Context Keeper Remote MCP Server

context-keeper-remote

Part of the xylem stack.

A remote MCP server on Cloudflare Workers that exposes context-keeper's rationale store (decisions, pipelines, constraints) over Streamable HTTP. It works as a claude.ai custom connector, including on mobile, so your project's decisions and constraints are available from any Claude session — no PC left running, no tunnel.

Self-host your own copy in a few clicks with the button above — Cloudflare copies this repo into your GitHub account, creates a fresh D1 database for you, and deploys the Worker. Then you add one secret and paste a URL into Claude. Full walkthrough below; every step is a click, no command line anywhere.

The maintainer's own instance runs at https://context-keeper-remote.jarmstrong158.workers.dev. Yours will be at your own subdomain after you deploy.

Why it's built this way

• Worker, not tunnel — no "PC must be on" dependency.
• D1, not KV — row-level writes and WHERE queries; two writers (desktop + mobile) don't clobber each other the way whole-file JSON read-modify-write does.
• Stateless handler, no Durable Objects — the tools are stateless RPCs against D1, so the Worker runs on the Cloudflare free plan.
• Secret-path auth — claude.ai custom connectors don't reliably send custom bearer headers, so the token is the last path segment of the URL. The URL is the credential.
• Self-migrating — the Worker creates its own D1 schema at runtime, so a brand-new empty database needs no manual SQL (verified by a cold-start test).

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Self-host it (one-click, no command line)

Step 1 — Click "Deploy to Cloudflare"

Click the Deploy to Cloudflare button at the top of this page. Cloudflare will:

1. Ask you to authorize GitHub and pick an account — it copies this repo into your GitHub account (you get your own repo).
2. Automatically create a new D1 database in your Cloudflare account and bind it to the Worker. (This works because the Worker's config declares the database binding without a hard-coded id, so Cloudflare provisions a fresh one for you.)
3. Set up Workers Builds so every push to your new repo redeploys automatically.
4. Build and deploy the Worker.

When it finishes, your Worker is live at https://context-keeper-remote.<your-subdomain>.workers.dev. Note that URL — you'll need it in Step 3. (You can always find it under Workers & Pages in the dashboard.)

Nothing to configure in the repo, and no SQL to run — the database starts empty and the Worker creates its tables on the first request.

Step 2 — Add the AUTH_TOKEN secret (Cloudflare dashboard)

The Worker refuses every request until it has an auth token, so set one:

1. Cloudflare dashboard → Workers & Pages → your context-keeper-remote Worker.
2. Settings → Variables and Secrets → Add.
3. Type: Secret. Name: AUTH_TOKEN. Value: a long random string (32+ characters — treat it like a password). Save/Deploy.

That value is your connector's password. Keep it somewhere safe; you'll paste it in the next step.

agentsync-remote uses the same AUTH_TOKEN scheme, and additionally needs, in its Worker's Variables and Secrets:

• a Secret named GH_PAT — a GitHub personal access token, and
• a Variable named REPO — set to the owner/repo it should sync.

Those two do not apply to context-keeper-remote (this repo) — it only needs AUTH_TOKEN. See the agentsync-remote README for its specifics.

Step 3 — Add the custom connector in claude.ai

1. claude.ai → Settings → Connectors → Add custom connector.

2. Paste your Worker URL with the token as the final path segment:

   https://context-keeper-remote.<your-subdomain>.workers.dev/mcp/<AUTH_TOKEN>
   

   Replace <your-subdomain> with your Worker's subdomain (Step 1) and <AUTH_TOKEN> with the exact value you set (Step 2).

3. Save. The tools (record_entry, get_context, query_entries, …) are now available in your Claude sessions.

Check it works: ask Claude to call get_project_summary. If it answers, the whole chain (deploy → auto-provisioned D1 → auto-migration → auth) is working.

Step 4 — Migrate existing local data (optional)

If you already run local context-keeper, ask Claude (with the connector enabled) to call import_entries, pasting each file's contents:

• decisions.json → import_entries(project, kind="decision", entries=[...])
• pipelines.json → import_entries(project, kind="pipeline", entries=[...])
• constraints.json → import_entries(project, kind="constraint", entries=[...])

