Scholar MCP

Host a copy with our keys and logs.

• SCHOLAR_MCP_KV_STORE_URL — Persistent-state backend URL shared by every pvl-core subsystem that needs state. `memory://` is in-process and lost on restart; `file:///path` persists on one server; `redis://`, `dynamodb://` and `mongodb://` each need their matching extra. When unset, defaults to `file:///data/state` (the volume family Docker images mount), or to `memory://` (with a warning) on a host where that directory is not usable.
• SCHOLAR_MCP_TOOLS_ALLOW — Comma-separated explicit tool names this instance exposes; every other tool is hidden from listings and cannot be invoked. Names matching no registered tool are inert. Mutually exclusive with `tools_deny`. Takes effect through `apply_tool_visibility`.
• SCHOLAR_MCP_TOOLS_DENY — Comma-separated explicit tool names hidden from this instance (absent from listings, cannot be invoked). Names matching no registered tool are inert. Mutually exclusive with `tools_allow`. Takes effect through `apply_tool_visibility`.
• SCHOLAR_MCP_SERVER_NAME — Rename this server instance; defaults to the project name.
• SCHOLAR_MCP_INSTANCE_DESCRIPTION — Concise routing context that distinguishes this deployment's material or responsibility.
• SCHOLAR_MCP_INSTRUCTIONS_EXTRA — Deployment-specific behavioral policy added to the generated MCP instructions.
• SCHOLAR_MCP_INSTRUCTIONS — Legacy: replaces all generated MCP instructions (deprecated; use _INSTANCE_DESCRIPTION for routing and _INSTRUCTIONS_EXTRA for policy).
• SCHOLAR_MCP_LOG_LEVEL — Log level for every logger in the process, FastMCP's included (DEBUG / INFO / WARNING / ERROR / CRITICAL). The -v CLI flag overrides to DEBUG. The unprefixed FASTMCP_LOG_LEVEL still works for one major version and logs a deprecation warning.
• SCHOLAR_MCP_LOG_FORMAT — Log rendering. rich is one colour event key=value line per record, for a terminal; json is one JSON object per record, for a collector. Unset picks rich when stderr is a terminal and json everywhere else, so a container or journald gets JSON with no configuration.
• SCHOLAR_GITHUB_TOKEN — GitHub token used to raise rate limits when fetching standards documents from GitHub. Optional; unauthenticated requests work at reduced limits.
• SCHOLAR_MCP_READ_ONLY — When true, write-tagged tools (PDF download and conversion cache writes) are hidden. Set false to enable them.
• SCHOLAR_MCP_S2_API_KEY — Semantic Scholar API key. Optional but strongly recommended: a key has an introductory 1 req/s allowance; anonymous users share capacity and may be throttled. Request one at https://www.semanticscholar.org/product/api#api-key-form.
• SCHOLAR_MCP_DOCLING_URL — Base URL of a running docling-serve instance for PDF conversion (e.g. http://localhost:5001). When unset, PDF conversion tools return an error.
• SCHOLAR_MCP_VLM_API_URL — OpenAI-compatible VLM endpoint for formula and figure enrichment during PDF conversion.
• SCHOLAR_MCP_VLM_API_KEY — API key for the VLM endpoint.
• SCHOLAR_MCP_VLM_MODEL — Model name to use with the VLM endpoint.
• SCHOLAR_MCP_VLM_PARAMS — JSON object of extra request parameters for every VLM call, overriding the defaults, for a model that needs them (e.g. {"temperature": 1}).
• SCHOLAR_MCP_CACHE_DIR — Directory for the SQLite cache database (cache.db) and downloaded PDFs (pdfs/, md/).
• SCHOLAR_MCP_CONTACT_EMAIL — Contact email for the OpenAlex polite pool (improves rate limits). Also enables Unpaywall lookups as a PDF fallback source.
• SCHOLAR_MCP_EPO_CONSUMER_KEY — EPO Open Patent Services consumer key. Optional; patent tools are hidden when unset. Register at https://developers.epo.org/user/register.
• SCHOLAR_MCP_EPO_CONSUMER_SECRET — EPO Open Patent Services consumer secret. Optional; patent tools are hidden when unset.
• SCHOLAR_MCP_GOOGLE_BOOKS_API_KEY — Google Books API key. Optional; book tools work unauthenticated at reduced rate limits.
• SCHOLAR_MCP_ACCESS_LINKS — Links to a paper through your library, offered when no PDF can be fetched and with each paper lookup: a JSON list of objects with a label and an http(s) URL template, in priority order. Placeholders: {doi}, {doi_url} (the encoded doi.org URL, for wrapping), {openurl} (OpenURL 1.0), {openurl_0_1} and {openurl_hybrid}. Unset means one doi.org link; an empty list turns links off. The server never opens these links. See the PDF conversion guide for examples.
• SCHOLAR_MCP_PDF_FETCH_ALLOW_PRIVATE — When false (the default), a PDF download is refused if the host, or a redirect target, resolves to a loopback, private, link-local or other non-public address. This covers URLs the caller supplies and URLs taken from paper metadata. Set true to allow hosts on the server's own network, such as an intranet repository.
• SCHOLAR_MCP_JOBS_SOFT_DEADLINE_S — Seconds a long-running tool call may run in the foreground before it is promoted to a background job and a job handle is returned instead.
• SCHOLAR_MCP_JOBS_RESULT_TTL_S — Seconds a background-job record (working or finished) is retained for polling before it expires from the store.
• SCHOLAR_MCP_JOBS_MAX_PER_SUBJECT — Maximum live background jobs per calling subject; further promotions are rejected until older records expire.
• SCHOLAR_MCP_TRANSFER_TTL_DEFAULT_S — Link lifetime in seconds when the caller requests no explicit TTL.
• SCHOLAR_MCP_TRANSFER_TTL_MAX_S — Ceiling in seconds a caller-requested link TTL is clamped to.
• SCHOLAR_MCP_TRANSFER_GRACE_TTL_S — Post-success grace window in seconds: a served token's TTL shrinks to this so a stalled transfer can retry within it.
• SCHOLAR_MCP_TRANSFER_LEASE_S — Crashed-handler reclaim window in seconds for an in-flight reservation.
• SCHOLAR_MCP_TRANSFER_MAX_UPLOAD_BYTES — Maximum size in bytes of a single upload.