Environment Variables

Atomic accepts environment variables for configuration, provider credentials, and subprocess context. Atomic-prefixed application variables take precedence over their legacy Pi aliases when both are set.

Application configuration

Atomic variable	Legacy alias	Purpose
`ATOMIC_CODING_AGENT_DIR`	`PI_CODING_AGENT_DIR`	Agent/config directory; default `~/.atomic/agent`
`ATOMIC_CODING_AGENT_SESSION_DIR`	`PI_CODING_AGENT_SESSION_DIR`	Session directory; `--session-dir` takes precedence
`ATOMIC_PACKAGE_DIR`	`PI_PACKAGE_DIR`	Package directory override
`ATOMIC_OFFLINE`	`PI_OFFLINE`	Disable startup network operations
`ATOMIC_SKIP_VERSION_CHECK`	`PI_SKIP_VERSION_CHECK`	Skip automatic startup version checks; explicit self-update still checks
`ATOMIC_TELEMETRY`	`PI_TELEMETRY`	Enable/disable install/update telemetry
`ATOMIC_REDUCED_MOTION`	`PI_REDUCED_MOTION`	Use static reduced-motion presentation

PI_CACHE_RETENTION=long is a provider/upstream prompt-cache option and intentionally has no Atomic-prefixed alias. VISUAL and EDITOR select the Ctrl+G external editor when externalEditor is unset.

Provider credentials

Provider keys include ANTHROPIC_API_KEY, OPENAI_API_KEY, AZURE_OPENAI_API_KEY, GEMINI_API_KEY, AWS/Bedrock credentials, and the variables listed in Providers. ANTHROPIC_AUTH_TOKEN is a distinct header-only bearer credential for Anthropic-compatible gateways: Atomic sends Authorization: Bearer … without requiring or inventing an API key, including normal turns, isolated execution, branch summaries, and Verbatim Compaction. Custom headers remain independent.

Bash session environment

Every built-in, factory-created, direct, foreground/background, workflow-stage, and isolated bash execution receives one execution-time snapshot:

Atomic variable	Exact Pi alias	Value
`ATOMIC_SESSION_ID`	`PI_SESSION_ID`	Active session ID
`ATOMIC_SESSION_FILE`	`PI_SESSION_FILE`	Active JSONL file; omitted for unsaved/ephemeral sessions
`ATOMIC_PROVIDER`	`PI_PROVIDER`	Active provider; omitted when no model is selected
`ATOMIC_MODEL`	`PI_MODEL`	Active model ID; omitted when no model is selected
`ATOMIC_REASONING_LEVEL`	`PI_REASONING_LEVEL`	Active reasoning level

Atomic clears these ten reserved names before overlaying the current snapshot, preventing stale metadata from another session or workflow stage. Unrelated inherited/caller variables remain intact. The snapshot is taken when execution begins, so a resumed session or later model change is reflected. SDK createBashTool() exposes it by default; set exposeSessionEnvironment: false to opt out. See Using Atomic and RPC direct bash for execution and streaming behavior.

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Customization

Reference

Programmatic Usage

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Changelog

Environment variables

Environment Variables

Application configuration

Provider credentials

Bash session environment

​Environment Variables

​Application configuration

​Provider credentials

​Bash session environment

Environment Variables

Application configuration

Provider credentials

Bash session environment