The YAML format of a workflow's file, which read_workflow returns and save_workflow takes: stages, after, base, model and teams.

# Workflow files

A workflow's file is YAML: an optional `description`, then `stages`. The workflow's name is not in the file. Unknown fields are refused.

| Field | Meaning |
|---|---|
| `name` | One line, unique in the workflow. |
| `after` | The names of the stages whose outputs it gets; it starts once all of them have finished. Absent means the previous stage in the list, and for the first stage none, so a file without `after` is a chain. `[]` means it starts from the brief. |
| `base` | `parent`, the default: branch from the commit its one `after` stage finished at, or for a stage with none, from where the workflow was started. `main`: branch from the default branch. Refused on a stage with more than one `after` stage, which always branches from the default branch and is told the branches it can merge. |
| `model` | Also picks the vendor: `gpt-*` models run on Codex, `gemini-*` models on Antigravity, every other model on Claude Code. |
| `prompt` | The stage agent's instructions. |
| `agents` | In place of `model`: a list of at least two, each with `name`, `model` and `prompt`, that runs the stage as a team. They work in the stage's one task and worktree and talk through a shared board; each gets the stage's `prompt` and then its own, and the first agent finishes the stage. |

Every stage runs as its own task. Exactly one stage is final (no other stage comes after it), and cycles are refused.

```yaml
description: Build a change, review and test it in parallel, then fix what they found.
stages:
  - name: Build
    model: claude-opus-5-5
    prompt: Implement the brief.
  - name: Review
    after: [Build]
    model: gpt-6.1-sol
    prompt: Review the Build stage's work and list the problems.
  - name: Test
    after: [Build]
    model: gemini-4-argon-high
    prompt: Exercise the change and report what fails.
  - name: Fix
    after: [Review, Test]
    agents:
      - name: fixer
        model: claude-opus-5-5
        prompt: Fix every problem the reports list.
      - name: checker
        model: gpt-6.1-sol
        prompt: Check each fix as the fixer lands it.
    prompt: Merge the branches you are given and address both reports.
```