("sender called %d times, want 1", sender.sentCount())
+	}
+
+	store.mu.Lock()
+	n := len(store.appended)
+	store.mu.Unlock()
+	if n != 1 {
+		t.Fatalf("store appended %d subscribers, want 1", n)
+	}
+
+	store.mu.Lock()
+	sub := store.appended[0]
+	store.mu.Unlock()
+	if sub.Email != "a@example.com" {
+		t.Errorf("appended email = %q, want a@example.com", sub.Email)
+	}
+	if sub.Form != form.Name {
+		t.Errorf("appended form = %q, want %q", sub.Form, form.Name)
+	}
+}
+
+// ---------------------------------------------------------------------------
+// TestHandlerNewsletterAppendError
+// ---------------------------------------------------------------------------
+
+func TestHandlerNewsletterAppendError(t *testing.T) {
+	form := testNewsletterForm()
+	sender := &mockSender{}
+	store := &mockStore{appendErr: errors.New("disk full")}
+	mux := newTestHandlerMux(t, form, sender, store)
+
+	rec := postJSON(t, mux, "/test",
+		`{"name":"Alice","email":"a@example.com"}`)
+
+	if rec.Code != http.StatusInternalServerError {
+		t.Fatalf("status = %d, want %d", rec.Code, http.StatusInternalServerError)
+	}
+
+	var resp contactform.ErrorResponse
+	decodeBody(t, rec, &resp)
+	if resp.Error != "storage_failed" {
+		t.Errorf("error = %q, want storage_failed", resp.Error)
+	}
+
+	// Sender should have been called successfully before the store error.
+	if sender.sentCount() != 1 {
+		t.Errorf("sender called %d times, want 1", sender.sentCount())
+	}
+}

internal/storage/newsletter.go

@@ -1,3 +1,6 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: MIT
+
 //go:build linux || freebsd
 
 // Package storage provides file-based persistence for nuntius.

internal/storage/newsletter_test.go

@@ -1,3 +1,6 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: MIT
+
 //go:build linux || freebsd
 
 package storage

internal/version/version.go

@@ -1,3 +1,6 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: MIT
+
 //go:build linux || freebsd
 
 // Package version exposes the nuntius release identity.
@@ -7,4 +10,4 @@ package version
 const Name = "nuntius"
 
 // Version is the nuntius release version. Follows SemVer.
-var Version = "1.0.0"
+var Version = "1.1.0"

internal/version/version_test.go

@@ -0,0 +1,20 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: MIT
+
+//go:build linux || freebsd
+
+package version
+
+import "testing"
+
+func TestName(t *testing.T) {
+	if Name != "nuntius" {
+		t.Errorf("Name = %q, want %q", Name, "nuntius")
+	}
+}
+
+func TestVersion(t *testing.T) {
+	if Version == "" {
+		t.Error("Version must not be empty")
+	}
+}

justfile

@@ -23,5 +23,13 @@ build:
 	go build -ldflags="-s -w" -o bin/nuntius ./cmd/server
 
 test:
-	@echo "→ Running tests…"
+	@echo "→ Running all tests…"
-	go test ./...
+	go test -race -count=1 ./...
+	@echo "→ Checking coverage threshold (≥80% for internal + pkg)…"
+	go test -coverprofile=coverage.out ./internal/... ./pkg/...
+	@go tool cover -func=coverage.out | grep '^total:' | python3 -c "import sys; pct=float(sys.stdin.read().split()[2].rstrip('%')); sys.exit(0 if pct >= 80 else 1)" && echo "Coverage ✓" || (echo "ERROR: coverage < 80%"; exit 1)
+	@rm -f coverage.out
+
+# Format Go source files
+fmt:
+	gofmt -w cmd internal pkg

pkg/contactform/types.go

@@ -1,3 +1,6 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: MIT
+
 //go:build linux || freebsd
 
 // Package contactform provides reusable types and validation

pkg/contactform/validate.go

@@ -1,3 +1,6 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: MIT
+
 //go:build linux || freebsd
 
 package contactform

pkg/contactform/validate_test.go

@@ -1,3 +1,6 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: MIT
+
 //go:build linux || freebsd
 
 package contactform