#compare.sr.ht

A git compare/diff viewer for a self-hosted SourceHut instance. It compares two refs (branches, tags, or commits) of any git.sr.ht repository — base...head or base..head — and renders the diff with @pierre/diffs (Shiki-based syntax-highlighted diffs) and a @pierre/trees file tree, plus a single-commit view. Runs at https://compare.srht.bigb.es.

#Architecture

The service integrates into SourceHut purely through configuration — no upstream sources are modified (see the sourcehut-custom-service integration model). It is stateless: it owns no database and no object storage. Repository data is read directly from the bare repos on disk ({[git.sr.ht] repos}/~{owner}/{name}) by shelling out to git, exactly as git.sr.ht itself does. Every request is authorized against the git.sr.ht GraphQL API using core-go's internal-auth client, acting as the cookie's logged-in user (or anonymously, which the API scopes to public/unlisted repos). Identity comes from decrypting the shared sr.ht.unified-login.v1 cookie with the instance's network key. Pages are server-rendered Go templates that reproduce the SourceHut chrome; the diff/tree UI is one vendored esbuild bundle driven by a JSON blob embedded in the page.

#Layout

• core/ — pure domain: owner/repo/ref validation, the compare-spec grammar, sentinel errors. No external dependencies.
• gitx/ — git shell-out (refs, diff, log, commit) with output limits. (phase 1)
• authz/ — cookie→identity and the GraphQL authorizer with a short TTL cache. (phase 1)
• web/ — chi router, handlers, chrome, Go templates, embedded static assets. (phase 2)
• frontend/ + scss/ — build-time TypeScript diff bundle and the SCSS entry. (phase 2)
• cmd/comparesrht/ — the daemon entry point and startup validation. (phase 3)
• contrib/ — nginx server block and systemd unit.

The core-go dependency is pinned to a private fork (git.srht.bigb.es/~bigbes/core-go) via a replace directive in go.mod; the fork carries one production S3 patch on top of upstream.

#Build requirements

• Go 1.26+ (module go.bigb.es/sourcehut-compare).
• sassc and minify — CSS pipeline (make css), building against the shared sourcehut scss partials installed at /usr/share/sourcehut/scss.
• Node.js (build time only) — the frontend diff bundle (make bundle, esbuild). The vendored web/static/bundle.js is committed, so Node is not needed at runtime.

make build   # compile the service
make test    # go test ./...
make css     # build the hashed stylesheet
make bundle  # build the vendored frontend bundle

#Configuration

See config.example.ini. On a real instance, append the [compare.sr.ht] section to the shared /etc/sr.ht/config.ini; the service reads the instance's existing shared keys ([sr.ht], [webhooks], [meta.sr.ht], [git.sr.ht]) in place.

#Deployment

Filled in during phase 3. In outline: install the binary and static assets (make install), add the [compare.sr.ht] config section, install contrib/compare.sr.ht.conf (nginx) and contrib/compare-srht.service (systemd), point DNS compare.srht.bigb.es at the instance, and ensure this host is within the git.sr.ht API's internal-ipnet.