Bun bridge on :3900 that wraps context7's public API and exposes the
surface gateway consumes for Phase 45 drift checks. Own port so a
failure here never tips over mcp-server on :3700.
Endpoints:
GET /health status + cache stats
GET /docs/:tool resolve tool → library_id → fetch
docs → return descriptor
{snippet_hash, last_updated,
source_url, docs_preview, ...}
GET /docs/:tool/diff?since=X compare current snippet_hash to X;
returns {drifted: bool, current,
previous, preview if drifted}
GET /cache debug dump of cached entries
Implementation notes:
- 5 minute in-memory cache (context7 rate-limits by IP; gateway
drift-checks are the hot caller)
- 1500-token slices from context7 (enough for drift-meaningful
hash, not so much we hammer their API)
- snippet_hash = SHA-256 prefix (16 hex chars) of fetched content
- Library resolution prefers "finalized" state; falls back to top
result if none finalized
Verified live against context7.com:
- /health → ok, 0 cache, 300s TTL
- /docs/docker → library_id /docker/docs,
title "Docker", hash
475a0396ca436bba, last
updated 2026-04-20
- /docs/docker (again) → cache hit, 0.37ms
(5400× speedup)
- /docs/docker/diff?since=stale-hash-0000 → drifted=true, preview
included
- /docs/docker/diff?since=<current hash> → drifted=false, preview
omitted (honest: no
drift to show)
Not yet wired:
- Gateway consumer (Phase 45 slice 3):
/vectors/playbook_memory/doc_drift/check/{id} calls this bridge
and updates DocRef.snippet_hash + doc_drift_flagged_at
- Systemd unit (bridge is manual-start for now, same as bot/)
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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