DAG Studio MCP server

dag-studio-mcp

Model Context Protocol (MCP) server for the DAG Studio causal-inference engine. It lets AI agents construct, analyze, and validate causal directed acyclic graphs (DAGs) using the same engine that powers the DAG Studio canvas.

Built and maintained by Black Swan Causal Labs. Listed in the RWE MCP Registry.

Tools

Every analytical response carries an engine_version stamp, a concordance attestation, a diagnostics block with severity-coded flags, and citations to the underlying methods literature.

Validation

The engine is validated four ways for coherence: against Pearl (2009) theory, against the reference implementation dagitty (Textor et al. 2016), against DAG Studio's own analytical results, and empirically via compute_bias on simulated data.

• 35 canonical cases: T01 to T15 (structural identification) and EM01 to EM20 (effect modification), runnable live via validate_engine.
• A release-gate concordance check runs the engine head-to-head against dagitty (vendored at upstream commit 7a65777) and stamps the attestation surfaced in tool responses.
• 93 unit and integration tests across the engine bindings, the tool layer, and the auth gate.

Hosted endpoint

The server runs as a Cloudflare Worker (Streamable HTTP):

https://dagstudio-mcp.blackswancausallabs.com/mcp

Access is token-gated during the trial period. Request a token at jdiazdecaro@blackswancausallabs.com. Tokens are accepted either as a bearer header or as a ?token= query parameter (the query form exists for clients whose connector UI cannot set custom headers, such as the Claude.ai web connector).

Claude Code:

claude mcp add --transport http dag-studio \
  https://dagstudio-mcp.blackswancausallabs.com/mcp \
  --header "Authorization: Bearer <your token>"

Claude.ai web: add a custom connector pointed at https://dagstudio-mcp.blackswancausallabs.com/mcp?token=.

Repository layout

• dag-engine.js / dag-engine.d.ts: the analytical engine, a pure ESM module with no runtime dependencies
• src/tools/: one file per tool, each exporting { InputSchema, OutputSchema, descriptor, handler }
• src/worker/: Cloudflare Worker transport and the token gate (auth.ts)
• src/index.ts: stdio entry point for local use
• ci/: release-gate concordance harness against vendored dagitty
• tests/: unit and integration tests (npm test)
• MCP_REQUIREMENTS.md: the v1 specification
• FDAGUIDANCEALIGNMENT.md: mapping of DAG Studio capabilities onto FDA draft RWE guidance protocol elements

Shortened. The full README is on GitHub.