Engine environment

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, 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	Relation names forwarded to Soufflé’s magic-set option, a Datalog optimization that rewrites rules to compute only the facts a query needs. 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. A restricted engine serves only its baked profiles and does not gain the ability to compile a policy through these variables. The Nix package supplies the toolchain and manifest described in build the engine.

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 makes the engine refuse to start unless every external tool it runs is named by an absolute path and matches a SHA-256 pin, given in the SASY_TOOL_* variables below. It pins tools; it is not a general security switch and produces no attestation.
SASY_TOOL_PYTHON3_PATH, SASY_TOOL_PYTHON3_SHA256, SASY_TOOL_SOUFFLE_PATH, SASY_TOOL_SOUFFLE_SHA256, SASY_TOOL_CXX_PATH, SASY_TOOL_CXX_SHA256	The absolute paths and lowercase SHA-256 pins that SASY_ASSURED_MODE=1 requires. Ordinary startup ignores these and resolves its tools from the Nix manifest or PATH.
SASY_SKIP_IN_PROC_SANDBOX, SASY_SECCOMP_PRE_EXEC	Internal markers the engine passes to a child process it has already confined. Setting them yourself claims a protection that was never installed.

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), the model and provider settings for the optional LLM-backed policy predicate (LLM_*), and optional graph mirrors; consult the corresponding component documentation before enabling them.