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.
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:
  - name: STRING REST API
    description: >
      REST API for accessing protein-protein interaction networks, functional
      enrichment results, homology data, and annotation information from the
      STRING database. Supports multiple output formats including JSON, TSV,
      XML, and image formats.
    humanURL: https://string-db.org/help/api/
    baseURL: https://string-db.org
    version: "12.0"
    tags:
      - Protein Interactions
      - Network Biology
      - Functional Enrichment
      - Bioinformatics
    properties:
      - type: Documentation
        url: https://string-db.org/help/api/
      - type: OpenAPI
        url: https://string-db.org/help/api/
    contact:
      - FN: STRING Consortium
        url: https://string-db.org
    meta:
      security:
        - type: apiKey
          description: >
            API key required only for Values/Ranks Enrichment endpoints.
            Obtain via POST /api/json/get_api_key. All other endpoints
            are publicly accessible without authentication.
    endpoints:
      - name: Get STRING IDs
        method: GET
        path: /api/{format}/get_string_ids
        description: Map gene names, synonyms, or UniProt IDs to STRING identifiers
        parameters:
          - name: format
            in: path
            required: true
            description: Output format (tsv, tsv-no-header, json, xml)
          - name: identifiers
            in: query
            required: true
            description: Protein identifiers to map
          - name: species
            in: query
            required: false
            description: NCBI taxon ID (e.g. 9606 for human)
          - name: caller_identity
            in: query
            required: false
            description: Identifier for your application
      - name: Network Image or Interactions
        method: GET
        path: /api/{format}/network
        description: >
          Retrieve network image or interaction data for a set of proteins.
          Supports image formats (image, highres_image, svg) and data formats
          (tsv, json, xml, psi-mi, psi-mi-tab).
        parameters:
          - name: format
            in: path
            required: true
            description: Output format
          - name: identifiers
            in: query
            required: true
            description: Protein identifiers
          - name: species
            in: query
            required: false
            description: NCBI taxon ID
          - name: required_score
            in: query
            required: false
            description: Minimum interaction score threshold (0-1000)
          - name: network_type
            in: query
            required: false
            description: functional or physical
          - name: network_flavor
            in: query
            required: false
            description: evidence, confidence, or actions
          - name: add_color_nodes
            in: query
            required: false
            description: Number of additional colored nodes to add
          - name: add_white_nodes
            in: query
            required: false
            description: Number of additional white nodes to add
      - name: Get Network Link
        method: GET
        path: /api/{format}/get_link
        description: Generate a stable URL linking to a STRING network
        parameters:
          - name: format
            in: path
            required: true
            description: Output format (tsv, json)
          - name: identifiers
            in: query
            required: true
            description: Protein identifiers
          - name: species
            in: query
            required: false
            description: NCBI taxon ID
      - name: Interaction Partners
        method: GET
        path: /api/{format}/interaction_partners
        description: Retrieve all STRING interaction partners for input proteins
        parameters:
          - name: format
            in: path
            required: true
            description: Output format (tsv, tsv-no-header, json, xml)
          - name: identifiers
            in: query
            required: true
            description: Protein identifiers
          - name: species
            in: query
            required: false
            description: NCBI taxon ID
          - name: limit
            in: query
            required: false
            description: Maximum number of interaction partners to return
          - name: required_score
            in: query
            required: false
            description: Minimum interaction score threshold (0-1000)
          - name: network_type
            in: query
            required: false
            description: functional or physical
      - name: Homology
        method: GET
        path: /api/{format}/homology
        description: >
          Return Smith-Waterman bit scores between proteins in the input set
        parameters:
          - name: format
            in: path
            required: true
            description: Output format (tsv, tsv-no-header, json, xml)
          - name: identifiers
            in: query
            required: true
            description: Protein identifiers
          - name: species
            in: query
            required: false
            description: NCBI taxon ID
      - name: Best Homology
        method: GET
        path: /api/{format}/homology_best
        description: >
          Return best cross-species homology hits for input proteins
        parameters:
          - name: format
            in: path
            required: true
            description: Output format (tsv, tsv-no-header, json, xml)
          - name: identifiers
            in: query
            required: true
            description: Protein identifiers
          - name: species
            in: query
            required: false
            description: NCBI taxon ID (source species)
          - name: species_b
            in: query
            required: false
            description: NCBI taxon ID (target species)
      - name: Functional Enrichment
        method: GET
        path: /api/{format}/enrichment
        description: >
          Perform functional enrichment analysis for a set of proteins.
