Brain Server is configured entirely through environment variables , all resolved in src/config.rs. There is no config file to edit. This page is the complete reference, grouped by concern.
Variable Default Description
BIND_HOST127.0.0.1Bind address. 0.0.0.0 refused unless BIND_PUBLIC=1. BIND_PORT8765Listen port BRAIN_DB_PATH~/.openclaw/workspace/brain.dbSQLite database path BRAIN_DATA_ROOT— v1.0 relocation knob — root for all on-disk paths BRAIN_WORKER_THREADS# cores Tokio runtime worker threads (set 2 on Jetson) CORS_ORIGINShttp://localhost:3000,http://localhost:8080CORS allowlist BRAIN_CLIENT_DIRclient/distDirectory served at /app (the web GUI) BRAIN_CHAIN_CHECK_SECS60How often the background audit-chain integrity check runs BRAIN_MULTI_DB— Enables per-domain SQLite files (multi-DB mode) BRAIN_CONTROLLER_NAME— Operator/controller identity label MODEL_PROFILE— Model profile selector (affects embedding defaults) DOMAIN_MIN_COUNT— Minimum chunk count for a domain to be listed/used
Variable Default Description
AUTH_TOKEN / AUTH_TOKEN_FILE— Opaque bearer token(s). Newline-separated = live rotation. Off if unset. BRAIN_JWT_ISSUER— Enables JWT mode when set + keys loaded. URL of the issuer (verified against the iss claim). BRAIN_JWT_KEY_DIR~/.config/brain-server/keys/Directory holding JWT signing key PEMs (mode 0700; private keys 0600). BRAIN_JWT_AUDIENCEbrain-serverExpected aud claim value. BRAIN_PUBLIC_BASE_URL— Public base URL for OIDC discovery. Never inferred from Host. BRAIN_UMP_KEY_DIR~/.config/brain-server/ump/Directory holding the UMP operator Ed25519 signing key (distinct from the JWT key dir). BRAIN_TRUST_PROXYoff When set, trust X-Forwarded-For from the named proxy for real-IP + rate-limit accounting. Off by default so a spoofed header can’t bypass rate limits.
Variable Default Description
PRF_ENABLEDtruePRF query expansion on/off PRF_DEPTH10PRF expansion depth PRF_TERMS5Number of expansion terms PRF_MAX_RANK5Max rank for expansion candidates BRAIN_RECALL_ROUTING_ENABLEDtrueAutomatic retrieval routing (v1.13.1). false restores legacy shim behavior. BRAIN_GRAPH_RESCUE_ENABLEDtrueComplexity-gated graph rescue pass on abstention (v1.12)
PII control is deterministic read-time output redaction (always-on for
principals without pii:read/Admin); there is no write-time placeholder vault
and no BRAIN_REDACT_PII knob (removed v1.20.19).
Variable Default Description
INJECTION_POLICYquarantinequarantine | reject | allow — how prompt-injection-suspicious input is handled.BRAIN_INGEST_SKIP_PATTERNS— (off) Newline- or comma-separated prefixes; text beginning with any is skipped at ingest (e.g. `!redacted,```). Opt-in; default behavior unchanged. BRAIN_INJECTION_CLASSIFIER— Injection classifier selector BRAIN_INJECTION_TOKENIZER— Tokenizer used by the injection classifier BRAIN_INJECTION_THRESHOLD_HIGH— Classifier banding: score ≥ this → reject BRAIN_INJECTION_THRESHOLD_LOW— Classifier banding: score ≥ this (below high) → quarantine BRAIN_PROPOSAL_TTL_SECS604800 (7 d)How long a proposal can sit pending before auto-expire (audited). BRAIN_DSAR_WINDOW_DAYS30GDPR Art 17 response window shown on DSARs BRAIN_DSAR_LEDGER_DAYS30Retention window for the DSAR ledger BRAIN_RETENTION_ENABLED— Enable per-kind query-time retention expiry BRAIN_RETENTION_KIND_DAYS— Per-kind retention overrides (kind=days,kind=days) BRAIN_ALERT_WEBHOOK_URL / BRAIN_ALERT_WEBHOOK_SECRET— Outbound alert webhook sink (uses the hardened egress client)
Variable Default Description
BRAIN_AUDIT_READ_EVENTSon (JWT) / off (loopback)When on, /recall, /search, /get/{id}, /multi-get emit hash-chained audit rows (no content, no raw query). BRAIN_AUDIT_READ_SAMPLE_RATE1.0Read-event sampling (0.0..=1.0); 1.0 = every read event. BRAIN_AUDIT_RETENTION_DAYSunset = forever Audit retention window; when set, expired rows are pruned and the chain re-anchored. Deployers subject to AI Act Art 26(6) guidance: set ≥180. BRAIN_DSAR_WEBHOOK_URL / BRAIN_DSAR_WEBHOOK_SECRET— Opt-in Art 19 onward-notification: on a completed DSAR purge, POSTs {subject, certified_at, certificate_id} HMAC-SHA256-signed. Fail-soft. BRAIN_OTEL_ENABLED / BRAIN_OTEL_ENDPOINToff Optional OpenTelemetry export (endpoint + on/off) CORS_METHODSGET,POST,PUT,DELETE,OPTIONSAllowed CORS methods CORS_HEADERScontent-type,authorizationAllowed CORS request headers
Variable Default Description
BRAIN_SUGGEST_ENABLEDtruev1.9 kill switch: when false, the /suggest/* routes return 501.
Variable Default Description
CAPACITY_MAX_DOCS / CAPACITY_MAX_DB_MIB / CAPACITY_MAX_RSS_MIBcapacity profile Tighten the /health capacity envelope. Writes over the envelope return HTTP 507; reads are never blocked.
The single source of truth for every tunable is src/config.rs in the repository.