# Headless

No interactive user: infer everything, ask nothing, but never invent — record inferences as `assumptions[]` and gaps that need a human as `open_questions[]`. Detect headless from a `headless: true` flag, a non-interactive / no-TTY invocation, an activation hook that declares it, or a first message that pre-supplies all inputs and asks for an artifact path back; when ambiguous, default to interactive.

Drive the run from the payload in the first message — `intent`, `altitude`, `purpose`, the driving input (spec package / PRD / raw intent / brownfield path), a parent spine path at lower altitude, and `doc_workspace` if a specific folder is required. Infer anything absent from the inputs or workspace; don't invent stack, constraints, or scope to fill a gap. You still verify named tech on the web (you can't ask, but you can check) and still drive every write through the shared `{project-root}/_acl/scripts/memlog.py`. Run the full Reviewer Gate (`references/reviewer-gate.md`) non-interactively: `scripts/lint_spine.py` plus **every `{workflow.finalize_reviewers}` lens as a parallel subagent** (and any ad-hoc lens the spine's criticality warrants). Headless skips only the human picking from the menu — never the reviewers themselves; apply the clear fixes and record anything unresolved in `open_questions[]`. For a true authority collision, list it in `conflicts_with_prior_decisions[]`. For the Validate intent, always write the report to `{doc_workspace}` and add `"offer_to_update": true`. If intent stays ambiguous after inference, halt blocked.

End with JSON only, omitting keys for artifacts not produced — the shape below is the fully-produced (`complete`) case; a `blocked` run produces no spine, so it omits `spine`, `memlog`, and `companions` entirely (see the note under the block):

```json
{
  "status": "complete | partial | blocked",
  "intent": "create | update | validate",
  "altitude": "initiative | feature | epic",
  "purpose": "build-substrate | discussion",
  "doc_workspace": "<resolved run folder>",
  "spine": "{doc_workspace}/ARCHITECTURE-SPINE.md",
  "memlog": "{doc_workspace}/.memlog.md",
  "companions": [],
  "assumptions": [],
  "open_questions": [],
  "conflicts_with_prior_decisions": [],
  "reason": "<one line, only when blocked>"
}
```

`complete` stands alone · `partial` (spine produced, but `open_questions[]` non-empty or critical inputs inferred) means review before downstream use · `blocked` means no spine produced — return only `status`, `intent`, `reason`, and `doc_workspace` (if bound), omitting `spine`, `memlog`, `companions`, and the artifact arrays that don't exist.