ChEMBL
ChEMBL is a manually curated database of bioactive molecules with drug-like properties, maintained by the EMBL-EBI. It provides a REST API for accessing bioactive molecules, drug targets, bioactivity data, approved drugs, clinical trial compounds, and cheminformatics utilities to support drug discovery research.
Limited machine-readable signal and partial portal coverage — documentation a human can read, but little a machine or agent can consume without scraping.
API Evangelist profiles ChEMBL the way a machine reads it — 28 machine-readable artifacts across 16 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — ChEMBL scores 40.7/100 (thin), with a separate agent-readiness read of 48/100 (agent ready). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.
Kin Score
How this is scored →scored 2026-07-27 · rubric v0.5
How we profile ChEMBL
Each block below is one kind of artifact we hold for ChEMBL. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
APIs 16
Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.
Individual APIs this provider publishes, each with its own machine-readable definition.
ChEMBL Activity API
Activity values recorded in assays, linking molecules to targets with quantitative bioactivity measurements.
ChEMBL Assay API
Experimental protocols and result details from source documents and datasets.
ChEMBL ATC Classification API
WHO Anatomical Therapeutic Chemical classification for drugs.
ChEMBL Binding Site API
Target binding site definitions used in assays.
ChEMBL Cell Line API
Cell line information used in assays.
ChEMBL Compound Record API
Occurrence of a compound in a specific source document.
ChEMBL Document API
Source documents and datasets from which assay data is derived.
ChEMBL Drug API
Approved drug information including applicants, patent numbers, and research codes.
ChEMBL Drug Indication API
Drug-disease associations with clinical trial and regulatory references.
ChEMBL Drug Warning API
Safety information for withdrawn or black-box warned drugs.
ChEMBL Mechanism API
Mechanism of action information for approved drugs.
ChEMBL Molecule API
Chemical molecules including properties, structural representations, synonyms, and drug-like properties.
ChEMBL Similarity API
Molecule similarity searching using Tanimoto coefficient.
ChEMBL Status API
API operational status and ChEMBL database version information.
ChEMBL Substructure API
Molecular substructure searching.
ChEMBL Target API
Protein and non-protein targets defined in assays.
Scroll within the panel for all 16 ·
Pricing Plans 1
Pricing is part of the interface. Machine-readable plans tell you what a tier costs and includes before you commit — one of the six things the Kin Score reads for commercial clarity.
Published pricing tiers and plan structures.
Plans
PLANSRate Limits 1
Rate limits are the difference between a demo that works and a production integration that doesn't fall over. Publishing them is an operational-transparency signal — and a hard requirement for any agent that plans its own throughput.
Documented rate limits and quota policies.
Rate Limits
RATE LIMITSFinOps 1
Cost, billing, and metering signals let a buyer model the financial operations of an API before it's live. We profile them for the same reason we profile pricing: the money is part of the contract.
Cost, billing, and metering signals for API financial operations.
Finops
FINOPSSpectral Rules 1
Governance rulesets we run against this provider's specs — the automated checks behind parts of the score. Profiling them makes the quality bar explicit and re-runnable, not a matter of opinion.
ChEMBL API Rules
SPECTRALJSON Schema 3
Standalone JSON Schema definitions describe the data models behind the API. We profile them so the shapes are validatable on their own — useful long after a single request is forgotten.
Standalone JSON Schema definitions for this provider's data models.
Examples 3
Real request and response payloads are what turn a spec from abstract into obvious — and they're one of the twelve things an agent needs to call an API correctly on the first try.
Example request and response payloads for these APIs.
Security Posture 1
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Agentic Access 1
An x-agentic-access contract marks which operations are safe for an agent to run on its own and which need a human in the loop. It is the difference between an API an agent can use and one it can use safely.
Recommended x-agentic-access execution contracts for AI agents.
Resources
Every other property we hold for ChEMBL — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
Agent Surfaces 1
MCP servers, agent skills, and machine-readable catalogs
Design & Contract 1
Pagination, idempotency, versioning, errors, and events
Build 1
SDKs, sample code, and the tooling you integrate with
Access & Security 2
Authentication, authorization, and security posture
Operate 1
Status, limits, changes, and where to get help
Commercial 2
Pricing, plans, and the legal terms of use
Other 2
Properties that don't map to a standard resource type
← All providers · Data indexed from github.com/api-evangelist/chembl · machine-readable index on apis.io