ScholarMCP reads configuration from environment variables (and automatically loads .env in the current working directory at startup).
Boolean values accept true/false, 1/0, yes/no, and on/off.
Core Runtime
| Variable | Default | Description |
|---|---|---|
NODE_ENV | development | Runtime environment (development, test, production). |
LOG_LEVEL | info | Log verbosity (debug, info, warn, error). |
SCHOLAR_MCP_SERVER_NAME | scholar-mcp | MCP server identity name. |
SCHOLAR_MCP_SERVER_VERSION | package version | MCP server version reported to clients. |
SCHOLAR_MCP_TRANSPORT | stdio | Transport mode: stdio, http, or both. |
HTTP Server
| Variable | Default | Description |
|---|---|---|
SCHOLAR_MCP_HOST | 127.0.0.1 | HTTP bind host. |
SCHOLAR_MCP_PORT | 3000 | HTTP bind port. |
SCHOLAR_MCP_ENDPOINT_PATH | /mcp | MCP HTTP endpoint path. |
SCHOLAR_MCP_HEALTH_PATH | /health | Health check endpoint path. |
SCHOLAR_MCP_HTTP_SESSION_MODE | stateful | HTTP session mode: stateful or stateless. |
SCHOLAR_MCP_HTTP_SESSION_TTL_MS | 1800000 | Stateful session time-to-live in milliseconds. |
SCHOLAR_MCP_HTTP_MAX_SESSIONS | 200 | Maximum concurrent HTTP sessions. |
Security and Access Control
| Variable | Default | Description |
|---|---|---|
SCHOLAR_MCP_API_KEY | unset | If set, requires Authorization: Bearer <key> for HTTP requests. |
SCHOLAR_MCP_ALLOWED_ORIGINS | unset | Comma-separated CORS allow-list for origins. |
SCHOLAR_MCP_ALLOWED_HOSTS | unset | Comma-separated host header allow-list. |
Google Scholar Tuning
| Variable | Default | Description |
|---|---|---|
SCHOLAR_BASE_URL | https://scholar.google.com | Scholar base URL. |
SCHOLAR_LANGUAGE | en | Scholar language code used by search calls. |
SCHOLAR_TIMEOUT_MS | 15000 | Request timeout for Scholar calls. |
SCHOLAR_RETRY_ATTEMPTS | 2 | Retry count for Scholar requests. |
SCHOLAR_RETRY_DELAY_MS | 800 | Base retry delay for Scholar requests. |
SCHOLAR_REQUEST_DELAY_MS | 250 | Inter-request pacing delay for Scholar traffic. |
SCHOLAR_MAX_RESULTS_PER_REQUEST | 20 | Maximum results fetched per Scholar request. |
Federated Research Providers
| Variable | Default | Description |
|---|---|---|
RESEARCH_OPENALEX_BASE_URL | https://api.openalex.org | OpenAlex API base URL. |
RESEARCH_OPENALEX_API_KEY | unset | Optional OpenAlex API key. |
RESEARCH_CROSSREF_BASE_URL | https://api.crossref.org | Crossref API base URL. |
RESEARCH_SEMANTIC_SCHOLAR_BASE_URL | https://api.semanticscholar.org/graph/v1 | Semantic Scholar API base URL. |
RESEARCH_SEMANTIC_SCHOLAR_API_KEY | unset | Optional Semantic Scholar API key. |
RESEARCH_TIMEOUT_MS | 20000 | Timeout for federated research HTTP requests. |
RESEARCH_RETRY_ATTEMPTS | 2 | Retry count for federated requests. |
RESEARCH_RETRY_DELAY_MS | 800 | Base retry delay for federated requests. |
RESEARCH_REQUEST_DELAY_MS | 100 | Inter-request pacing for federated providers. |
Full-Text Ingestion
| Variable | Default | Description |
|---|---|---|
RESEARCH_ALLOW_REMOTE_PDFS | true | Allows remote PDF download ingestion. |
RESEARCH_ALLOW_LOCAL_PDFS | true | Allows local PDF path ingestion. |
RESEARCH_GROBID_URL | unset | Optional GROBID endpoint URL. |
Extraction and Graph Ranking
| Variable | Default | Description |
|---|---|---|
RESEARCH_SEMANTIC_ENGINE | cloud-llm | Extraction engine mode (cloud-llm or none). |
RESEARCH_CLOUD_MODEL | gpt-4.1-mini | Model name used by cloud extraction engine. |
RESEARCH_GRAPH_CACHE_TTL_MS | 300000 | Literature graph cache TTL in milliseconds. |
RESEARCH_GRAPH_MAX_CACHE_ENTRIES | 300 | Maximum cached graph entries. |
RESEARCH_GRAPH_PROVIDER_RESULT_MULTIPLIER | 2 | Per-provider over-fetch multiplier before merge/ranking. |
RESEARCH_GRAPH_FUZZY_TITLE_THRESHOLD | 0.84 | Fuzzy title dedupe threshold for merged works. |