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cyanheads/wikipedia-mcp-server

v0.3.0Apache-2.0

Search Wikipedia articles, read summaries and full text, target sections, list an article's cited references, find nearby pages, and list language editions via MCP. STDIO or Streamable HTTP.

Version License Docker MCP SDK npm TypeScript Bun

Install in Claude Desktop Install in Cursor Install in VS Code

Framework

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


Overview

Wikipedia in any language edition. Search articles, read summaries or just the sections you need, list the footnotes an article cites, find geotagged pages near a coordinate, and list an article's language editions. Ships the wikipedia-guide agent skill (skill://wikipedia-guide/SKILL.md), which MCP clients read for the gates that span tools: switching editions, disambiguation pages, section numbers versus section_index, and what to check before reporting something absent.

Tools

ToolDescription
wikipedia_search_articlesFull-text search across Wikipedia, returning ranked results with short descriptions, Wikidata QIDs, plain-text snippets, and page IDs, plus Wikipedia's spelling suggestion.
wikipedia_get_summaryShort summary for any article — plain text, Wikidata QID, description, thumbnail URL, page type, canonical URL, revision, and coordinates.
wikipedia_get_articleFull article or a targeted section as clean plain text, with section markers preserved, the canonical URL, and the revision it was read from.
wikipedia_get_sectionsTable of contents with section_index values for targeted section reads.
wikipedia_search_nearbyGeotagged Wikipedia articles within a radius of a WGS 84 coordinate, sorted by distance, with short descriptions and Wikidata QIDs.
wikipedia_get_languagesAll language editions available for an article, with titles and URLs, or just the editions you ask for.
wikipedia_get_referencesThe footnotes an article cites, in document order, with each footnote's text, external links (archive copies included), and DOIs, plus the full citations that short citations point to.

Capability reference

wikipedia_search_articles tool

  • Free-text query (an empty one fails with empty_query), positive integer limit (default 10, clamped to 50), and offset paging, passing back enrichment nextOffset. Only a clamped call carries requestedLimit, appliedLimit, and a clamp notice. Wikipedia serves no result past the 10,000th: an offset at or beyond it fails with offset_too_large, and a page ending on that window carries enrichment truncated
  • CirrusSearch operators include incategory:"1648 treaties", morelike:Peace of Westphalia, intitle:Python, hastemplate:Infobox, and insource:Python (support depends on the installation). sort defaults to relevance; alternatives are last_edit_desc, create_timestamp_desc, incoming_links_desc, and title_natural_asc. Enrichment echoes sort; keep it and query unchanged when paging
  • Each result carries a plain-text snippet, page ID, word count, and — when the article has them — its short description and Wikidata QID (wikibase_item); enrichment suggestion carries Wikipedia's spelling correction (einstien → einstein)
  • Invalid or over-complex insource:/…/ and intitle:/…/ regexes fail once with invalid_query, the upstreamCode, and guidance to correct or simplify the regex or remove the operator. A busy regex search remains retryable

wikipedia_get_summary tool

  • Takes a title; returns the REST summary extract — a fragment from the start of the lead (wikipedia_get_article with section_index: 0 reads the whole lead) — plus the short description, thumbnail URL, Wikidata QID (wikibase_item), and, for a geotagged article, latitude / longitude to pass straight to wikipedia_search_nearby
  • page_type discriminates standard / disambiguation / no-extract (on disambiguation, re-query with wikipedia_search_articles); url, revision_id, and last_modified name the revision read, and ?oldid=<revision_id> is a permanent link to it
  • An existing page without a summary extract succeeds with metadata, an empty extract, and guidance to open the canonical URL or try section_index: 0. Namespace pages may contain documentation rather than article prose. An empty description is absent; a missing title still fails with not_found

wikipedia_get_article tool

  • Without section_index: the full article with == Section == markers, or a section outline (truncated: true) when it exceeds WIKIPEDIA_ARTICLE_OVERFLOW_BYTES (default 80,000 bytes). With a section_index from wikipedia_get_sections (0 is the lead): that section plus its nested subsections
  • Outline entries include verified section_index values where available, including 0 for the lead. Ambiguous or unindexed headings retain the section-list fallback. TOC verification gets one short attempt; unavailable verification is disclosed
  • Redirects expose redirected_from and, for a section target, redirect_section. A full read remains full and includes targeted-read guidance; an explicit section_index, including 0, takes precedence
  • Every read returns url and revision_id (?oldid=<revision_id> is a permanent link to the text read); a full read, outline included, also returns last_modified. With WIKIPEDIA_BASE_URL set, a section read omits url
  • Section reads render phylogenetic clade trees as fenced, indented branches, pairing each row’s label with its leaf and preserving unnamed forks. An unparseable tree leaves [table omitted: unparseable clade]; trees have no table_index
  • Section reads also carry data tables as pipe-delimited rows and infoboxes as label: value lines, which the full-article extract strips; a table over 40,000 rendered bytes leaves a [table omitted: N rows (table T)] marker. Pass table_index: T with the section to read that table in complete row pages, then follow next_cursor as cursor with the same inputs. Continuations read the first page’s revision; caption and header appear once. Each page's table text fits 40,000 UTF-8 bytes on both surfaces, except an indivisible oversized row or first-page caption/header returned alone with oversized_row: true