Incoming ids are preserved; existing ids are reported, never overwritten.

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⚠️ Security: the connector URL is a credential

The URL you paste into Claude embeds AUTH_TOKEN as its last path segment. Anyone who has the full …/mcp/<AUTH_TOKEN> URL can read and write your entire store. Treat it exactly like a password:

• Don't share it, screenshot it, or paste it anywhere it could be logged.
• Requests to any other path, or with the wrong token, get a bare 404 with no detail (a valid token used with a non-POST method gets 405).
• To rotate: change AUTH_TOKEN in the Cloudflare dashboard (Step 2). This immediately invalidates every old URL — any connector using the previous token starts getting 404s until you update it in claude.ai (Step 3) with the new value.

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Tools

Every tool takes an optional project; if omitted it falls back to the configured default_project (set it once with config — op='set', key default_project).

The unified tools (config, record_entry) are the current surface; the older per-operation tools remain as deprecated aliases so existing callers keep working. New work should prefer the unified tools.

Entry conventions

• Decisions use summary, problem, why_chosen, what_we_tried, tradeoffs, tags. The deprecated rationale field is accepted on input and mapped to why_chosen when why_chosen is absent.
• Constraints use rule, reason, tags.
• Pipelines use name, purpose, steps, plus any extra fields you pass.
• ids are per project+kind: dec-001, pipe-003, con-012. Because the same id recurs across projects, the D1 primary key is composite (project, id).

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For maintainers / contributors

Everything above is for self-hosters. This section is for working on the code itself.

Config layout: how one repo serves both the button and CI

wrangler.toml has two profiles:

• Default (top level) — the D1 binding is declared without a database_id. This is what the Deploy button, wrangler dev, and the local test suite use. With no id, Cloudflare auto-provisions a fresh database for each self-hoster.
• [env.production] — pins the maintainer's real database_id and the Worker name. The maintainer's CI deploys with wrangler deploy --env production so it keeps hitting the same database and the same URL. Self-hosters never touch this env.

Deploy pipeline (maintainer only)

.github/workflows/deploy.yml runs on push to main, and is gated with if: github.repository == 'jarmstrong158/context-keeper-remote' so forks (which deploy via Workers Builds instead) don't run failing Actions. Steps: checkout → Node 22 (Wrangler needs ≥ 22) → npm ci → npm test → wrangler deploy --env production. Tests gate the deploy. It reads two GitHub repo secrets, CLOUDFLARE_API_TOKEN (needs Workers Scripts: Edit) and CLOUDFLARE_ACCOUNT_ID — distinct from the Worker's own AUTH_TOKEN.

Local development

No network and no Cloudflare credentials required — tests run against a local workerd D1 via @cloudflare/vitest-pool-workers. Requires Node ≥ 22.

npm install
npm test          # vitest: migrations, cold-start, CRUD, id sequencing, auth, import, ...
npm run typecheck # tsc --noEmit

Live smoke test

After a deploy, from any machine with network access:

WORKER_URL="https://context-keeper-remote.<subdomain>.workers.dev/mcp/<AUTH_TOKEN>" \
  node scripts/smoke-test.mjs

Runs initialize → tools/list → record_decision → query_entries against the live worker.

Layout

src/index.ts             fetch handler: token check -> MCP dispatch (schema ensured lazily on first tools/call, not on the handshake)
src/mcp.ts               stateless Streamable HTTP MCP server (createMcpHandler)
src/db.ts                D1 access + runtime migration runner + id generation
src/entries.ts           payload normalization, insert-with-retry, keyword scoring
src/tools/*.ts           one module per tool group
schema.sql               reference copy of the DDL the migration runner embeds
wrangler.toml            default (auto-provision) + [env.production] (pinned) config
.github/workflows/deploy.yml   test-then-deploy on push to main (maintainer repo)
scripts/smoke-test.mjs   live JSON-RPC round-trip check
test/                    vitest suite (local workerd D1, no network)

Troubleshooting the maintainer deploy

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Related

• context-keeper — the local stdio original this Worker hosts as a remote transport.
• xylem — the stack this is part of.