Environment variables

Core

Variable	Maps to	Default
`STASO_API_KEY`	`st.init(api_key=...)`	Required
`STASO_AGENT_NAME`	`st.init(agent_name=...)`	Required
`STASO_BASE_URL`	`st.init(base_url=...)`	`https://api.staso.ai`
`STASO_ENVIRONMENT`	`st.init(environment=...)`	`default`
`STASO_WORKSPACE_SLUG`	`st.init(workspace_slug=...)`	`default`
`STASO_SESSION_ID`	Process-default trace grouping identifier.	Generated during `st.init()`
`STASO_DEBUG`	Enables SDK debug logging when truthy.	Unset
`STASO_AUTO_PATCH`	Set to `false` to stop auto-patching installed OpenAI and Anthropic SDKs.	`true`

STASO_AUTO_PATCH affects only the two native launch providers. Explicit @st.agent and @st.tool instrumentation is still required for the supported root and tool shape.

Launch quickstart

Use this minimum environment for the pinned OpenAI sample:

Variable	Purpose
`STASO_API_KEY`	Staso key with `traces:write`; add `guard:evaluate` when Guard is configured.
`OPENAI_API_KEY`	Provider key used by the sample OpenAI client.
`STASO_AGENT_NAME`	Process-level agent name, for example `launch-quickstart-agent`.
`STASO_ENVIRONMENT`	Environment label shown with the trace, for example `production`.
`STASO_WORKSPACE_SLUG`	Dashboard workspace that should receive the trace, for example `default`.
`STASO_SESSION_ID`	Stable grouping identifier, set to `launch-quickstart-first-trace` for this sample.

Provider patch status is observed only after the backend stores a provider LLM span such as provider=openai or provider=anthropic. Install success, dashboard clicks, and local initialization are not enough evidence by themselves.

Capture policy

Variable	Category	Default
`STASO_CAPTURE_REQUEST`	`request`	`true`
`STASO_CAPTURE_SYSTEM_PROMPT`	`system_prompt`	`true`
`STASO_CAPTURE_TOOL_SCHEMA`	`tool_schema`	`true`
`STASO_CAPTURE_TOOL_ARGUMENTS`	`tool_arguments`	`true`
`STASO_CAPTURE_OUTPUT`	`output`	`true`
`STASO_CAPTURE_MESSAGES`	Deprecated fallback for `request` and `system_prompt` only.	Unset

Values are case-insensitive and must be one of 1/0, true/false, yes/no, or on/off. Invalid configured values fail initialization instead of silently enabling capture.

The categories govern request content, standalone system prompts, tool/structured-response schemas, tool arguments, and assistant/tool/decorator output respectively.

Precedence for each category is the explicit st.init(capture_<category>=...) argument, the matching category variable, the deprecated messages control for request and system_prompt only, then true. See SDK setup for field classification and overlap rules.

Guard

Variable	Description	Default
`STASO_GUARD_ENABLED`	Set to `false` to disable Guard checks in patched native provider integrations.	`true`
`STASO_GUARD_FAIL_CLOSED`	Set to `1` or `true` to return `block` when no policy decision is available.	Unset, so checks fail open
`STASO_GUARD_TIMEOUT`	Timeout for `st.guard(...)` HTTP requests, in seconds.	`10.0`
`STASO_GUARD_BATCH_TIMEOUT`	Absolute deadline for one provider-response proposal batch, in seconds.	`10.0`
`STASO_GUARD_MAX_CONCURRENCY`	Maximum concurrent checks in one provider-response proposal batch, capped at `8`.	`4`

CLI-agent hooks

staso setup persists the five non-secret capture variables for an explicit selection. It stores the API key separately in Staso's user-only credential file and writes only STASO_CREDENTIAL_ID into hook configuration. An injected STASO_API_KEY remains available for CI and containers.