National Center for Biotechnology Information (NCBI)
The National Center for Biotechnology Information (NCBI) provides a suite of free, publicly accessible REST APIs for querying and retrieving biological and biomedical data. Offerings include the Entrez Programming Utilities (E-utilities) for searching and fetching records across 38 databases including PubMed, GenBank, Gene, and Taxonomy; the BLAST URL API for homology sequence searching; the NCBI Datasets API for downloading genomic, gene, and taxonomy data; and PubChem APIs for chemical compound data. PMC developer tools provide Open Access article retrieval, metadata harvesting, identifier conversion, and citation export.
Real signal across most facets with visible, nameable gaps — the contract exists but is thin, or the portal is good while governance and commercial terms are absent.
API Evangelist profiles National Center for Biotechnology Information (NCBI) the way a machine reads it — 48 machine-readable artifacts across 14 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 — National Center for Biotechnology Information (NCBI) scores 46.8/100 (developing), 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 National Center for Biotechnology Information (NCBI)
Each block below is one kind of artifact we hold for National Center for Biotechnology Information (NCBI). 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 14
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.
NCBI Entrez E-utilities API
The Entrez Programming Utilities (E-utilities) are the public API to the NCBI Entrez system, providing access to over 38 Entrez databases including PubMed, GenBank (Nuccore), Ge...
NCBI BLAST URL API
The BLAST (Basic Local Alignment Search Tool) URL API allows developers to submit nucleotide and protein sequence homology searches via HTTPS, poll for job status, and retrieve ...
PubChem PUG REST API
The PubChem Power User Gateway (PUG) REST API provides programmatic access to PubChem's chemical compound, substance, and bioassay data. Developers can retrieve compound propert...
PMC Open Access API (OA Service)
The PubMed Central Open Access API retrieves citation data, licensing details, and FTP download locations for Open Access articles in the PMC archive. Queries accept a PMC ident...
PMC ID Converter API
The PMC ID Converter API translates between PubMed Central identifiers (PMCID), PubMed identifiers (PMID), Manuscript IDs, and Digital Object Identifiers (DOI). Batch conversion...
PMC OAI-PMH Service
The PMC OAI-PMH (Open Archives Initiative Protocol for Metadata Harvesting) service allows bulk harvesting of metadata for all items in the PMC archive and full-text content for...
National Center for Biotechnology Information (NCBI) BioSample API
#### Options to download BioSample data. This BioSample service allows you to get BioSample data as a data report.
National Center for Biotechnology Information (NCBI) Gene API
#### Options to download gene data, including the associated sequence and metadata. These gene services allow you to get gene metadata as a data report or download gene, transcr...
National Center for Biotechnology Information (NCBI) Genome API
#### Options to download assembled genome data, including the associated sequence, annotation and metadata. These genome services allow you to get genome metadata as a data repo...
National Center for Biotechnology Information (NCBI) Organelle API
#### Options to download RefSeq organelle genome data, including the associated sequence and metadata. These organelle services allow you to get RefSeq organelle genome metadata...
National Center for Biotechnology Information (NCBI) Prokaryote API
#### Options to download prokaryote gene data, including the associated sequence and metadata. These gene services allow you to download gene and protein sequence, and metadata ...
National Center for Biotechnology Information (NCBI) Taxonomy API
#### Options to download taxonomy data. These taxonomy services allow you to get taxonomy data as a data report or download taxonomy data as a taxonomy data package, for taxonom...
National Center for Biotechnology Information (NCBI) Version API
#### Retrieve the current version of all NCBI Datasets services. NCBI Datasets services follow the [Semantic Versioning 2.0.0 Schema](https://semver.org/spec/v2.0.0.html).
National Center for Biotechnology Information (NCBI) Virus API
#### Options to download virus genome data, including the associated sequence and metadata. These virus services allow you to get virus genome metadata as a data report or downl...
Scroll within the panel for all 14 ·
Pricing Plans 7
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.
Blast
PLANSDatasets
PLANSE Utilities
PLANSPmc Id Converter
PLANSPmc Oa
PLANSPmc Oai Pmh
PLANSPubchem Pug Rest
PLANSScroll within the panel for all 7 ·
Rate Limits 7
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.
Blast
RATE LIMITSDatasets
RATE LIMITSE Utilities
RATE LIMITSPmc Id Converter
RATE LIMITSPmc Oa
RATE LIMITSPmc Oai Pmh
RATE LIMITSPubchem Pug Rest
RATE LIMITSScroll within the panel for all 7 ·
FinOps 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.
Overview
FINOPSSemantic Vocabularies 2
JSON-LD contexts give the data shared meaning across APIs. We profile them because semantics are what let a machine reconcile 'customer' here with 'customer' somewhere else.
JSON-LD contexts and semantic vocabularies used across these APIs.
Ncbi Context
JSON-LDNcbi Provider Context
JSON-LDSpectral 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.
JSON Schema 8
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.
v2AssemblyDatasetRequest
JSON SCHEMAv2AssemblyLinksReply
JSON SCHEMAv2DownloadSummary
JSON SCHEMAv2GeneDatasetRequest
JSON SCHEMAv2OrthologRequest
JSON SCHEMAv2TaxonomyDatasetRequest
JSON SCHEMAv2TaxonomyNode
JSON SCHEMAv2VirusDatasetRequest
JSON SCHEMAScroll within the panel for all 8 ·
Examples 5
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.
Gene Accession Report
EXAMPLEGene Ortholog Report
EXAMPLETaxonomy Name Report
EXAMPLEVirus Genome Download
EXAMPLESecurity Posture 2
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 National Center for Biotechnology Information (NCBI) — 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.
Get Started 1
Portal, sign-up, and the first successful call
Agent Surfaces 1
MCP servers, agent skills, and machine-readable catalogs
Access & Security 3
Authentication, authorization, and security posture
Learn 1
Tutorials, courses, talks, and written guidance
Operate 2
Status, limits, changes, and where to get help
Commercial 2
Pricing, plans, and the legal terms of use
Company 2
The organization behind the API
← All providers · Data indexed from github.com/api-evangelist/ncbi · machine-readable index on apis.io