wikipedia_get_sections tool

  • Takes a title; returns section titles, heading levels, hierarchical numbering (e.g. "2.1"), and the section_index to pass to wikipedia_get_article — the first entry is the lead (index: 0, titled Introduction)
  • Heading titles use the article renderer’s script, formula, whitespace and single-pass entity normalization, so CO₂ stays identical across the section list, article reads and verified outline entries
  • Fails with no_sections on a stub or very short article — read it with wikipedia_get_article instead
  • Redirect aliases expose redirected_from and optional redirect_section; redirect_section_index appears only when a unique anchor matches a real numeric TOC index

wikipedia_search_nearby tool

  • latitude −90…90 / longitude −180…180 (WGS 84), radius_meters 10–10,000 (default 1000), and positive integer limit (default 10, clamped to 500), with no pagination past limit; enrichment truncated flags more matches than limit allowed — at 500, Wikipedia's ceiling, sweep narrower radii instead. Only a clamped call carries requestedLimit, appliedLimit, and a clamp notice
  • Returns articles sorted by distance_meters, with coordinates, short description, and Wikidata QID (wikibase_item). Each is placed by the article's own GeoData coordinate tag, not its Wikidata item's coordinate, so a mistagged article appears where the tag puts it

wikipedia_get_languages tool

  • Takes a title; returns each edition's language_code, edition_code, article title, and URL, plus source_title, the resolved title. Pass edition_code — not language_code — as language on other tools; the two can differ (gsw vs als)
  • editions narrows the list to the codes asked for: codes with no article come back under missing, and total_languages stays the unfiltered count. Fails with no_other_languages when the article has no translations; a filter matching nothing is an empty list, not a failure

wikipedia_get_references tool

  • Takes a title; returns references[] in document order across every reference list, each with id, label (the in-text marker), group (a notes list such as lower-alpha, absent for the main list), text, urls (archive copies included), and dois (from doi.org links, percent-decoded). total_references counts the footnotes on all pages. wikipedia_get_article drops footnote markers and reference lists
  • A short citation such as "Galinsky 2012, pp. 75–76" carries work_ids, and works on the same page holds the full citations they name, each once. Bibliography and further-reading entries no footnote points to are not listed — read those sections with wikipedia_get_article
  • Each page holds whole footnotes within 40,000 UTF-8 bytes on both surfaces; follow next_cursor as cursor with the same title and language. Continuations read the first page's revision_id, and a cursor past the last footnote fails invalid_cursor. An unreadable pinned revision fails revision_unavailable. An article with no footnotes returns an empty list with a notice, not an error

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.

Wikipedia-specific:

  • Dual API integration — MediaWiki REST API (/api/rest_v1/) for summaries, Action API (/w/api.php) for search, full text, sections, geo search, and language links
  • Retry and backoff on every required request, including the transient refusals (search too busy, rate-limited, read-only) the Action API returns inside an HTTP 200 body, with an upstream Retry-After honored and each request's retries bounded at 30 s. The best-effort description lookup on search results gets one short attempt; User-Agent header per Wikimedia API policy
  • Every read path renders HTML through one renderer to the same plain-text shape — == Heading == markers, one list item per line, superscripts kept, code fenced: the full article from the Action API's HTML extract, a section from the parser's own HTML for that section, the summary from the REST extract_html. A section read additionally carries data tables, infoboxes, and the lists inside layout tables, none of which the extract carries. Footnote markers, reference lists, and the hidden Citation Style 1 maintenance messages (CS1 maint: …) are dropped on every path; wikipedia_get_references returns the footnotes
  • Per-call language parameter on every tool (default en) — all Wikipedia language editions accessible in a single session; every title read follows redirects
  • Language validation against a live edition registry built from the MediaWiki action=sitematrix endpoint (cached 24h) — catches structurally valid but nonexistent editions before they cause timeouts

Agent-friendly output:

