io.github.cyanheads/clinicaltrialsgov-mcp-server
clinicaltrialsgov-mcp-server
Search ClinicalTrials.gov: find studies, retrieve results, match patients to candidate trials.
alive probed 2026-10-15 · HTTP 200
7tools
13ktokens in Claude Opus 5.5
13ktokens in Claude Code
6.3 %of a 200k context window
7.1ko200k_base estimate
296 msto initialize
79 msto list tools
- Endpoint
- https://clinicaltrials.caseyjhand.com/mcp (streamable-http)
- Host
- clinicaltrials.caseyjhand.com
- Protocol
- 2025-11-25
- Reports itself as
- clinicaltrialsgov-mcp-server 2.10.0
- Capabilities
- logging, prompts, resources, tools
- Instructions
- 763 characters
- Claude count
- Claude Opus 5.5, measured 2026-10-14. Counted again when the tool definitions change. Method.
- Repository
- https://github.com/cyanheads/clinicaltrialsgov-mcp-server
- Registry
- active, updated 2026-10-14 · registry entry
- Reachable
- 8 of the last 8 probes
Most expensive tools
| Tool | Tokens (o200k) | Share of this server |
|---|---|---|
| clinicaltrials_search_studies | 2 196 | 31 % |
| clinicaltrials_get_study_count | 1 544 | 22 % |
| clinicaltrials_get_study_results | 1 285 | 18 % |
| clinicaltrials_find_eligible | 823 | 12 % |
| clinicaltrials_get_study_record | 566 | 8 % |
History
We add a row when the result changes. A server with no change keeps its last row.
| Probed | Result | Init | Tools | Claude | o200k |
|---|---|---|---|---|---|
| 2026-10-15 10:33 | alive | 161 ms | 7 | 13k | 7.1k |
| 2026-10-14 18:55 | alive | 4.8 s | 7 | 13k | 7.1k |
| 2026-10-05 14:38 | alive | 296 ms | 7 | 12k | 6.7k |
| 2026-10-05 00:33 | alive | 224 ms | 7 | 6.7k | |
| 2026-10-04 10:04 | alive | 506 ms | 7 | 6.7k | |
| 2026-10-04 07:57 | alive | 466 ms | 7 | 6.7k | |
| 2026-10-03 20:37 | alive | 864 ms | 7 | 6.7k | |
| 2026-10-03 17:53 | alive | 669 ms | 7 | 6.7k |
Badge and feed
[](https://mcpcost.ulehla.dev/s/io.github.cyanheads/clinicaltrialsgov-mcp-server)
An entry for every probe that changed the result, the tool count or the token cost: Atom feed. Add it to a feed reader or a Slack RSS app to hear when the server stops answering or its tool set grows.