Chembl MCP server

online · 100% uptime

by cyanheads·io.github.cyanheads/chembl-mcp-server·v0.5.0·1 stars

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Link compounds to protein targets, rank bioactivity, and look up drug mechanisms and indications.

A86/100grade A

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Safety scan

A86/100

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Adoption

Growing

1 stars688 downloads/wk

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How Chembl compares

Against every graded SEO MCP server, from our own scans and uptime checks. Updated after each scan run.

Safety score: 86/100; higher than 74% of 769 SEO servers
Uptime: 100%; of our recent checks; the typical remote SEO server answers 100%
Response time: 221 ms; faster than 61% of 536 SEO servers
GitHub stars: 1; more than 65% of 405 SEO servers
Downloads a week: 688; more than 95% of 170 SEO servers with a package

Release history: 7 versions in the registry since 2026-08-25, latest 2026-10-29, typically one every 7 days.

Install Chembl in Claude Code, Cursor or VS Code

claude mcp add --transport http chembl-mcp-server https://chembl.caseyjhand.com/mcp

Add to Cursor

What the publisher says

From the Chembl repository's README, as published. We do not edit it. Read it on GitHub

@cyanheads/chembl-mcp-server Link compounds to protein targets, rank bioactivity (IC50/Ki/EC50), and look up drug mechanisms and indications over ChEMBL via MCP. STDIO or Streamable HTTP. 7 Tools (+1 opt-in) • 2 Resources

Public Hosted Server: https://chembl.caseyjhand.com/mcp

Overview

Drug-discovery data over ChEMBL (EBI) — the curated link between compounds, protein targets, and measured bioactivity (IC50/Ki/EC50), plus drug mechanisms and indications. Search compounds by name, ID, or structure, resolve protein targets, rank bioactivity measurements, and look up drug mechanisms and indications from any MCP client. Runs as a stdio process, a local Streamable HTTP server, or the public hosted endpoint above.

Tools

Shortened. The full README is on GitHub.

Nothing above is checked by us. What we check is on the safety report.

Chembl: common questions

Is Chembl MCP server safe?: Yes, by our scan: it is graded A (86/100). Read the Chembl safety report
How do I install Chembl?: It runs remotely at chembl.caseyjhand.com. Add it to Claude Code, Cursor, VS Code or Claude Desktop with the snippets above, or call it through the mcp.market gateway without installing anything.
Does Chembl need an API key?: No secret keys are declared. It reads 25 settings from the environment.
Is Chembl maintained?: The last commit was 24 days ago (2026-10-10). The latest release is v0.5.0.
Is Chembl up?: 100% of our last 28 checks got an answer. We check remote servers about four times a day.
What can I use instead of Chembl?: Servers from other publishers that do the same job: three.ws Signals MCP server, Web Validator by DigestSEO MCP server and TypeSafe Jev MCP server.
How does Chembl compare with other SEO MCP servers?: safety score 86/100 (higher than 74% of 769 SEO servers); uptime 100% (of our recent checks; the typical remote SEO server answers 100%); response time 221 ms (faster than 61% of 536 SEO servers). Full comparison.

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Run it through the gateway

With the gateway added, ask your agent for it by name:

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call io.github.cyanheads/chembl-mcp-server → <tool>

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Rating: —
Safety grade: A · 86/100
Stars: 1
Downloads/wk: 688
Price: Free
Licence: Apache-2.0
Transport: Remote · mixed
Uptime: 100% · 28/28 checks
Version: 0.5.0
Category: SEO
Last release: 2026-10-10

Credentials it needs

CANVAS_PROVIDER_TYPEDataCanvas provider for the bioactivity spill and the chembl_dataframe_* SQL tools; DuckDB is the default. Set to 'none' to disable it: large bioactivity sets then inline a preview but never spill.
CHEMBL_API_BASE_URLBase URL for the ChEMBL REST data API. Override for a private mirror or pinned host.
CHEMBL_REQUEST_TIMEOUT_MSPer-attempt timeout in milliseconds for an upstream ChEMBL request, capped by what is left of the call's time budget (45 s for most calls, CHEMBL_SPILL_DEADLINE_MS for a bioactivity spill).
CHEMBL_MAX_PAGE_SIZERows per upstream ChEMBL page (max 1000). The bioactivity spill walks pages of this size; an inline bioactivity page requests its limit, capped at this size.
CHEMBL_DEFAULT_LIMITDefault result limit applied when callers omit it.
CHEMBL_MAX_SPILL_ROWSCeiling on rows chembl_get_bioactivities stages to a DataCanvas table, and so on the upstream page walk behind it. Over the cap the response reports truncated: true and truncated_by: "row_cap".
CHEMBL_MAX_CONCURRENT_PAGESMost chembl_get_bioactivities spill-page requests in flight at once (1–6), shared by every call on the server.
CHEMBL_SPILL_DEADLINE_MSTime budget in milliseconds for one chembl_get_bioactivities spill, its count and page walk (10000–600000). At expiry the rows fetched so far stage with truncated: true and truncated_by: "time_budget".
CHEMBL_DATAFRAME_DROP_ENABLEDSet to 'true' to register the opt-in chembl_dataframe_drop tool (absent from tools/list when off).
MCP_LOG_LEVELSets the minimum log level for output (e.g., 'debug', 'info', 'warn').
MCP_TRANSPORT_TYPESelects the HTTP transport.
MCP_HTTP_HOSTThe hostname for the HTTP server.
MCP_HTTP_PORTThe port to run the HTTP server on.
MCP_HTTP_ENDPOINT_PATHThe endpoint path for the MCP server.
MCP_AUTH_MODEAuthentication mode to use: 'none', 'jwt', or 'oauth'.
MCP_LOG_LEVELSets the minimum log level for output (e.g., 'debug', 'info', 'warn').
CANVAS_PROVIDER_TYPEDataCanvas provider for the bioactivity spill and the chembl_dataframe_* SQL tools; DuckDB is the default. Set to 'none' to disable it: large bioactivity sets then inline a preview but never spill.
CHEMBL_API_BASE_URLBase URL for the ChEMBL REST data API. Override for a private mirror or pinned host.
CHEMBL_REQUEST_TIMEOUT_MSPer-attempt timeout in milliseconds for an upstream ChEMBL request, capped by what is left of the call's time budget (45 s for most calls, CHEMBL_SPILL_DEADLINE_MS for a bioactivity spill).
CHEMBL_MAX_PAGE_SIZERows per upstream ChEMBL page (max 1000). The bioactivity spill walks pages of this size; an inline bioactivity page requests its limit, capped at this size.
CHEMBL_DEFAULT_LIMITDefault result limit applied when callers omit it.
CHEMBL_MAX_SPILL_ROWSCeiling on rows chembl_get_bioactivities stages to a DataCanvas table, and so on the upstream page walk behind it. Over the cap the response reports truncated: true and truncated_by: "row_cap".
CHEMBL_MAX_CONCURRENT_PAGESMost chembl_get_bioactivities spill-page requests in flight at once (1–6), shared by every call on the server.
CHEMBL_SPILL_DEADLINE_MSTime budget in milliseconds for one chembl_get_bioactivities spill, its count and page walk (10000–600000). At expiry the rows fetched so far stage with truncated: true and truncated_by: "time_budget".
CHEMBL_DATAFRAME_DROP_ENABLEDSet to 'true' to register the opt-in chembl_dataframe_drop tool (absent from tools/list when off).

Endpoint

https://chembl.caseyjhand.com/mcp

streamable-http

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