  • page_type on summaries discriminates standard / disambiguation / no-extract — no string parsing needed
  • wikibase_item (Wikidata QID) on summaries and on search and nearby results enables direct cross-referencing with wikidata-mcp-server
  • Article text, snippets, and titles are backslash-escaped on the way into the markdown content[] render, so an article that writes about markup or markdown syntax reads as itself instead of being interpreted by the client; structuredContent carries the same text unescaped. Fenced code blocks and table-row delimiters pass through unescaped, while table cells stay escaped
  • section_index on table-of-contents entries links directly to the targeted-read parameter on wikipedia_get_article, index 0 included
  • Titles MediaWiki cannot name a page with — < > [ ] { }, the | multi-title separator, percent escapes, magic tildes, relative paths — are refused before any request, with invalid_title; a trailing #fragment is accepted and resolves normally
  • Recovery hints on every error type — callers get actionable next steps (e.g., "use wikipedia_search_articles to find the correct title")

Getting started

Connect to the hosted instance, no install:

claude mcp add --transport http wikipedia-mcp-server https://wikipedia.caseyjhand.com/mcp

Or run it locally:

claude mcp add wikipedia-mcp-server -- npx -y @cyanheads/wikipedia-mcp-server

For other clients, add this to the MCP config file:

{
  "mcpServers": {
    "wikipedia-mcp-server": {
      "command": "npx",
      "args": ["-y", "@cyanheads/wikipedia-mcp-server"]
    }
  }
}

No API key is required — Wikipedia's API is public. For Docker or a source build, see Running the server.

Configuration

VariableDescriptionDefault
WIKIPEDIA_USER_AGENTUser-Agent header sent with every Wikimedia API request. Customize for your deployment.wikipedia-mcp-server/0.3.0 (https://github.com/cyanheads/wikipedia-mcp-server)
WIKIPEDIA_BASE_URLOptional single-instance override. Unset (default): compose per-language hosts, language selects the edition per call. Set to a full base URL (e.g. a private MediaWiki mirror): route every call at that one fixed host — language no longer varies it.(unset)
WIKIPEDIA_ARTICLE_OVERFLOW_BYTESByte budget above which a full-article read (wikipedia_get_article without section_index) returns a section outline instead of the full text. Tuned for this domain — ordinary articles stay whole; only genuine mega-articles (World War II ~86 KB, United States ~94 KB) outline. Section-targeted reads are never affected.80000
MCP_TRANSPORT_TYPETransport: stdio or http.stdio
MCP_HTTP_PORTPort for HTTP server.3010
MCP_SESSION_MODEHTTP session mode: stateless, stateful, or auto (which resolves to stateful). The Docker image ships stateless.auto
MCP_AUTH_MODEAuth mode: none, jwt, or oauth.none
MCP_LOG_LEVELLog level (RFC 5424).info
LOGS_DIRDirectory for log files (Node.js only).<project-root>/logs
LOG_TOOL_FAILURE_PAYLOADSLog each failed tool call's arguments and result, redacted by key name and capped at LOG_TOOL_FAILURE_PAYLOAD_MAX_BYTES (default 16384). A secret inside a free-form value is not redacted.false
OTEL_ENABLEDEnable OpenTelemetry instrumentation (spans, metrics, completion logs).false

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

Running the server

Local development

Requires Bun v1.4.0 or higher (or Node.js v24+).

  • Clone and install:

    git clone https://github.com/cyanheads/wikipedia-mcp-server.git
    cd wikipedia-mcp-server && bun install
    cp .env.example .env   # optional: customize WIKIPEDIA_USER_AGENT or logging
    
  • Build and run:

    # One-time build
    bun run rebuild
    
    # Run the built server
    bun run start:stdio
    # or
    bun run start:http   # listens at http://localhost:3010/mcp (MCP_HTTP_PORT)
    
  • Run checks and tests:

    bun run devcheck   # Lint, format, typecheck, security
    bun run test       # Vitest test suite
    bun run lint:mcp   # Validate MCP definitions against spec
    

Docker

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

The Dockerfile defaults to HTTP transport, stateless session mode, and logs to /var/log/wikipedia-mcp-server. To run the published image over stdio from an MCP client, use "command": "docker" with "args": ["run", "-i", "--rm", "-e", "MCP_TRANSPORT_TYPE=stdio", "ghcr.io/cyanheads/wikipedia-mcp-server:latest"]. OpenTelemetry peer dependencies are installed by default — build with --build-arg OTEL_ENABLED=false to omit them.

Project structure

DirectoryPurpose
src/index.tscreateApp() entry point — registers tools and inits the Wikipedia service.
src/configServer-specific environment variable parsing and validation with Zod.
src/mcp-server/toolsTool definitions (*.tool.ts) — one file per tool.
src/services/wikipediaWikipediaService — REST API + Action API client with retry/backoff and language validation.
skills/The published wikipedia-guide agent skill, served over MCP and shipped in the package.
tests/Unit and integration tests mirroring src/.

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 request-scoped logging, ctx.state for tenant-scoped storage
  • Register new tools in src/mcp-server/tools/definitions/index.ts
  • 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.