Access the OpenAlex academic research catalog - 270M+ publications through MCP. STDIO & Streamable HTTP.
Install
npx -y @cyanheads/openalex-mcp-serverOPENALEX_API_KEYoptional — OpenAlex account API key, sent as api_key= - optional (free from https://openalex.org/settings/api). Without it, anonymous rate limits apply.OPENALEX_MAILTOoptional — Optional email sent as mailto= to identify yourself to OpenAlex (the polite pool). Separate from the API key.OPENALEX_BASE_URLoptional — OpenAlex API base URL.MCP_LOG_LEVELoptional — Sets the minimum log level for output (e.g., 'debug', 'info', 'warn').
@cyanheads/openalex-mcp-server
Access the OpenAlex academic research catalog - 270M+ publications through MCP. STDIO & Streamable HTTP.
Public Hosted Server: https://openalex.caseyjhand.com/mcp
Overview
Scholarly catalog data from OpenAlex — 270M+ works, 90M+ authors, 100K+ sources, plus institutions, topics, keywords, publishers, and funders. Search, filter, and aggregate across all eight entity types, resolve ambiguous names to canonical IDs, and walk the citation graph one hop at a time. Runs as a stdio process, a local Streamable HTTP server, or the public hosted endpoint above.
Tools
| Tool | Description |
|---|---|
openalex_search_entities |
Search, filter, sort, or retrieve by ID across all 8 entity types |
openalex_analyze_trends |
Group-by aggregation for trend and distribution analysis |
openalex_resolve_name |
Resolve a name or an identifier (DOI, ORCID, ROR, PMID, ISSN, OpenAlex ID) to an OpenAlex ID |
openalex_get_citation_graph |
Walk the citation graph one hop from a seed work: cites, cited_by, or related_to |
openalex_describe_fields |
List valid filter, group_by, and select field names for an entity type |
Prompts
| Prompt | Description |
|---|---|
openalex_literature_review |
Guides a systematic literature search: formulate query, search, filter, analyze citation network, synthesize findings |
openalex_research_landscape |
Analyzes the research landscape for a topic: volume trends, top authors/institutions, open access rates, funding sources |
Capability reference
openalex_search_entities tool
- Retrieve a single entity by ID — OpenAlex ID, DOI, ORCID, ROR, PMID, ISSN, or PMCID (bare or URL form), or a keyword by its slug or keyword URL.
idtakes precedence: search parameters passed alongside it are dropped, and the response names which ones. A PMCID resolves nothing (OpenAlex indexes none) — use the work's PMID or DOI instead - Keyword search (boolean operators, quoted phrases, wildcards, fuzzy match) plus
exactandsemanticsearch modes — semantic ranks a query-dependent candidate set at ~1 req/sec (up to 50 per page), and itsmeta.countreports the candidate count rather than a match total - Rich filter syntax: AND across fields, OR within a field (
|), NOT (!), ranges, comparisons; a comma inside a filter value is rejected (use|, or a.searchfilter for free text) selectreturns a curated per-entity-type default unless overridden, or["*"]for the full record; invalid field names error with the valid set- Cursor pagination for keyword and exact search, up to 100 results per page (default 25); semantic search walks its candidates with
page(1-based) instead, and mixing either knob with the wrongsearch_modeis rejected before the upstream call sample(up to 100, single page only — neithercursornorpageapplies) plus a deterministicseedfor reproducible random sampling; keyword and exact modes only, and never alongsidesort— OpenAlex does not sample a semantic search and refuses a sorted sample, so both combinations are rejected before the upstream call- Each response holds to 64,000 bytes per surface (
structuredContent, andcontent[]with its trailer) unless the least it can return is larger, which it flags asover_budget: a page that would run over keeps its leading records whole and names the rest inomittedwith the one call that returns them (as a set, in OpenAlex's order), without disturbingnext_cursor; a record too large on its own comes back with its largest arrays windowed, filled in turn so each shows what fits and labeled with how much of the array it holds, andslice: {field, offset}on anidlookup pages any array to the end - A list record carrying exactly 100
authorships— the most OpenAlex returns in a list response — is flagged as possibly capped, with the unbilledid+slicecall that fetches the rest display_nameis nullable for untitled records; every call reports OpenAlex daily-budget cost and remaining balance
openalex_analyze_trends tool
- Group any supported field for trend, distribution, or comparative analysis; combine with
filtersto scope the population before aggregation - Up to 200 groups per page (default).
order: "count"(default) returns the top-N by count with no further pages;order: "key"enumerates all distinct values key-ascending with cursor pagination include_unknown(defaultfalse) adds a group for entities with no value for the grouped field, flaggedis_unknown: trueand labeled as unknown in the text output. OpenAlex keys it-111/-111.0(numeric fields),unknown(text fields andorder: "key"), or an ID ending in/unknown; the key is a sentinel, not a filter value. Boolean fields have no such group — a missing value counts asfalse- Not every field is groupable — raw date fields,
.searchoperators,from_*/to_*range modifiers, decimal scores such asfwci,display_name, and external-ID fields such asdoiare rejected;openalex_describe_fields(entity_type, "group_by")lists the fields that group - A works group_by on
authorships.countriessays in its notice that OpenAlex counts only each work's first 100 authorships for that field, and namesauthorships.institutions.country_codeas the field that counts all of them - Reports OpenAlex daily-budget cost and remaining balance — aggregation is priced far below paging the same entities
openalex_resolve_name tool
- A name or partial name runs an autocomplete search: up to 10 matches with disambiguation hints (last institution, host organization, place, etc.)
