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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
| Tool | Description |
|---|---|
wikipedia_search_articles | Full-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_summary | Short summary for any article — plain text, Wikidata QID, description, thumbnail URL, page type, canonical URL, revision, and coordinates. |
wikipedia_get_article | Full 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_sections | Table of contents with section_index values for targeted section reads. |
wikipedia_search_nearby | Geotagged Wikipedia articles within a radius of a WGS 84 coordinate, sorted by distance, with short descriptions and Wikidata QIDs. |
wikipedia_get_languages | All language editions available for an article, with titles and URLs, or just the editions you ask for. |
wikipedia_get_references | The 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 withempty_query), positive integerlimit(default 10, clamped to 50), andoffsetpaging, passing back enrichmentnextOffset. Only a clamped call carriesrequestedLimit,appliedLimit, and a clamp notice. Wikipedia serves no result past the 10,000th: anoffsetat or beyond it fails withoffset_too_large, and a page ending on that window carries enrichmenttruncated - CirrusSearch operators include
incategory:"1648 treaties",morelike:Peace of Westphalia,intitle:Python,hastemplate:Infobox, andinsource:Python(support depends on the installation).sortdefaults torelevance; alternatives arelast_edit_desc,create_timestamp_desc,incoming_links_desc, andtitle_natural_asc. Enrichment echoessort; keep it andqueryunchanged when paging - Each result carries a plain-text snippet, page ID, word count, and — when the article has them — its short
descriptionand Wikidata QID (wikibase_item); enrichmentsuggestioncarries Wikipedia's spelling correction (einstien→einstein) - Invalid or over-complex
insource:/…/andintitle:/…/regexes fail once withinvalid_query, theupstreamCode, 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_articlewithsection_index: 0reads the whole lead) — plus the short description, thumbnail URL, Wikidata QID (wikibase_item), and, for a geotagged article,latitude/longitudeto pass straight towikipedia_search_nearby page_typediscriminatesstandard/disambiguation/no-extract(ondisambiguation, re-query withwikipedia_search_articles);url,revision_id, andlast_modifiedname 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 trysection_index: 0. Namespace pages may contain documentation rather than article prose. An empty description is absent; a missing title still fails withnot_found
wikipedia_get_article tool
- Without
section_index: the full article with== Section ==markers, or a section outline (truncated: true) when it exceedsWIKIPEDIA_ARTICLE_OVERFLOW_BYTES(default 80,000 bytes). With asection_indexfromwikipedia_get_sections(0is the lead): that section plus its nested subsections - Outline entries include verified
section_indexvalues 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_fromand, for a section target,redirect_section. A full read remains full and includes targeted-read guidance; an explicitsection_index, including 0, takes precedence - Every read returns
urlandrevision_id(?oldid=<revision_id>is a permanent link to the text read); a full read, outline included, also returnslast_modified. WithWIKIPEDIA_BASE_URLset, a section read omitsurl - 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 notable_index - Section reads also carry data tables as pipe-delimited rows and infoboxes as
label: valuelines, which the full-article extract strips; a table over 40,000 rendered bytes leaves a[table omitted: N rows (table T)]marker. Passtable_index: Twith the section to read that table in complete row pages, then follownext_cursorascursorwith 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 withoversized_row: true
wikipedia_get_sections tool
- Takes a
title; returns section titles, heading levels, hierarchical numbering (e.g."2.1"), and thesection_indexto pass towikipedia_get_article— the first entry is the lead (index: 0, titledIntroduction) - Heading titles use the article renderer’s script, formula, whitespace and single-pass entity normalization, so
CO₂stays identical across the section list, article reads and verified outline entries - Fails with
no_sectionson a stub or very short article — read it withwikipedia_get_articleinstead - Redirect aliases expose
redirected_fromand optionalredirect_section;redirect_section_indexappears only when a unique anchor matches a real numeric TOC index
wikipedia_search_nearby tool
latitude−90…90 /longitude−180…180 (WGS 84),radius_meters10–10,000 (default 1000), and positive integerlimit(default 10, clamped to 500), with no pagination pastlimit; enrichmenttruncatedflags more matches thanlimitallowed — at 500, Wikipedia's ceiling, sweep narrower radii instead. Only a clamped call carriesrequestedLimit,appliedLimit, and a clamp notice- Returns articles sorted by
distance_meters, with coordinates, shortdescription, 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'slanguage_code,edition_code, article title, and URL, plussource_title, the resolved title. Passedition_code— notlanguage_code— aslanguageon other tools; the two can differ (gswvsals) editionsnarrows the list to the codes asked for: codes with no article come back undermissing, andtotal_languagesstays the unfiltered count. Fails withno_other_languageswhen the article has no translations; a filter matching nothing is an empty list, not a failure
wikipedia_get_references tool
- Takes a
title; returnsreferences[]in document order across every reference list, each withid,label(the in-text marker),group(a notes list such aslower-alpha, absent for the main list),text,urls(archive copies included), anddois(fromdoi.orglinks, percent-decoded).total_referencescounts the footnotes on all pages.wikipedia_get_articledrops footnote markers and reference lists - A short citation such as "Galinsky 2012, pp. 75–76" carries
work_ids, andworkson 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 withwikipedia_get_article - Each page holds whole footnotes within 40,000 UTF-8 bytes on both surfaces; follow
next_cursorascursorwith the sametitleandlanguage. Continuations read the first page'srevision_id, and a cursor past the last footnote failsinvalid_cursor. An unreadable pinned revision failsrevision_unavailable. An article with no footnotes returns an empty list with anotice, 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-Afterhonored and each request's retries bounded at 30 s. The best-effort description lookup on search results gets one short attempt;User-Agentheader 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 RESTextract_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_referencesreturns the footnotes - Per-call
languageparameter on every tool (defaulten) — 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=sitematrixendpoint (cached 24h) — catches structurally valid but nonexistent editions before they cause timeouts
Agent-friendly output:
page_typeon summaries discriminatesstandard/disambiguation/no-extract— no string parsing neededwikibase_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;structuredContentcarries the same text unescaped. Fenced code blocks and table-row delimiters pass through unescaped, while table cells stay escaped section_indexon table-of-contents entries links directly to the targeted-read parameter onwikipedia_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, withinvalid_title; a trailing#fragmentis accepted and resolves normally - Recovery hints on every error type — callers get actionable next steps (e.g., "use
wikipedia_search_articlesto 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
| Variable | Description | Default |
|---|---|---|
WIKIPEDIA_USER_AGENT | User-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_URL | Optional 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_BYTES | Byte 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_TYPE | Transport: stdio or http. | stdio |
MCP_HTTP_PORT | Port for HTTP server. | 3010 |
MCP_SESSION_MODE | HTTP session mode: stateless, stateful, or auto (which resolves to stateful). The Docker image ships stateless. | auto |
MCP_AUTH_MODE | Auth mode: none, jwt, or oauth. | none |
MCP_LOG_LEVEL | Log level (RFC 5424). | info |
LOGS_DIR | Directory for log files (Node.js only). | <project-root>/logs |
LOG_TOOL_FAILURE_PAYLOADS | Log 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_ENABLED | Enable 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
| Directory | Purpose |
|---|---|
src/index.ts | createApp() entry point — registers tools and inits the Wikipedia service. |
src/config | Server-specific environment variable parsing and validation with Zod. |
src/mcp-server/tools | Tool definitions (*.tool.ts) — one file per tool. |
src/services/wikipedia | WikipediaService — 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/catchin tool logic - Use
ctx.logfor request-scoped logging,ctx.statefor 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.