STRING

STRING is a protein-protein interaction network database providing scored associations between proteins across thousands of organisms. The REST API enables programmatic access to interaction scores, network visualizations, functional enrichment analysis, homology data, and protein annotations. STRING integrates data from genomic context, co-expression, text mining, biochemical and genetic experiments, and curated databases.

STRING publishes 7 APIs on the APIs.io network, including Annotation API, Enrichment API, Homology API, and 4 more. Tagged areas include Bioinformatics, Proteins, Genomics, Life Sciences, and Research.

The STRING catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.

🌐 Visit website 📡 Source on GitHub

35.6/100 thin ▬ flat Agent 21/100 agent aware Full breakdown ↓
scored 2026-08-20 · rubric v0.12.0

AccessFree

7 APIs

BioinformaticsProteinsGenomicsLife SciencesResearchOpen Data

Kin Score

Kin Score How this is scored →
scored 2026-08-20 · rubric v0.12.0

Composite quality — 35.6/100 · thin

Contract Quality 12.6 / 21

Developer Ergonomics 1.2 / 17

Access Clarity 6.7 / 17

Operational Transparency 2.3 / 11

Contract Governance 1.0 / 10

Discoverability 6.5 / 9

Regulatory Posture 2.8 / 15

Agent readiness — 21/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 0 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Regulatory Posture applies to this provider. Its tags matched the Health regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/string-db: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 7

Individual APIs this provider publishes, each with its own machine-readable definition.

Rate Limits 1

Documented rate limits and quota policies.

Rate Limits

2 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

JSON Schema 3

Standalone JSON Schema definitions for this provider's data models.

Examples 4

Example request and response payloads for these APIs.

Documentation 2

Reference material describing how the API behaves

UsageGuidelines

UsageGuidelines

APIDocumentation

APIDocumentation

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Commercial 1

Pricing, plans, and the legal terms of use

TermsOfService

TermsOfService

Other 2

Properties that don't map to a standard resource type

Licensing

Licensing

Downloads

Downloads

Source (apis.yml)

name: STRING
description: 'STRING is a protein-protein interaction network database providing scored associations between proteins across
  thousands of organisms. The REST API enables programmatic access to interaction scores, network visualizations, functional
  enrichment analysis, homology data, and protein annotations. STRING integrates data from genomic context, co-expression,
  text mining, biochemical and genetic experiments, and curated databases.

  '
specificationVersion: '0.23'
accessModel:
  pricing: free
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Free
  confidence: medium
  source:
  - plans
  generated: '2026-07-22'
  method: derived
image: https://string-db.org/images/logo/logo_medium.png
tags:
- Bioinformatics
- Proteins
- Genomics
- Life Sciences
- Research
- Open Data
url: https://string-db.org
apis:
- aid: string-db:string-db-annotation-api
  name: STRING Annotation API
  description: Functional annotations and term lookup
  humanURL: https://string-db.org/help/api/
  baseURL: https://string-db.org
  tags:
  - Annotation
  tags_raw:
  - annotation
  properties:
  - type: OpenAPI
    url: openapi/string-db-annotation-api-openapi.yml
  - type: Documentation
    url: https://string-db.org/help/api/
- aid: string-db:string-db-enrichment-api
  name: STRING Enrichment API
  description: Functional enrichment analysis
  humanURL: https://string-db.org/help/api/
  baseURL: https://string-db.org
  tags:
  - Enrichment
  tags_raw:
  - enrichment
  properties:
  - type: OpenAPI
    url: openapi/string-db-enrichment-api-openapi.yml
  - type: Documentation
    url: https://string-db.org/help/api/
- aid: string-db:string-db-homology-api
  name: STRING Homology API
  description: Protein homology and similarity scores
  humanURL: https://string-db.org/help/api/
  baseURL: https://string-db.org
  tags:
  - Homology
  tags_raw:
  - homology
  properties:
  - type: OpenAPI
    url: openapi/string-db-homology-api-openapi.yml
  - type: Documentation
    url: https://string-db.org/help/api/
- aid: string-db:string-db-identifiers-api
  name: STRING Identifiers API
  description: Map protein names and synonyms to STRING identifiers
  humanURL: https://string-db.org/help/api/
  baseURL: https://string-db.org
  tags:
  - Identifiers
  tags_raw:
  - identifiers
  properties:
  - type: OpenAPI
    url: openapi/string-db-identifiers-api-openapi.yml
  - type: Documentation
    url: https://string-db.org/help/api/
- aid: string-db:string-db-network-api
  name: STRING Network API
  description: Retrieve protein-protein interaction networks
  humanURL: https://string-db.org/help/api/
  baseURL: https://string-db.org
  tags:
  - Network
  tags_raw:
  - network
  properties:
  - type: OpenAPI
    url: openapi/string-db-network-api-openapi.yml
  - type: Documentation
    url: https://string-db.org/help/api/
- aid: string-db:string-db-utility-api
  name: STRING Utility API
  description: Utility endpoints (version, links, API key)
  humanURL: https://string-db.org/help/api/
  baseURL: https://string-db.org
  tags:
  - Utility
  tags_raw:
  - utility
  properties:
  - type: OpenAPI
    url: openapi/string-db-utility-api-openapi.yml
  - type: Documentation
    url: https://string-db.org/help/api/
- aid: string-db:string-db-valuesranks-api
  name: STRING Valuesranks API
  description: Values/Ranks GSEA-like enrichment (requires API key)
  humanURL: https://string-db.org/help/api/
  baseURL: https://string-db.org
  tags:
  - valuesranks
  properties:
  - type: OpenAPI
    url: openapi/string-db-valuesranks-api-openapi.yml
  - type: Documentation
    url: https://string-db.org/help/api/
common:
- type: DomainSecurity
  url: security/string-db-domain-security.yml
- type: TermsOfService
  url: https://string-db.org/cgi/info?footer_active_subpage=cookies
- type: Licensing
  url: https://string-db.org/cgi/access?footer_active_subpage=licensing
- type: UsageGuidelines
  url: https://string-db.org/cgi/access?footer_active_subpage=usage
- type: APIDocumentation
  url: https://string-db.org/help/api/
- type: Downloads
  url: https://string-db.org/cgi/download
modified: 2026-06-13
maintainers:
- FN: STRING Consortium
  url: https://string-db.org

STRING

APIs 7

Open Collections 8

Pricing Plans 1