mcp/CHANGELOG.md

Changelog — einherjar/mcp

All notable changes to this module are documented here. Format follows Keep a Changelog. This module adheres to Semantic Versioning.

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[0.1.1] — 2026-05-29

Patch release. Two changes to cmd/server make the binary cleaner to run behind a unix socket on a reverse-proxied host, plus two repository-hygiene changes that follow from the same deployment exercise.

Added

• Systemd socket activation in cmd/server. The binary inherits the listener from LISTEN_FDS via github.com/coreos/go-systemd/v22/activation when present, falling back transparently to TCP -addr binding otherwise. Startup log records "mode":"socket-activated" or "mode":"tcp". Same binary, no flag or env var to toggle.

Changed

• Health probe path moved from /healthz to <path>/healthz (default /mcp/healthz). Lets a reverse proxy expose the entire MCP service through one location prefix. v0.1.0 consumers hitting the old /healthz route receive 404; update to /mcp/healthz (or whatever path matches your -path flag).
• README.md deployment section rewritten to be hosting-agnostic. Points at the Dockerfile and systemd socket activation as supported binary modes without prescribing one operator's setup. Adds the SSE-buffering caveat once: any reverse proxy must disable response buffering on the /mcp location, otherwise Server-Sent Events get batched and streamable MCP sessions break.
• /deploy/ is now .gitignored. Local deployment artefacts (systemd units, reverse-proxy templates, per-release scripts) are operator-specific by design and live outside the public repository. The Dockerfile at the module root remains the only portable, public-facing build artefact.

Dependencies

• Added: github.com/coreos/go-systemd/v22 v22.7.0 — used by cmd/server to detect and use a systemd-passed listener.

Upgrade notes

If you…	Action
Consume the MCP service from an MCP client (Claude, Cursor, Zed, etc.)	None — /mcp is unchanged
Monitor the service via the healthz probe	Update the probe URL from /healthz to /mcp/healthz
Run the binary directly (no reverse proxy)	None — -addr TCP binding still works the same way
Run the binary under systemd with a socket unit	The same binary now picks up the inherited listener automatically

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[0.1.0] — 2026-05-29

Initial release. The mcp module hosts the Einherjar Model Context Protocol server — a remote, streamable-HTTP service that teaches AI assistants about every other module of the framework.

Added

Server (cmd/server)

• Streamable-HTTP MCP server built on github.com/modelcontextprotocol/go-sdk v1.0.0
• Listen address and HTTP path configurable via EINHERJAR_MCP_ADDR (default :8080) and EINHERJAR_MCP_PATH (default /mcp)
• /healthz liveness endpoint
• Embedded framework index loaded once at startup; in-memory for the lifetime of the process

Indexer (cmd/indexer)

• Walks an Einherjar repository checkout and produces data/index.json
• For each sibling module captures: import path, Go version, README (full + extracted tagline), CHANGELOG, root doc.go package comment, sub-package doc comments, every exported symbol (type/interface/func/method/const/var) with signature + godoc, ADRs, README code-fence examples, dependency edges from go.mod, and the contents of compliance_test.go (interface assertions + structural test names)
• Appends a synthetic wire module documenting canonical Einherjar application wiring conventions

Tools (10)

• list_modules — enumerate every Einherjar module with purpose and sub-packages
• get_module — package doc, dependencies, sub-packages, key symbols, ADRs, compliance counts; optional embedded README
• search_symbols — full-text search across name, doc, sub-package, module
• get_symbol — full signature, doc, and source location for one symbol
• list_adrs — list architectural decision records, optionally filtered by module
• get_adr — fetch one ADR's markdown body
• get_example — canonical usage snippets extracted from module READMEs and the wire conventions
• get_compliance — interface assertions and structural test names from a module's compliance_test.go
• get_changelog — full CHANGELOG.md markdown for one module
• validate_snippet — pattern-match a Go snippet against framework conventions; returns findings with severity, hint, and line

Validation rules (8)

• launcher.missing-run, launcher.no-components, launcher.run-error-discarded
• logz.direct-env-read
• web.server-not-appended
• wire.hook-bad-signature, wire.hook-outside-beforestart, wire.route-specific-after-param

Synthetic wire module

• Authored in internal/index/builtins/README.md; participates in list_modules, get_module, and get_example exactly like a real module
• Sections: project layout, Run() shape, feature hook shape, route ordering, authorization, middleware helpers, adapters at the wire boundary, migrations and seeds
• All examples use einherjar import paths

Packaging

• Multi-stage Dockerfile that builds from the einherjar repository root (docker build -f mcp/Dockerfile .) so the indexer can walk every sibling module at image-build time
• Distroless runtime image; static binary; non-root user