Skip to main content
There are two configuration surfaces: the Guard constructor (per-agent, code-level) and environment variables (server-level).

​
Guard constructor

Guard(
    policy=Policy.DEFAULT,        # "default" | "hipaa" | "sox" | "legal_privilege" | Policy enum
    permissions=None,             # list[str]; default: ["*"] (no capability restriction)
    budget_cents=10_000,          # int; per-guard spending ceiling
    on_violation=None,            # Callable[[VerifyResult], None]
    auto_redact=True,             # bool; auto-redact PII when policy redacts
    agent_id="default-agent",     # str; appears in audit log entries
)
The signature lives at certior/guard.py:167. The Guard.verify(...) and Guard.wrap(...) methods then take per-call required_capabilities and cost_cents.

​
Verification stack

Three formal tools, three jobs - all driven by the same Guard configuration:
ToolWhen it runsConfigured by
Z3 (SMT)Every verify(...) call (~tens of ms).Built into the runtime. No separate env var.
Lean 4Offline / CI on every commit. Optional live flow checker when the binary is configured.CERTIOR_FLOW_CHECK_BINARY for the live path. See Lean binary.
DafnyOffline / CI.Built into the runtime modules and export path. No env var toggle.
When the Lean live binary is not configured, the runtime uses the Python implementation of the same subset/budget rule whose soundness Lean has proven offline.

​
Server environment variables

When running with the FastAPI server (./run.sh), these env vars control behaviour:
VariableDefaultDescription
CERTIOR_HOST127.0.0.1Bind address. Use 0.0.0.0 for Docker / remote access.
CERTIOR_PORT8000HTTP port.
CERTIOR_ENVdevelopmentdevelopment enables auto-reload; production disables it and tightens logging.
CERTIOR_STUDIO_URLhttp://127.0.0.1:3001URL for the Studio Next.js frontend.
CERTIOR_WORKSPACE/tmp/certior-workspaceDirectory for file tool operations. Created on startup.
DATABASE_URL(unset)PostgreSQL DSN. When set, executions and events are persisted to PostgreSQL. Requires the [postgres] extra.
REDIS_URL(unset)Redis DSN. When set, background tasks dispatch via Celery / Redis. Requires the [redis] extra.
CERTIOR_DATA_DIR(unset)Fallback SQLite directory when DATABASE_URL is not set.
OPENAI_API_KEY(unset)Enables the OpenAI agent loop.
ANTHROPIC_API_KEY(unset)Enables the Anthropic agent loop.
CERTIOR_LLM_PROVIDER(auto)Force provider when both keys are set. openai or anthropic.
CERTIOR_MODELper-provider defaultOverride the model name.
CERTIOR_FLOW_CHECK_BINARY(unset)Path to the Lean certior-flow-check binary for live flow verification.
The full reference - including production guidance for PostgreSQL DSNs, secret handling, and the Docker Compose host-env pattern - lives in CONFIGURATION.md.

​
Backend priority

When the server starts, persistence backends are selected in order:
  1. DATABASE_URL set → PostgreSQL state store + event bus.
  2. REDIS_URL set → Celery / Redis task queue (combinable with PostgreSQL or SQLite).
  3. CERTIOR_DATA_DIR set → SQLite single-node persistence.
  4. None set → in-memory (testing only; data lost on restart).

​
See also