- An identifier — OpenAlex ID, DOI, ORCID, ROR, PMID, ISSN, or keyword URL, bare or in URL form — resolves directly to the one record it addresses; no
entity_typeneeded, since the identifier determines its own. A PMCID is recognized but resolves nothing — OpenAlex indexes none filtersnarrows autocomplete only; on an identifier lookup they're ignored and named in a notice- With
entity_typeset, OpenAlex autocomplete fails on a name over 1,000 characters; that failure is reported once asquery_too_longwith advice to shorten the name, not retried as an outage - Reports OpenAlex daily-budget cost and remaining balance
openalex_get_citation_graph tool
directionsets the edge:cites(works citing the seed),cited_by(the seed's own reference list),related_to(OpenAlex's algorithmic related works, ~8-30 typical, may be empty)seed_idaccepts an OpenAlex ID, DOI, or PMID (PMCID recognized but resolves nothing); validated against a live lookup first, so a non-existent seed fails asNotFoundrather than returning an empty graph- Stacks with
filters/sort/selectto narrow the graph;filterscannot setcites/cited_by/related_to, nor an alias of one such ascited_works— those keys are reserved fordirection - Cursor pagination, up to 100 results per page (default 25)
- The same 64,000-byte response budget and 100-authorship cap disclosure as
openalex_search_entities; works cut from a page are named inomittedwith theopenalex_search_entitiescall that returns them, in OpenAlex's order - Reports OpenAlex daily-budget cost, covering both the seed-validation lookup and the graph page, plus remaining balance
openalex_describe_fields tool
- Lists every valid field name for an entity type + context (
filter,group_by,select) — the complete pool, never truncated group_byis the filter set minus what OpenAlex rejects as an aggregation key: raw date fields,.search/.search.exactoperators,from_*/to_*range modifiers, and a per-entity-type set found by grouping every listed field against the live API — decimal scores such asfwci, several source year fields,display_name, and external-ID fields among them- Optional
queryreorders results by name similarity without dropping any field — a nested value's parent object stays reachable further down the list - Backed by a generated field catalog — no live API calls
openalex_literature_review prompt
- Arguments:
topicrequired;scope(narrow/broad) optional, defaults tonarrow - Returns one user message walking a 6-step workflow: resolve entities, search literature, identify key papers, trace citations, analyze the landscape, synthesize findings
scopechanges the search step:narrowfavors exact search with tight topic filters;broadadds semantic search across multiple related topic IDs
openalex_research_landscape prompt
- Arguments:
topicrequired - Returns one user message walking a 7-step quantitative workflow: resolve the topic ID, volume trends, top contributors (institutions/countries/journals), open access rate, funding sources, most-cited works, emerging fronts
- The funding step groups by
awards.funder_id(resolve names viaopenalex_resolve_name) orawards.funder_display_namefor readable labels in a single hop
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.
OpenAlex-specific:
- Typed API client with automatic ID normalization (DOI, ORCID, ROR, PMID, PMCID, ISSN, OpenAlex and PubMed/PubMed Central URLs); a PMCID normalizes but resolves nothing since OpenAlex indexes none
- Keyless by default — an optional API key raises rate and daily-budget limits, and an optional
mailtoidentifies the caller to OpenAlex's polite pool - HTTP status codes mapped to specific MCP error classes (400 → InvalidParams, 422 → ValidationError, 429 → RateLimited) with upstream messages surfaced
- Timeout-aware request retries and cancellation support via
AbortSignal
Agent-friendly output:
- Provenance — every API-calling tool reports OpenAlex daily-budget cost, remaining balance, and reset time (
budget.costUsd,remainingUsd,resetsInSeconds) - Effective-query echo — search, trends, and citation-graph responses echo the criteria that actually ran, so an empty result is diagnosable without re-reading the request
- Discriminated output contracts — typed error reasons (
entity_not_found,upstream_budget_exhausted,semantic_per_page_cap,reserved_filter_key, and more) each carrying an explicit recovery hint - Response shaping — abstracts are reconstructed from OpenAlex's inverted-index encoding into plaintext, and
display_namestaysnullfor untitled or paratext records instead of being backfilled - Clean provider text — OpenAlex passes titles, abstracts, and names through unsanitized; HTML entities are decoded against the full WHATWG table, comments and HTML/JATS/MathML formatting tags are removed, CDATA wrappers and IOP's
<?CDATA …?>math markers are unwrapped with their TeX kept, and a double-escaped line break (a literal\n) becomes a space; literal text such asA < Band TeX such as\nuis kept. Identifier and URL fields (id,doi,ids,orcid,ror,issn,*_url, lineages) are returned exactly as OpenAlex stores them, so each one resolves when passed back. The text output escapes that text for Markdown, so a stray*,<tag>, or[x](y)renders as written; IDs, and URLs that render as links, stay byte-identical
Getting started
Public Hosted Instance
A public instance is available at https://openalex.caseyjhand.com/mcp — no installation required. Point any MCP client at it via Streamable HTTP:
{
"mcpServers": {
"openalex-mcp-server": {
"type": "streamable-http",
"url": "https://openalex.caseyjhand.com/mcp"
}
}
}
Self-Hosted / Local
Add the following to your MCP client configuration file.
