Wikidata Server

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Overview

Wikidata's knowledge graph — entity search and lookup over the REST API v1, graph traversal via SPARQL against the Query Service, batch label resolution through MediaWiki, and external identifier resolution (DOI, PMID, ORCID, OpenAlex, IMDb). Search, fetch, and traverse entities from any MCP client. Runs as a stdio process, a local Streamable HTTP server, or the public hosted endpoint above.

Tools

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.)

Resources

Resource	Description
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.

Capability reference

wikidata_search_entities _tool

• 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 _tool

• 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 _tool

• 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 _tool

• 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 _tool

• 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 _tool

• Full graph power over the Wikidata Query Service (Blazegraph): 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 _tool

• 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

---

wikidata://entity/{id} _resource

• Compact markdown summary — labels (all languages), English description, instance-of (P31), enwiki Wikipedia link, image (P18), and statement count
• Returned as text/markdown; for full entity data, use wikidata_get_entity
• id is a Q-ID or P-ID, the same identifiers the tools take

Features

Built on @cyanheads/mcp-ts-core: stdio and Streamable HTTP transports, pluggable auth (none / jwt / oauth), swappable storage (in-memory, filesystem, Supabase, Cloudflare KV/R2/D1), structured logging with optional OpenTelemetry tracing.

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 (WIKIDATA_USER_AGENT)
• Separate timeout configuration for REST and SPARQL endpoints (WIKIDATA_REST_TIMEOUT_MS, WIKIDATA_SPARQL_TIMEOUT_MS)

Agent-friendly output:

• All tools echo relevant input parameters in the response for traceability
• wikidata_get_labels designed to follow SPARQL result sets — run the query, then humanize in one call
• wikidata_resolve_external_id returns multipleMatches instead of a false null when a Wikidata data-integrity issue puts duplicate claims on one external ID
• Oversized entities and statement sets return a kind: "outline" payload — field/property sizes plus a retrieval_notice naming the exact re-call — instead of a truncated or oversized response

Getting started

Public Hosted Instance

A public instance is available at https://wikidata.caseyjhand.com/mcp — no installation required. Point any MCP client at it via Streamable HTTP:

{
  "mcpServers": {
    "wikidata-mcp-server": {
      "type": "streamable-http",
      "url": "https://wikidata.caseyjhand.com/mcp"
    }
  }
}

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 v1.4.0 or higher (or Node.js ≥ 24.0.0).

Installation

1. Clone the repository:

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

2. Navigate into the directory:

cd wikidata-mcp-server

3. Install dependencies:

bun install

4. Configure environment:

cp .env.example .env
# edit .env and set any overrides

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_SESSION_MODE	HTTP session mode: stateful, stateless, or auto. The framework's auto default resolves to stateful; this server explicitly selects stateless.	stateless
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

See .env.example for the full list of optional overrides.

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
  

Docker

docker build -t wikidata-mcp-server .
docker run --rm -p 3010:3010 wikidata-mcp-server

The Dockerfile defaults to HTTP transport, stateless session mode, and logs to /var/log/wikidata-mcp-server. OpenTelemetry peer dependencies are installed by default — build with --build-arg OTEL_ENABLED=false to omit them.

Project structure

Directory	Purpose
src/index.ts	createApp() entry point — registers tools and resources, inits services.
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
• Wrap external API calls: validate raw → normalize to domain type → return output schema; never fabricate missing fields

Contributing

Issues are welcome. Run checks and tests before submitting:

bun run devcheck
bun run test

License

Apache-2.0 — see LICENSE for details.