Environment Variables¶

All teststop behavior can be controlled via environment variables — no config file needed.

Reference¶

Variable	Default	Description
`TESTSTOP_CLI`	`auto`	Which AI CLI to use
`TESTSTOP_MODEL`	(empty)	Model to pass to the AI CLI
`TESTSTOP_SANDBOX`	`auto`	Sandbox isolation mode

`TESTSTOP_CLI`¶

Controls which AI adapter teststop uses.

Value	Behavior
`auto` (default)	Try `claude` first, then `copilot`; error if neither found
`claude`	Use Claude CLI; error if not on PATH
`copilot`	Use GitHub Copilot CLI; error if not on PATH

TESTSTOP_CLI=claude teststop run
TESTSTOP_CLI=copilot teststop run

`TESTSTOP_MODEL`¶

Passed as --model <value> to the AI CLI. Only applies to adapters that support model selection.

CLI	Support	Example
`claude`	✅ Yes	`TESTSTOP_MODEL=claude-opus-4-7`
`copilot`	❌ Ignored	Model is controlled by GitHub Copilot subscription

TESTSTOP_MODEL=claude-sonnet-4-6 teststop run
TESTSTOP_MODEL=claude-opus-4-7 teststop run --depth aggressive

If not set, the Claude CLI uses its configured default model.

`TESTSTOP_SANDBOX`¶

Controls whether teststop runs the AI CLI inside an Apple Container VM.

Value	Behavior
`auto` (default)	Use container if `container system status` reports running; direct otherwise
`required`	Error immediately if container is not running
`none`	Always run directly — bypass container detection

# CI/CD environments (container not available)
TESTSTOP_SANDBOX=none teststop run

# Enforce isolation — fail if container unavailable
TESTSTOP_SANDBOX=required teststop run

See Sandbox Isolation for detailed explanation.

Setting Variables¶

Per command¶

TESTSTOP_CLI=claude TESTSTOP_SANDBOX=none teststop run

In `.env` files (with direnv or similar)¶

# .envrc
export TESTSTOP_CLI=claude
export TESTSTOP_MODEL=claude-sonnet-4-6
export TESTSTOP_SANDBOX=none

In GitHub Actions¶

- name: Run teststop
  env:
    TESTSTOP_CLI: claude
    TESTSTOP_SANDBOX: none
  run: teststop run --output json --threshold 80

In shell profile (permanent)¶

# ~/.zshrc or ~/.bashrc
export TESTSTOP_CLI=claude
export TESTSTOP_SANDBOX=none

No Config File¶

teststop intentionally has no configuration file. The six design non-negotiables include:

ZERO CONFIGURATION — teststop run must work with no setup on any project.

Environment variables are the only customization layer.