STRING MCP server

Which servers in the official MCP registry are STRING's own, whether they answer, and what they offer. A program checked each of these, nobody copied them from a product page.

read 2026-10-15

← Back to STRING

Whose server it is

Registry nameorg.string-db/string-mcpverified in the MCP registry

The registry name sits under string-db.org. The registry only lets a publisher use that namespace after proving control of the domain through DNS or HTTP.

When we asked itchecked 2026-10-15

Stateanswerschecked 2026-10-15
Tools17
Server calls itselfSTRING Database MCP Server
Server version2.14.7
Protocol version2025-06-18

On 2026-10-15 the server answered initialize and tools/list without a sign-in. First answer in 208 ms.

Should an agent connect itNot proven either way yet

Whether its tools do the product's job has not been judged yet.

Once connected

For "look up a protein's interaction network by name", the likely first call is string_resolve_proteins.
string_create_file change data without a sign-in: anyone with the address can call them.

Said by rules from the measurements above. The likely first call is a model's pick from the tool list; read its description before relying on it.

Measured dailydaily checks: 8, the first on 2026-10-19

INITE MCP score61 of 100answers 100 · definitions 83 · context 70 · use 23 · lowered by the warning signs below
Use7 GitHub stars
Answered100% of days8 of 8 daily checks
Median first answer536 ms
Space in an agent's context≈ 9,177 tokensthe definitions of all its tools (17), which an agent carries on every turn
Tool definitionsB · 83 of 100
Typed results17 of 17 toolsdeclared outputSchema: results come typed, read once

Not saying whether it only reads or can destroy: 17 of 17

What an agent can do with it

can do · look up a protein's interaction network by name
not sure · run enrichment analysis on a ranked protein list
not sure · build an interaction network from protein sequences

Each of the product's use cases, put to Jev against this server's tool list: can an agent do it with these tools?

Worth a look

Tools that change data, on a server that answers without a sign-in: string_create_file

A program checks the server once a day: initialize and tools/list, no model. Tokens are the definitions' length at about four characters a token. The grade averages six checks of every tool's name, description, schema and annotations; it says how well the tools are described, not whether they work. The score weighs what was measured and nothing else: answering (30%), doing the product's job (25%), definitions (20%), context (10%) and use (15%). A part that was not measured is left out, and a hidden instruction caps the score at 40. The state of vendors' MCP servers: method and numbers →

Tools it offers17 tools · read 2026-10-15

string_resolve_proteins
Maps one or more protein identifiers to their corresponding STRING metadata, including: gene symbol, description, sequence, domains, species, and internal STRING ID. This method is useful for translating raw identifiers into readable…
string_interactions_query_set
Retrieves the interactions between the query proteins. Use this method only when you specifically need to list the interactions between all proteins in your query set. - For a **single protein**, the network includes that protein and its…
string_all_interaction_partners
Retrieves all interaction partners for one or more proteins from STRING. This tool returns all known interactions between your query protein(s) and **any other proteins in the STRING database**. - Use this when asking **“What does TP53…
string_visual_network
Retrieves a URL to a **STRING interaction network image** for one or more proteins. - For a single protein: includes the protein and its top 10 most likely interactors. - For multiple proteins: includes all known interactions **within the…
string_network_clustering
Performs **network clustering** on a STRING interaction network and returns a network image URL, an interactive STRING network URL, and details about each detected cluster. Provide a table with each detected cluster’s color…
string_network_link
Retrieves a stable URL to an interactive STRING network for one or more proteins. - For a single protein: includes the protein and its top 10 most likely interactors. - For multiple proteins: includes all known interactions **within the…
string_homology
Retrieves pairwise protein similarity scores (Smith–Waterman bit scores) for the query proteins. - If no target species (`species_b`) is provided, results are intra-species (within the query species). - To retrieve homologs in other…
string_interaction_evidence
Retrieves direct links to STRING evidence pages for protein–protein interaction pairs. Use this tool only when a STRING evidence page/link is needed. To determine whether an interaction is supported, use `string_interactions_query_set`…
string_enrichment
This tool retrieves functional enrichment for a set of proteins using STRING. - If queried with a single protein, the tool expands the query to include the protein’s 10 most likely interactors; enrichment is performed on this set, not the…
string_functional_annotation
This tool retrieves curated functional annotations for a set of proteins. Each input protein is mapped to known biological terms from ontologies, pathway databases, tissues, compartments and domains — such as Gene Ontology (GO), KEGG, and…
string_enrichment_image_url
Retrieves a STRING enrichment figure (image URL) for a set of proteins. For the enriched terms and FDR values, use `string_enrichment`. - Each figure shows a single enrichment category; call again with another `category` to show a…
string_ppi_enrichment
This tool tests if your network is enriched in protein-protein interactions compared to the background proteome-wide distribution (i.e., if your proteins are more functionally connected than expected by chance). - The enrichment is…
string_proteins_for_term
Retrieve proteins annotated with a functional term or descriptive text in a single species. You can query for tissues, compartments, diseases, processes, pathways, and domains. IMPORTANT: For cross-species comparisons, run this tool…
string_sequence_search
Searches the STRING database using **amino acid sequences** to identify matching proteins. - Accepts a single sequence or multiple sequences in FASTA format. - Returns the most similar STRING protein(s) for the specified species, based on…
string_query_species
Search for species or clades available in STRING by free-text query and return their NCBI taxonomy IDs. - Use this when the user asks which species or clades are present in STRING, or when you need the correct NCBI taxon ID to pass to…
string_create_file
Creates a downloadable file for STRING-derived results. Use this tool when the user explicitly asks to download, save, export, or receive a file containing STRING data, tables, protein lists, enrichment results, networks, etc. When a…
string_help
Provides explanatory text for STRING features and limitations. Use this tool when the user question involves: - What is STRING is or how to use the tool (how_to_use_string, cytoscape) - functionality not available via MCP tools (e.g. GSEA…

How to connect

Add the server to your MCP client config. Claude Desktop, Cursor and most other clients read this shape:

{
  "mcpServers": {
    "string-mcp": {
      "type": "http",
      "url": "https://mcp.string-db.org/"
    }
  }
}

Add it

Claude Code, in a terminal

claude mcp add --transport http string-db https://mcp.string-db.org/

Add to Cursor Add to VS Code

claude.ai, ChatGPT and other clients: add https://mcp.string-db.org/ as a custom connector in the settings.

Each line is something a program found when it went looking: the registry entry, the server's own answer, a spec that parses. A missing line means we did not find it, not that it does not exist.