A side-by-side look at the Chembl MCP Server and Clinicaltrialsgov MCP Server MCP servers: transport, auth, tools, quality signals, and the config to install either one in Claude, Cursor, Windsurf or VS Code.
Verdict: choose Chembl MCP Server for biology & bioinformatics work as a local process; choose Clinicaltrialsgov MCP Server for biology & bioinformatics as a local process. You can also run both side by side in one mcpServers block.
CANVAS_PROVIDER_TYPE, CHEMBL_MAX_SPILL_ROWS, CHEMBL_DATAFRAME_DROP_ENABLED.chembl_search_molecules, chembl_get_bioactivities, chembl_search_targets.clinicaltrials_search_studies, clinicaltrials_get_study_record, clinicaltrials_get_study_count.Rows where the two servers differ are marked.
| Spec | ||
|---|---|---|
| Category | Biology & Bioinformatics | Biology & Bioinformatics |
| Quality signal | 56/100 · Good | 63/100 · Good |
| Install command | Confirmed | Confirmed |
| Transport | Local subprocess (stdio) | Local subprocess (stdio) |
| Auth | Not declared | No auth required |
| Pricing | Not declared | Free |
| Required env vars | CANVAS_PROVIDER_TYPECHEMBL_MAX_SPILL_ROWSCHEMBL_DATAFRAME_DROP_ENABLED | None listed |
| Verified owner | Community listing | Community listing |
| GitHub stars | 1 | 99 |
| Directory activity | 1 views 0 installs 0 upvotes | 3 views 0 installs 0 upvotes |
| Tools | 8 | 7 |
| Full listing | View Chembl MCP Server | View Clinicaltrialsgov MCP Server |
chembl_search_moleculesFind compounds by name / ChEMBL ID / InChIKey, or run a structure search (exact \chembl_get_bioactivitiesThe flagship compound↔target bridge: bioactivity measurements for a molecule, a target, or **both** (the compound×target pair), ranked on `pchembl_value`, or the measurements without one via `potency_view`. Large sets spill to a canvas.chembl_search_targetsResolve a protein / gene symbol / UniProt accession to the ChEMBL target ID `chembl_get_bioactivities` needs.chembl_get_drug_infoDrug pharmacology — mechanism(s) of action, molecular target(s), action type, first-approval year, and clinical indications.chembl_get_assayAssay provenance behind a bioactivity row — type, target, organism, and ChEMBL's 1–9 confidence score.chembl_dataframe_queryRun a read-only SQL `SELECT` over the bioactivity rows spilled to a canvas — rank, group, dedupe, aggregate across the full set.chembl_dataframe_describeList the tables and columns staged on a canvas, so you can write correct SQL before querying.chembl_dataframe_dropDrop a named staged table from a canvas. Opt-in via `CHEMBL_DATAFRAME_DROP_ENABLED=true` — absent from `tools/list` when off, since TTL already reclaims staged tables.clinicaltrials_search_studiesSearch studies with full-text and field-specific queries, status/phase/geographic filters, pagination, sorting, and field selectionclinicaltrials_get_study_recordFetch a single study by NCT ID — full protocol record with optional location/outcome/reference capsclinicaltrials_get_study_countFast total study count for a query, without fetching dataclinicaltrials_get_field_valuesDiscover valid values for API fields, with per-value study countsclinicaltrials_get_field_definitionsResolve valid field names — keyword search, path drill-down, or top-level overviewclinicaltrials_get_study_resultsFetch posted results — outcomes, adverse events, participant flow, baseline — for completed studiesclinicaltrials_find_eligibleMatch patient demographics and conditions to candidate recruiting trials, without checking inclusion/exclusion criteriaPaste either block (or both) into your client config, e.g. claude_desktop_config.json or ~/.cursor/mcp.json. We only show a config when the install command is confirmed.
{
"mcpServers": {
"chembl-mcp-server": {
"command": "bunx",
"args": [
"@cyanheads/chembl-mcp-server@latest"
],
"env": {
"CANVAS_PROVIDER_TYPE": "YOUR_CANVAS_PROVIDER_TYPE_HERE",
"CHEMBL_MAX_SPILL_ROWS": "YOUR_CHEMBL_MAX_SPILL_ROWS_HERE",
"CHEMBL_DATAFRAME_DROP_ENABLED": "YOUR_CHEMBL_DATAFRAME_DROP_ENABLED_HERE"
}
}
}
}
{
"mcpServers": {
"clinicaltrialsgov-mcp-server": {
"command": "npx",
"args": [
"-y",
"clinicaltrialsgov-mcp-server"
]
}
}
}