doiget-mcp

stdio MCP server for doiget. Exposed by the doiget serve subcommand from doiget-cli so an MCP host (Claude Desktop, Cursor, Codex, Claude Code) can resolve DOIs and arXiv ids, fetch Open Access PDFs through official publisher APIs, and inspect the local store.

Status

Phase 0 skeleton. Server::new(...) constructs a server bound to a resolved doiget_core::CapabilityProfile, but Server::run currently returns an error of the form "doiget-mcp vX.Y.Z (Phase 0): MCP server is not yet implemented". The JSON-RPC loop, tool dispatch, and the 9-tool surface land in Phase 3. See docs/PHASES.md for the implementation plan.

This crate is published to crates.io ahead of Phase 3 so that downstream tooling (packagers, capability profile consumers, and the doiget-cli serve subcommand) can take a stable dependency on the type surface.

Why stdio only

doiget speaks stdio JSON-RPC only. There is no HTTP / SSE / WebSocket transport, and there will not be one. This is a permanent architectural decision recorded in ADR-0001 — MCP transport is stdio only, and it is enforced structurally:

• No Cargo feature exists for an HTTP transport.
• cargo-deny bans HTTP server crates (axum, actix-web, warp, tide, hyper server) workspace-wide.
• clippy::print_stdout is deny in this crate so stdout stays a JSON-RPC frame channel only. Logs go to stderr via tracing-subscriber.

The defense-in-depth payoff: no listening port, no auth surface, no SSRF vector, no multi-tenant accounting. doiget remains a strictly local tool that the user runs on their own machine under their own credentials.

Tool surface (planned, Phase 3)

The 9-tool baseline shipped at Phase 3 (full spec in docs/MCP_TOOLS.md):

Phase 4 adds doiget_expand_citation_graph, doiget_bibtex_export, and doiget_csl_export. Permanent exclusions (no doiget_delete_paper, doiget_set_credentials, doiget_run_shell, doiget_fetch_url) are listed in docs/MCP_TOOLS.md §6.

Embedding in an MCP host

End users do not depend on this crate directly. MCP hosts launch the server by configuring the doiget binary's serve subcommand, e.g. for Claude Desktop:

{
  "mcpServers": {
    "doiget": {
      "command": "doiget",
      "args": ["serve"]
    }
  }
}

stdin EOF triggers a 5-second graceful shutdown. See docs/MCP_TOOLS.md §8 for lifecycle details and docs/INTEGRATION/ for per-host integration notes.

License

MIT. See LICENSE at the workspace root.