wikidata-mcp-server

<div align="center"> <h1>@cyanheads/wikidata-mcp-server</h1> <p><b>Search and fetch Wikidata entities, execute SPARQL queries, and resolve external identifiers via MCP. STDIO or Streamable HTTP.</b> <div>7 Tools • 1 Resource</div> </p> </div>

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Public Hosted Server: https://wikidata.caseyjhand.com/mcp

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Tools

7 tools for working with Wikidata's knowledge graph:

| Tool | Description | |:---|:---| | wikidata_search_entities | Search for items or properties by text query, returning QIDs/PIDs with labels, descriptions, and match metadata | | wikidata_get_entity | Fetch a full entity by QID or PID with optional field and language filtering | | wikidata_get_labels | Batch-resolve up to 50 QIDs or PIDs to human-readable labels and descriptions | | wikidata_get_statements | Fetch property claims for an entity with qualifier detail and QID label resolution | | wikidata_get_sitelinks | Fetch Wikipedia and Wikimedia project article URLs for a Wikidata item | | wikidata_sparql_query | Execute a SPARQL SELECT query against the Wikidata Query Service | | wikidata_resolve_external_id | Look up a Wikidata entity by an external identifier (DOI, PubMed ID, ORCID, OpenAlex ID, etc.) |

wikidata_search_entities

Search Wikidata for items or properties by text query.

• Searches labels, aliases, and descriptions
• type="item" for real-world concepts (people, places, works); type="property" for predicate P-IDs
• Language-aware results (BCP 47 language codes)
• Offset-based pagination, up to 50 results per call
• Returns match metadata indicating whether the hit was on a label or alias

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wikidata_get_entity

Fetch a Wikidata entity by QID or PID with field selection.

• Q-IDs (e.g. Q76) fetch items; P-IDs (e.g. P31) fetch properties — endpoint routing is automatic
• fields parameter selects labels, descriptions, aliases, statements, or sitelinks
• fields narrows the upstream fetch, not just the response — Q76 is 344,114 bytes whole, 6,703 for labels alone
• languages parameter filters multilingual maps to specific language codes, client-side (the entity endpoint takes no language parameter)
• An entity too large to inline returns a field-category outline with byte sizes instead of the data — follow its retrieval_notice: it names a literal fields set already measured to fit (category sizes are additive, so requesting every name listed would overflow again), defers the remainder to a further call, and redirects a category too large to deliver whole (statements or sitelinks on a major item) to the tool that can narrow it

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wikidata_get_labels

Batch-resolve QIDs/PIDs to human-readable labels and descriptions.

• Up to 50 IDs per call, batched via the MediaWiki wbgetentities API
• Supports multiple language codes per request
• Reports found count and notFound IDs for partial-result handling
• Designed for the common agent pattern: run a SPARQL query, then humanize the QID results

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wikidata_get_statements

Fetch property claims for a Wikidata entity with full qualifier and reference detail.

• properties parameter fetches only specific P-IDs — omit to return all statements
• Value QIDs are resolved to human-readable labels by default via a batched label call
• Set resolve_labels=false for raw QIDs only (faster, smaller payload)
• A statement set too large to inline returns an outline of the available P-IDs with byte sizes, largest first, instead of the statements — re-call with properties for the ones you need (unfiltered, Q30 carries 467 properties across 1,717 statements)
• Preferred-rank statements represent the most current values
• Designed for fact verification: "what does Wikidata say about this entity's {property}?"

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wikidata_get_sitelinks

Fetch Wikipedia and Wikimedia project article URLs for a Wikidata item.

• Maps site codes (e.g., enwiki) to article titles and URLs
• sites parameter filters to specific site codes
• wikis_only=true returns only Wikipedia links (excludes Wiktionary, Wikiquote, Wikisource, etc.)
• Major items can have 300+ sitelinks across languages
• Only Q-IDs (items) have sitelinks — P-IDs are not supported

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wikidata_sparql_query

Execute a SPARQL SELECT query against the Wikidata Query Service (Blazegraph).

• Full graph power: multi-hop traversals, aggregations, subqueries, OPTIONAL, FILTER, UNION, BIND
• Standard Wikidata prefixes (wd:, wdt:, p:, ps:, pq:, wikibase:, bd:) are auto-injected
• wikibase:label SERVICE auto-injected when language is set and the query uses ?<var>Label variables
• Results in SPARQL 1.1 JSON format: each binding is { type, value, "xml:lang"? }
• Hard server timeout is 60s; client-side timeout parameter (1–55s) applies earlier
• Rate-limited at 60 requests/min and 5 concurrent requests per IP

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wikidata_resolve_external_id

Look up a Wikidata entity by an external identifier.

• Common use cases: CrossRef DOI → QID (P356), PubMed PMID → QID (P698), ORCID → author QID (P496), OpenAlex ID → entity QID (P10283), IMDb ID (P345)
• Automatic value normalization: surrounding whitespace trimmed, resolver URL prefixes stripped (https://doi.org/, https://pubmed.ncbi.nlm.nih.gov/, https://orcid.org/), DOIs uppercased, PMID prefixes stripped, ORCID hyphens normalized
• The property's data type must be external-id — item-valued or media properties (e.g. P31, P18) are rejected rather than returning an empty match
• Returns match=null when not found (the Query Service lags the live wiki, so a null is not proof of absence)
• Returns multipleMatches when a Wikidata data integrity issue causes more than one entity to claim the same external ID
• Designed for cross-server joins with pubmed-mcp-server, crossref-mcp-server, and openalex-mcp-server

Resource

| Type | Name | Description | |:---|:---|:---| | Resource | wikidata://entity/{id} | Compact markdown summary of a Wikidata entity — labels, English description, instance-of, Wikipedia link, image, and statement count |

All resource data is also reachable via tools.

