Engine environment reference

This is the SASY_* inventory for the core Rust sasy binary and its policy runtime. These are process settings, not policy facts. Explicit CLI values take precedence where a variable has a corresponding flag. A variable for an unavailable backend or build feature does not enable that feature. Use sasy serve --help for flags; see configuration for complete startup examples.

SDK variables such as SASY_URL and SASY_API_KEY, guard variables such as SASY_HOME, and Make variables such as SASY_BIN configure their respective clients or launchers; the core engine does not read them as listener or authentication configuration. The server needs --auth-provider even when a client API key is in its environment.

Authentication and credential sources

Variable	Default	Meaning
SASY_ALLOW_NO_AUTH	off	Explicitly allow startup without an authentication provider for local development. This removes caller authentication; use a configured provider for any shared deployment.
SASY_API_KEY_SUFFIX	unset	Legacy server compatibility: append -<suffix> to every configured static key. Leave unset when provisioning independent full keys. SDKs accept full keys and do not compose suffixes.
SASY_ALLOW_DEFAULT_KEYS	off	Local development override accepting the repository’s known example keys verbatim. Replace example keys instead for shared deployments.
SASY_CREDENTIAL_BACKEND	sqlite	--credential-backend: sqlite, memory, or openbao. The memory backend shares its seeded credentials across tenants.
SASY_CREDENTIALS_ENV_FILE	unset	--credentials-env-file: additional credentials for the memory backend; file entries override the process environment. Other backends warn and ignore this option.
SASY_CREDENTIAL_<SERVICE>_<KEY>	unset	Seed a credential for the memory backend, or from an env file passed to init-credentials. Split at the first underscore after the prefix; service and key become lowercase. These wildcard-entity credentials are available to all authenticated entities in the backend’s scope.

The default-off boolean switches above accept 1, true, yes, or on (case-insensitive, whitespace trimmed). They do not provision credentials. Standard provider variables OPENAI_API_KEY, OPENFDA_API_KEY, and BRAVE_API_KEY also seed the credential sources. OpenBao uses the OPENBAO_* counterparts of its CLI flags; see sasy serve --help.

Evaluation and session lifetime

Variable	Default	Meaning
SASY_QUERY_TIMEOUT_SECS	10	--query-timeout-secs: fail-closed answer deadline. The evaluator can finish its in-flight operation after the request is refused.
SASY_EVALUATOR_STALL_SECS	60	--evaluator-stall-secs: kill and replace an evaluator that owes a reply beyond this interval. Must be at least the query deadline.
SASY_SESSION_IDLE_TTL_SECS	1800	Idle evaluator lifetime; 0 disables idle eviction. Recorded graph state survives eviction.
SASY_SESSION_SWEEP_INTERVAL_SECS	60	Interval between session and policy-orphan sweeps; 0 disables both.
SASY_POLICY_VARIANT_IDLE_TTL_SECS	3600	Idle lifetime of unreferenced policy variants; 0 disables orphan sweeping.
SASY_MAX_LIVE_SESSIONS	unbounded	Positive cap on live per-session evaluators. Evicts the least recently active evaluator when needed; 0 also means unbounded. This is not a durable graph-storage quota.
SASY_REPLAY_EAGER	off	Compile persisted policies eagerly on startup instead of loading them on demand. Accepts the default-off boolean spellings above.
SASY_ORACLE_REDACTION	on	--oracle-redaction: on or off scrubbing of recognized secret shapes in oracle question/context strings. Does not redact the graph or the agent’s own model requests. Unrecognized values leave redaction on.

