| prompt | The instruction for ZERO to execute. Mutually exclusive with prompt-file. | no | "" |
| prompt-file | Path (relative to working-directory) to a file whose contents are the prompt. | no | "" |
| provider | Provider id to activate (for example openai, anthropic, gemini, ollama, or any configured OpenAI-/Anthropic-compatible endpoint). Optional when the repository already carries a .zero/config.json with an active provider. | no | "" |
| api-key | The provider API key. Pass it from a repository or organization secret; it is exported only for the ZERO step and never written to the log. | no | "" |
| api-key-env | Name of the environment variable the chosen provider reads its key from (for example OPENAI_API_KEY or ANTHROPIC_API_KEY). When set together with api-key, that variable is exported only for the ZERO step. Leave the action provider-agnostic by passing the env name your provider expects rather than hardcoding one here. | no | "" |
| model | Model id to use for the run. Defaults to the resolved provider's default. | no | "" |
| mode | Run mode passed to `zero exec --mode` (for example smart, deep, or fast). | no | "" |
| auto | Autonomy ceiling passed to `zero exec --auto` (low, medium, or high). Defaults to the conservative `low` so an unattended CI run cannot take high-impact actions implicitly. | no | low |
| self-correct | When true, allow ZERO to request a stronger model mid-run if it hits a wall (maps to `zero exec --allow-escalation`). | no | false |
| add-dir | Newline- or comma-separated extra write roots granted to the run (each passed as `zero exec --add-dir`). The checked-out repository is always writable; everything else stays read-only unless listed here. | no | "" |
| worktree | When true, run inside an isolated git worktree (`zero exec --worktree`). | no | false |
| output-format | Output format for `zero exec` (text, json, or stream-json). Defaults to stream-json, which is captured to a file and exposed as the output-file output and uploaded by the caller if desired. | no | stream-json |
| post-to | Optional destination for a run summary after ZERO finishes: `pr-comment` posts to the triggering pull request using github-token, `slack` posts to slack-webhook-url, or `none` (default) posts nowhere. | no | none |
| slack-webhook-url | Slack incoming-webhook (or generic webhook) URL used when post-to is slack. Pass it from a secret; it is never written to the log. | no | "" |
| github-token | Token used to post a PR comment when post-to is pr-comment. Defaults to the workflow's GITHUB_TOKEN; the workflow must grant pull-requests: write. | no | ${{ github.token }} |
| working-directory | Directory to run ZERO in. Defaults to the workspace root. | no | ${{ github.workspace }} |
| zero-version | ZERO release version/tag to install (for example v1.2.3 or latest). Defaults to the ref this action was resolved at, falling back to latest. | no | "" |
| zero-repo | Repository to install the ZERO release from (owner/repo). | no | Gitlawb/zero |