          Returns enriched GO terms, KEGG pathways, and other categories.
        parameters:
          - name: format
            in: path
            required: true
            description: Output format (tsv, tsv-no-header, json, xml)
          - name: identifiers
            in: query
            required: true
            description: Protein identifiers
          - name: species
            in: query
            required: false
            description: NCBI taxon ID
          - name: background_string_identifiers
            in: query
            required: false
            description: Custom background gene set identifiers
          - name: allow_pubmed
            in: query
            required: false
            description: Include PubMed term enrichment
      - name: Enrichment Figure
        method: GET
        path: /api/{format}/enrichmentfigure
        description: Generate a visual figure of enrichment results
        parameters:
          - name: format
            in: path
            required: true
            description: Image format (image, highres_image, svg)
          - name: identifiers
            in: query
            required: true
            description: Protein identifiers
          - name: species
            in: query
            required: false
            description: NCBI taxon ID
      - name: Functional Annotation
        method: GET
        path: /api/{format}/functional_annotation
        description: >
          Retrieve all functional annotations associated with input proteins
        parameters:
          - name: format
            in: path
            required: true
            description: Output format (tsv, tsv-no-header, json, xml)
          - name: identifiers
            in: query
            required: true
            description: Protein identifiers
          - name: species
            in: query
            required: false
            description: NCBI taxon ID
          - name: allow_pubmed
            in: query
            required: false
            description: Include PubMed annotations
      - name: Functional Terms
        method: GET
        path: /api/{format}/functional_terms
        description: >
          Retrieve details about specific functional terms (GO, KEGG, etc.)
        parameters:
          - name: format
            in: path
            required: true
            description: Output format (tsv, tsv-no-header, json, xml)
          - name: identifier
            in: query
            required: true
            description: Functional term identifier
          - name: category
            in: query
            required: false
            description: >
              Term category (Process, Function, Component, Keyword, KEGG,
              RCTM, Pfam, InterPro, SMART, NetworkNeighborAL, COMPARTMENTS,
              Tissue, Disease)
      - name: Gene Set Description
        method: GET
        path: /api/{format}/geneset_description
        description: Retrieve textual descriptions for functional gene sets
        parameters:
          - name: format
            in: path
            required: true
            description: Output format (tsv, tsv-no-header, json, xml)
          - name: identifiers
            in: query
            required: true
            description: Protein identifiers
          - name: species
            in: query
            required: false
            description: NCBI taxon ID
      - name: PPI Enrichment
        method: GET
        path: /api/{format}/ppi_enrichment
        description: >
          Test whether interactions in a protein set are more significant
          than expected by random chance
        parameters:
          - name: format
            in: path
            required: true
            description: Output format (tsv, json, xml)
          - name: identifiers
            in: query
            required: true
            description: Protein identifiers
          - name: species
            in: query
            required: false
            description: NCBI taxon ID
          - name: required_score
            in: query
            required: false
            description: Minimum interaction score threshold (0-1000)
          - name: network_type
            in: query
            required: false
            description: functional or physical
      - name: Get API Key
        method: POST
        path: /api/json/get_api_key
        description: >
          Obtain an API key required for Values/Ranks Enrichment endpoints
        parameters:
          - name: caller_identity
            in: body
            required: true
            description: Identifier for your application
      - name: Submit Values/Ranks Enrichment Job
        method: POST
        path: /api/json/valuesranks_enrichment_submit
        description: >
          Submit a GSEA-like enrichment analysis on a ranked list of proteins
          with associated values. Accepts up to 1000 concurrent jobs.
        parameters:
          - name: api_key
            in: body
            required: true
            description: API key obtained via get_api_key endpoint
          - name: identifiers
            in: body
            required: true
            description: Tab-separated protein-value pairs
          - name: species
            in: body
            required: true
            description: NCBI taxon ID
          - name: ge_fdr
            in: body
            required: false
            description: False discovery rate threshold (default 0.01)
          - name: caller_identity
            in: body
            required: false
            description: Identifier for your application
      - name: Check Values/Ranks Enrichment Status
        method: GET
        path: /api/json/valuesranks_enrichment_status
        description: Check the status of a submitted Values/Ranks enrichment job
        parameters:
          - name: api_key
            in: query
            required: true
            description: API key
          - name: job_id
            in: query
            required: true
            description: Job ID from submission response
      - name: Remove Values/Ranks Enrichment Job
        method: GET
        path: /api/json/valuesranks_enrichment_remove
        description: Remove a completed Values/Ranks enrichment job
        parameters:
          - name: api_key
            in: query
            required: true
            description: API key
          - name: job_id
            in: query
            required: true
            description: Job ID to remove
      - name: Version
        method: GET
        path: /api/{format}/version
        description: Return the current STRING database version and stable address
        parameters:
          - name: format
            in: path
            required: true
            description: Output format (tsv, json, xml)
common:
  - 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