Compilation and confinement

Variable	Default	Meaning
SASY_COMPILE_TIMEOUT_SECS	300	Timeout for each external compiler/preprocessor step; bounds hung toolchain processes.
SASY_SOUFFLE_ASSETS	embedded assets	Directory containing all six assets emitted by sasy install-assets. Missing assets are refused.
SASY_SOUFFLE_INCLUDE	detected headers	Directory containing souffle/SouffleInterface.h.
SASY_SOUFFLE_BUILD_CACHE_DIR	<data-dir>/souffle-build-cache	Compiled evaluator cache. Empty, off, false, or 0 disables caching. Relative paths use the process working directory.
SASY_SOUFFLE_BUILD_CACHE_MAX_BYTES	1073741824 (1 GiB)	Positive cache byte budget. Zero or invalid values use the default.
SASY_SOUFFLE_BUILD_CACHE_MAX_AGE_DAYS	30	Prune unused cache entries by age; 0 disables age pruning while preserving the byte budget.
SASY_SOUFFLE_BUILD_CACHE_PER_TENANT	off	Experimental tenant cache-key switch. The current runtime compilation path does not supply a tenant key, so enabling this emits a warning and leaves the cache shared. Do not rely on it for tenant isolation.
SASY_SOUFFLE_MAGIC_SET	unset	Nonempty relation selection forwarded to Soufflé’s magic-set option. Changes compiled cache identity; leave unset unless qualifying the resulting policy behavior.
SASY_ALLOW_USER_FUNCTORS	off	--allow-user-functors: admit non-admin native functors with sandboxed (or 1/true/yes/on) only when required sandbox support works. unsandboxed is an explicit development escape hatch. Custom C++ is native code.
SASY_EVALUATOR_BWRAP	enabled where supported	Set exactly 0 to disable evaluator bubblewrap confinement. This prevents sandbox-required non-admin functor admission.
SASY_SECCOMP_PRE_EXEC_DISABLE	unset	Set exactly 1 to disable the Linux pre-exec seccomp layer for debugging. This prevents sandbox-required non-admin functor admission and removes constructor-time protection.
SASY_NIX_RUNTIME_MANIFEST	unset	Nix launcher-supplied immutable runtime closure/tool manifest. Validates and confines compilation to the packaged toolchain. Use the package launcher instead of constructing this setting by hand.

DISABLE_BWRAP=1 is the non-prefixed, host-wide development switch for bubblewrap; it also affects compilation. A host that cannot provide the required sandbox must refuse sandbox-required uploads. The restricted guard engine serves baked profiles and does not gain arbitrary compilation through these variables. The Nix package supplies the toolchain and manifest described in building.

Experimental diagnostics

Variable	Default	Meaning
SASY_FLUSH_INTERVAL_US	1000	Evaluator update coalescing interval in microseconds; 0 disables the timer delay.
SASY_KEEPALIVE_INTERVAL_MS	0	Experimental empty-update keepalive interval; 0 disables it. Intended for performance investigation.
SASY_SERVER_LATENCY_LOG_FILE	unset	Append request timing and session identifiers as JSONL. A failed file open disables logging. Protect the output as operational data.

Build-only and internal controls

Variable	Scope
SASY_POLICY_PACK	Build-time directory consumed by Cargo for a restricted engine’s baked policy pack. Changing it when starting an installed binary cannot change its profiles.
SASY_ASSURED_MODE	Exact value 1 selects a separate assured-runtime tool-pinning/conformance path. It is not a general security-mode switch and does not establish an attestation on its own.
SASY_TOOL_PYTHON3_PATH, SASY_TOOL_PYTHON3_SHA256, SASY_TOOL_SOUFFLE_PATH, SASY_TOOL_SOUFFLE_SHA256, SASY_TOOL_CXX_PATH, SASY_TOOL_CXX_SHA256	Assured-runtime absolute resolved tool paths and lowercase SHA-256 pins; required in that path. Normal startup resolves its tools from the Nix manifest or PATH.
SASY_SKIP_IN_PROC_SANDBOX, SASY_SECCOMP_PRE_EXEC	Engine-to-child protocol markers. The launcher sets these after installing confinement; operators must not set them to claim protection.
SASY_ENGINE_API_KEY	Separate refmon-service development executable’s upstream engine credential fallback. Not the unified sasy serve authentication configuration.

Test-only subprocess markers and SASY_TEST_SKIP_INTERPRETED are test harness controls, not supported deployment settings. Other libraries use their own variables, including logging (RUST_LOG), oracle model/provider configuration (LLM_*), and optional graph mirrors; consult the corresponding component documentation before enabling them.