# io.github.cyanheads/clinicaltrialsgov-mcp-server (io.github.cyanheads/clinicaltrialsgov-mcp-server@2.9.2) > Source: > Published: 2026-08-21 22:39:28+00:00 [← Index](/leaderboard) # io.github.cyanheads/clinicaltrialsgov-mcp-server Search ClinicalTrials.gov — find studies, retrieve results, match patients to eligible trials. The current version, v2.9.2, was published to the official MCP registry on 2026-08-21. It is distributed as clinicaltrialsgov-mcp-server on npm and as a hosted remote over streamable-http, filed under Search by this index, and declares 8 environment variables. Removals and unreachable sources are measured across every server this index tracks, contract drift across the servers that answer in consecutive snapshots; [the index's current counts](/stats) put this record in context. ## Using io.github.cyanheads/clinicaltrialsgov-mcp-server in Claude, Cursor, Gemini CLI, Cline, or Zed? MCP tool contracts can change remotely with no version bump. The mcpindex gate pins each contract and **HOLDs the call** when it drifts-before your agent acts. Zero credentials. This is not the package install for this server itself (use **Install this server** for that). Rewrites your MCP host config so each server launches behind the gate. Inspect first: curl -fsSL https://mcpindex.ai/install.sh | less ``` uv tool install mcpindex-gate && mcpindex-config-wire ``` [method](/methodology) Semantic screen found no manipulation pattern in the description. Conformance probe not yet run. `mcpindex.integrity.description` passINFOevidence“Declared capability, no hidden instructions”via static_description - - Semantic screen only - the deterministic conformance probe has not run on this server - - Confidence is reported but not yet calibrated (v1) - - Screen reads the tool description, not the live behavior - - advisory - - registry description only no input schema - - screen model 8b - - Still current: the description we screened is unchanged, re-checked against the registry - - The registry listing (version, packages, links) changed after this screen ran - the description we assessed did not Semantic screen: an LLM judge reads the tool description for hidden instructions (status PARTIAL). A pass means the description is not lying, not that the tool is safe: a high-capability tool with an honest description still warrants caution. The deterministic conformance probe has not been run on this server yet, so the screen here is semantic-only. Posture: advisory. Confidences are reported but not yet calibrated (calibrated=false at v1). Full verdict history is not shown on this page. Own this server? [Screen its description →](/screen) ## That verdict was true at screening time (snapshot 2026-08-21). Contracts can change after screening, with no version bump. The gate pins io.github.cyanheads/clinicaltrialsgov-mcp-server’s tool contracts on first sight and holds any silent change before your agent acts - the check that keeps being true on Tuesday. [See your first HOLD in 2 minutes →](/guides/install-the-gate-first-hold) Related: [how to trust an MCP server](/guides/how-to-trust-an-mcp-server) · [screen before install](/guides/screen-mcp-server-before-install) · [silent contract drift](/guides/mcp-silent-contract-drift) People vet a server before wiring it in. One line on your project site or docs answers that with an independent record: screening verdict, registry provenance, contract drift history. It stays current as new screens and drift events land. ``` [Independent trust record for io.github.cyanheads/clinicaltrialsgov-mcp-server](https://mcpindex.ai/server/io-github-cyanheads-clinicaltrialsgov-mcp-server) - screening verdict, registry provenance, and contract drift monitoring. Independent trust record for io.github.cyanheads/clinicaltrialsgov-mcp-server - screening verdict, registry provenance, and contract drift monitoring. ``` A live verdict badge for your README or listing. It reflects the current screen, links back here, and updates when the verdict does. ``` [![mcpindex](https://mcpindex.ai/api/v1/badge/io-github-cyanheads-clinicaltrialsgov-mcp-server)](https://mcpindex.ai/server/io-github-cyanheads-clinicaltrialsgov-mcp-server) mcpindex verdict ``` `CT_API_BASE_URL` ClinicalTrials.gov API base URL. `CT_REQUEST_TIMEOUT_MS` Per-request timeout in milliseconds. `CT_MAX_PAGE_SIZE` Maximum page size cap. `MCP_LOG_LEVEL` Sets the minimum log level for output (e.g., 'debug', 'info', 'warn'). `CT_API_BASE_URL` ClinicalTrials.gov API base URL. `CT_REQUEST_TIMEOUT_MS` Per-request timeout in milliseconds. `CT_MAX_PAGE_SIZE` Maximum page size cap. `MCP_HTTP_HOST` The hostname for the HTTP server. `MCP_HTTP_PORT` The port to run the HTTP server on. `MCP_HTTP_ENDPOINT_PATH` The endpoint path for the MCP server. `MCP_AUTH_MODE` Authentication mode to use: 'none', 'jwt', or 'oauth'. `MCP_LOG_LEVEL` Sets the minimum log level for output (e.g., 'debug', 'info', 'warn'). [methodology](/methodology) [YTDL RMCPai.dinglebear/rytdl](/server/ai-dinglebear-rytdl) yt-dlp search, download, metadata, delivery, and Plex workflows over MCP and CLI. [Fodda Topic & Trend Researchai.fodda/topic-research](/server/ai-fodda-topic-research) Trend, stats & insight search across PSFK expert graphs with citable sources. [io.github.cyanheads/college-scorecard-mcp-serverio.github.cyanheads/college-scorecard-mcp-server](/server/io-github-cyanheads-college-scorecard-mcp-server) Search, compare, and analyze U.S. college data — costs, earnings, programs, and outcomes.