{
"mcpServers": {
"openalex-mcp-server": {
"type": "stdio",
"command": "bunx",
"args": ["@cyanheads/openalex-mcp-server@latest"],
"env": {
"MCP_TRANSPORT_TYPE": "stdio",
"MCP_LOG_LEVEL": "info",
"OPENALEX_API_KEY": "your-api-key"
}
}
}
}
Or with npx (no Bun required):
{
"mcpServers": {
"openalex-mcp-server": {
"type": "stdio",
"command": "npx",
"args": ["-y", "@cyanheads/openalex-mcp-server@latest"],
"env": {
"MCP_TRANSPORT_TYPE": "stdio",
"MCP_LOG_LEVEL": "info",
"OPENALEX_API_KEY": "your-api-key"
}
}
}
}
Or with Docker:
{
"mcpServers": {
"openalex-mcp-server": {
"type": "stdio",
"command": "docker",
"args": [
"run", "-i", "--rm",
"-e", "MCP_TRANSPORT_TYPE=stdio",
"-e", "OPENALEX_API_KEY=your-api-key",
"ghcr.io/cyanheads/openalex-mcp-server:latest"
]
}
}
}
For Streamable HTTP, set the transport and start the server:
MCP_TRANSPORT_TYPE=http MCP_HTTP_PORT=3010 OPENALEX_API_KEY=... bun run start:http
# Server listens at http://localhost:3010/mcp
OPENALEX_API_KEY is optional — set it to a free OpenAlex account key for keyed rate limits and budget under OpenAlex's usage-based pricing, or omit it for anonymous access. Set OPENALEX_MAILTO to an email if you want to identify yourself to OpenAlex (the polite pool).
Prerequisites
- Bun v1.4.0 or higher (or Node.js v24+).
- Optional: an OpenAlex account API key for keyed rate limits and budget — omit for anonymous access.
Installation
- Clone the repository:
git clone https://github.com/cyanheads/openalex-mcp-server.git
- Navigate into the directory:
cd openalex-mcp-server
- Install dependencies:
bun install
- Configure environment:
cp .env.example .env
# edit .env and set required vars
Configuration
| Variable | Description | Default |
|---|---|---|
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 (resolves to stateful). The server declares stateless in code; an explicit value overrides it. |
stateless |
MCP_AUTH_MODE |
Auth mode: none, jwt, or oauth. |
none |
MCP_ALLOWED_ORIGINS |
Comma-separated allow-list of browser Origin headers for HTTP transport. Unset = loopback-only; set to * to disable. |
loopback only |
MCP_LOG_LEVEL |
Log level (RFC 5424). | debug |
LOGS_DIR |
Directory for log files (Node.js only). | <project-root>/logs |
STORAGE_PROVIDER_TYPE |
Storage backend. | in-memory |
OPENALEX_API_KEY |
OpenAlex account API key, sent upstream as api_key= (free from openalex.org/settings/api). Without it, anonymous rate limits apply. |
— |
OPENALEX_MAILTO |
Email sent upstream as mailto= to identify yourself to OpenAlex (the "polite pool"); a courtesy identifier, separate from the API key. |
— |
OPENALEX_BASE_URL |
OpenAlex API base URL. | https://api.openalex.org |
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
Build and run:
# One-time build bun run rebuild # Run the built server bun run start:stdio # or bun run start:httpRun checks and tests:
bun run devcheck # Lints, formats, type-checks bun run test # Runs the test suite
Docker
docker build -t openalex-mcp-server .
docker run --rm -e OPENALEX_API_KEY=your-key -p 3010:3010 openalex-mcp-server
The Dockerfile defaults to HTTP transport, stateless session mode, and logs to /var/log/openalex-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 prompts. |
src/config/ |
Server-specific environment variable parsing and validation with Zod. |
src/mcp-server/tools/definitions/ |
Tool definitions (*.tool.ts). |
src/mcp-server/prompts/definitions/ |
Prompt definitions (*.prompt.ts). |
src/services/openalex/ |
OpenAlex API client, field catalog, and domain types. |
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/catchin tool logic - Use
ctx.logfor logging,ctx.statefor storage - Wrap OpenAlex responses: validate the raw payload → normalize to a domain type → return the output schema; never fabricate missing fields
- Always resolve names to IDs via
openalex_resolve_namebefore filtering by entity
Contributing
Issues are welcome. Run checks before submitting:
bun run devcheck
bun run test
License
Apache-2.0 — see LICENSE for details.
