cyanheads-mcp-server

Public Hosted Server: https://cyanheads.caseyjhand.com/mcp

Overview

Fleet discovery for the cyanheads MCP ecosystem, built on a hosted fleet.json catalog of pre-computed tool and server embeddings. Search the catalog by natural-language query, or resolve a known tool or server name to its description, connection URL, and per-client install snippet. Runs as a stdio process, a local Streamable HTTP server, or the public hosted endpoint above.

Tools

Related MCP server: embecode

Capability reference

cyanheads_search_catalog tool

• query 1–500 raw characters, with non-whitespace text required; surrounding whitespace is trimmed before embedding and echo. scope selects tools (default) or servers; optional category: research, government, public-data, utility; limit 1–20 (default 5).

• Results carry cosine-similarity score ([0, 1], comparable within one response). Tool searches include a servers roll-up with ten entries per page and serversTotal; an unloaded catalog returns retryable catalog_empty.

• Page results with offset and the tools-scope roll-up independently with serversOffset (both default to 0). Reuse the same query, scope, category, and limit with nextOffset / nextServersOffset; null means exhausted. Each call uses the current catalog, so a refresh between pages can change ordering. Servers scope requires serversOffset: 0 and omits roll-up fields.

• SIMILARITY_FLOOR (default 0.3) filters matches before the limit applies.

cyanheads_describe_entry tool

• name 1–64 characters accepts a tool or server name, auto-detected or pinned via kind. Exact names win, then unique case-insensitive names; output uses canonical names. client optionally selects claude-code, codex, cursor, gemini, streamable-http, or curl.

• Both kinds return connection metadata and install snippets; server results also include the full tool inventory. Published servers get local snippets; hosted servers also get HTTP snippets. For local-only entries, client: "curl" returns successful metadata with an installNotice naming a stdio client to try. Required environment variables remain visible even without snippets.

• Descriptions are catalog text; obtain tool schemas from the connected server's tools/list.

• Failures return not_found, ambiguous_kind (set kind), or retryable catalog_empty.

Features

Built on @cyanheads/mcp-ts-core: stdio and Streamable HTTP transports, pluggable auth (none / jwt / oauth), swappable storage (in-memory, filesystem, Supabase, Cloudflare KV/R2/D1), structured logging with optional OpenTelemetry tracing.

Catalog-specific:

• Hourly background catalog refresh (CATALOG_REFRESH_SECONDS, default 3600) with an atomic index swap when generatedAt changes — no restart needed

• Empty catalogs and conflicting duplicate identities fail before index replacement; refresh retains the last valid catalog. Identical duplicates collapse before indexing, with a bounded load-time warning; servers with no tools remain valid.

• Query embeddings are computed at request time via @huggingface/transformers; document embeddings are pre-computed, L2-normalized, and Matryoshka-truncated, shipped inside fleet.json

• The embedding model is warmed up during startup, before OpenTelemetry's HTTP instrumentation patches fetch — avoids a cold-cache model-load failure under OTEL

• Self-describing: cyanheads_describe_entry resolves this server's own name and tools from a static fallback record, consulted only when the remote catalog doesn't carry an entry for it

• CATALOG_URL can point at any endpoint serving the same schema, to front a custom fleet

Agent-friendly output:

• Search responses echo the effective query, report the total match count before the limit, and include broadening guidance when nothing matches

• Discriminated result.kind (tool | server) on cyanheads_describe_entry lets callers branch on data, not string parsing

• Every search result carries a score field for trust calibration, plus a servers roll-up so agents can see which servers matched without a second call

Getting started

Public Hosted Instance

A public instance is available at https://cyanheads.caseyjhand.com/mcp — no installation required. Point any MCP client at it via Streamable HTTP:

{
  "mcpServers": {
    "cyanheads-mcp-server": {
      "type": "streamable-http",
      "url": "https://cyanheads.caseyjhand.com/mcp"
    }
  }
}

For Claude Code:

claude mcp add --transport http cyanheads https://cyanheads.caseyjhand.com/mcp

Self-Hosted / Local

Add the following to your MCP client configuration file.

{
  "mcpServers": {
    "cyanheads-mcp-server": {
      "type": "stdio",
      "command": "bunx",
      "args": ["@cyanheads/cyanheads-mcp-server@latest"],
      "env": {
        "MCP_TRANSPORT_TYPE": "stdio",
        "MCP_LOG_LEVEL": "info"
      }
    }
  }
}

Or with npx (no Bun required):

{
  "mcpServers": {
    "cyanheads-mcp-server": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@cyanheads/cyanheads-mcp-server@latest"],
      "env": {
        "MCP_TRANSPORT_TYPE": "stdio",
        "MCP_LOG_LEVEL": "info"
      }
    }
  }
}

Or with Docker:

{
  "mcpServers": {
    "cyanheads-mcp-server": {
      "type": "stdio",
      "command": "docker",
      "args": ["run", "-i", "--rm", "-e", "MCP_TRANSPORT_TYPE=stdio", "ghcr.io/cyanheads/cyanheads-mcp-server:latest"]
    }
  }
}

For Streamable HTTP, set the transport and start the server:

MCP_TRANSPORT_TYPE=http MCP_HTTP_PORT=3010 bun run start:http
# Server listens at http://localhost:3010/mcp

Prerequisites

• Bun v1.4.0 or higher (or Node.js v24+).

Installation

1. Clone the repository:

git clone https://github.com/cyanheads/cyanheads-mcp-server.git

2. Navigate into the directory:

cd cyanheads-mcp-server

3. Install dependencies:

bun install

4. Configure environment:

cp .env.example .env
# edit .env to override any defaults

Configuration

All configuration is validated at startup via Zod schemas in src/config/server-config.ts. Every variable has a sensible default — out of the box, the server points at the canonical cyanheads fleet.

See .env.example for the full list of optional overrides.

Running the server

Local development

• Build and run the production version:

  # One-time build
  bun run rebuild
  
  # Run the built server
  bun run start:http
  # or
  bun run start:stdio

• Run checks and tests:

  bun run devcheck  # Lints, formats, type-checks, runs MCP and packaging linters
  bun run test      # Runs the test suite

Docker

docker build -t cyanheads-mcp-server .
docker run --rm -p 3010:3010 cyanheads-mcp-server

The Dockerfile defaults to HTTP transport, stateless session mode, and logs to /var/log/cyanheads-mcp-server. OpenTelemetry peer dependencies are installed by default — build with --build-arg OTEL_ENABLED=false to omit them.

Project structure

Development guide

See CLAUDE.md for development guidelines and architectural rules. The short version:

• Handlers throw, framework catches — no try/catch in tool logic

• Use ctx.log for logging, ctx.state for storage

• Register new tools in the tools array passed to createApp() in src/index.ts

• Wrap external data: validate raw → normalize to domain type → return output schema; never fabricate missing fields

Contributing

Issues are welcome. Run checks and tests before submitting:

bun run devcheck
bun run test

License

Apache-2.0 — see LICENSE for details.