Features

Built on @cyanheads/mcp-ts-core:

• Declarative tool definitions — single file per tool, framework handles registration and validation
• Unified error handling across all tools
• Pluggable auth (none, jwt, oauth)
• Swappable storage backends: in-memory, filesystem, Supabase, Cloudflare KV/R2/D1
• Structured logging with optional OpenTelemetry tracing
• Runs locally (stdio/HTTP) from the same codebase

Wikidata-specific:

• Wikidata REST API v1 for entity and statement fetches — no SPARQL overhead for lookup operations
• MediaWiki wbgetentities API for efficient batch label resolution
• Wikidata Query Service (Blazegraph) for SPARQL with auto-injected prefix headers and label SERVICE
• Configurable User-Agent per Wikimedia policy
• Separate timeout configuration for REST and SPARQL endpoints

Agent-friendly output:

• wikidata_get_labels designed to follow SPARQL result sets — run the query, then humanize in one call
• wikidata_resolve_external_id handles DOI/PMID/ORCID normalization transparently, with multipleMatches for data integrity edge cases
• wikidata_get_statements resolves QID values to labels in the same call, with resolve_labels=false escape hatch for raw payloads
• All tools echo input parameters in the response for traceability

Getting started

Self-Hosted / Local

Add the following to your MCP client configuration file.

{
  "mcpServers": {
    "wikidata-mcp-server": {
      "type": "stdio",
      "command": "bunx",
      "args": ["@cyanheads/wikidata-mcp-server@latest"],
      "env": {
        "MCP_TRANSPORT_TYPE": "stdio",
        "MCP_LOG_LEVEL": "info"
      }
    }
  }
}

Or with npx (no Bun required):

{
  "mcpServers": {
    "wikidata-mcp-server": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@cyanheads/wikidata-mcp-server@latest"],
      "env": {
        "MCP_TRANSPORT_TYPE": "stdio",
        "MCP_LOG_LEVEL": "info"
      }
    }
  }
}

Or with Docker:

{
  "mcpServers": {
    "wikidata-mcp-server": {
      "type": "stdio",
      "command": "docker",
      "args": ["run", "-i", "--rm", "-e", "MCP_TRANSPORT_TYPE=stdio", "ghcr.io/cyanheads/wikidata-mcp-server:latest"]
    }
  }
}

For Streamable HTTP, set the transport and start the server:

MCP_TRANSPORT_TYPE=http MCP_HTTP_PORT=3010 bun run start:http
# Server listens at http://localhost:3010/mcp

Prerequisites

• Bun v1.3.0 or higher (or Node.js ≥ 24.0.0).

Installation

1. Clone the repository:

git clone https://github.com/cyanheads/wikidata-mcp-server.git

1. Navigate into the directory:

cd wikidata-mcp-server

1. Install dependencies:

bun install

Configuration

All configuration is validated at startup via Zod schemas. Key environment variables:

| Variable | Description | Default | |:---|:---|:---| | MCP_TRANSPORT_TYPE | Transport: stdio or http | stdio | | MCP_HTTP_PORT | HTTP server port | 3010 | | MCP_HTTP_ENDPOINT_PATH | HTTP endpoint path where the MCP server is mounted | /mcp | | MCP_PUBLIC_URL | Public origin override for TLS-terminating reverse-proxy deployments | none | | MCP_AUTH_MODE | Authentication: none, jwt, or oauth | none | | MCP_LOG_LEVEL | Log level (debug, info, notice, warning, error) | info | | MCP_GC_PRESSURE_INTERVAL_MS | Opt-in Bun-only forced-GC interval (ms). Try 60000 if heap growth is observed under HTTP load. | 0 (disabled) | | LOGS_DIR | Directory for log files (Node.js only) | <project-root>/logs | | STORAGE_PROVIDER_TYPE | Storage backend: in-memory, filesystem, supabase, cloudflare-kv/r2/d1 | in-memory | | WIKIDATA_USER_AGENT | User-Agent string for Wikimedia requests (policy requires a descriptive value) | wikidata-mcp-server/0.1 (https://github.com/cyanheads/wikidata-mcp-server) | | WIKIDATA_SPARQL_TIMEOUT_MS | Max wait for a SPARQL response in ms | 55000 | | WIKIDATA_REST_TIMEOUT_MS | Max wait for REST API responses in ms | 10000 | | OTEL_ENABLED | Enable OpenTelemetry | false |

Running the server

Local development

• Build and run the production version:

  # One-time build
  bun run rebuild

  # Run the built server
  bun run start:http
  # or
  bun run start:stdio

• Run checks and tests:

  bun run devcheck  # Lints, formats, type-checks, and more
  bun run test      # Runs the test suite

Project structure

| Directory | Purpose | |:---|:---| | src/mcp-server/tools | Tool definitions (*.tool.ts). Seven tools for entity lookup, statements, sitelinks, SPARQL, and external ID resolution. | | src/mcp-server/resources | Resource definitions. Entity summary resource. | | src/services/wikidata | Wikidata service layer — REST API client, SPARQL client, statement normalization, types. | | src/config | Server-specific environment variable parsing and validation with Zod. | | tests/ | Unit and integration tests, mirroring the src/ structure. |

Development guide

See CLAUDE.md for development guidelines and architectural rules. The short version:

• Handlers throw, framework catches — no try/catch in tool logic
• Use ctx.log for logging, ctx.state for storage
• Register new tools and resources in the createApp() arrays

Contributing

Issues and pull requests are welcome. Run checks and tests before submitting:

bun run devcheck
bun run test

License

Apache-2.0 — see LICENSE for details.