Imported from tommy-ca/grok-build-plugins (long-horizon-swarm/skills/openspec-intent-flow/SKILL.md). Install upstream with npx skills add tommy-ca/grok-build-plugins --skill openspec-intent-flow. Copyright stays with the author.

OpenSpec intent-driven flow

OpenSpec is the on-disk spec language. The swarm overlay is the execution engine. This skill binds them. It does not invent types. It does not replace poteto-mode.

Builds on long-horizon-swarm, planner-worker-split, field-guide, review-lenses, and show-me-your-work.

When

• User names OpenSpec, /opsx:*, intent-driven, spec-driven, or "agree before you build".
• The long-horizon overlay is active and a Spec artifact would otherwise be a free-form spec blob.
• The work is a program with observable behaviour and decisions that should survive the change.

Not for a one-line bug-fix. That stays on Bug fix.

Disk

If openspec/config.yaml is missing, write:

schema: intent-driven

Then use this layout. Do not invent a twin.

openspec/specs/<capability>/spec.md
openspec/changes/<change>/proposal.md
openspec/changes/<change>/specs/<capability>/spec.md
openspec/changes/<change>/design.md
openspec/changes/<change>/adr.md
openspec/changes/<change>/tasks.md
adr/NNNN-<slug>.md
long-horizon/<change>/

The change id is the overlay program id and the TaskTree root id. long-horizon/<change>/ holds extras and, when bun can run orch.ts, the orch unit store. HostStore is the board only when orch cannot run.

Gates

explore? -> proposal -> (specs || design) -> adr -> tasks -> apply -> archive

Refuse to spawn workers or implementers until tasks.md exists and adr.md is present and validates. The propose gate (proposal → specs/design → adr → tasks) stays strictly serial. specs and design may proceed in parallel after proposal (existing gate). If tasks.md is missing, implementer spawn is refused naming the tasks / propose gate.

Parallel bands and N-briefs apply

After tasks.md exists and passes openspec validate --strict:

• N-briefs fan-out: Horizon/Drove MAY spawn N briefs for independent P-parallel leaves under ## Parallel band headings.
• Exclusive write targets: Each brief/arm runs in a distinct exclusive worktree (or conceptKey write target). Never dual-write sibling trees.
• Join on evidence: Horizon/Drove joins arms on evidence paths (e.g., briefs/herd/<arm>-evidence.md), not on first-idle alone.
• True gates stay serial: Serial numbered sections (## 0. Preconditions, ## 1. Validate, ## 2. STOP handoff, ## 3. Archive) and Todd-go apply authority remain true gates. Soft-after leaves sequence after their prerequisites without forcing unrelated P-parallel tasks into a fake total order.
• No Drove caps invented: Do not document or invent Drove max_concurrent standing-order numbers inside gbp product text; concurrency is governed by orchestrator capacity and exclusive worktrees.
• No claim from propose alone: Never claim parallelism-sync done from propose prose alone; completion is gated on post-apply Prove bars.

Binding

Read references/openspec-binding.md in this plugin. Cites fleet OpenSpec × pstack orch compose at /workspace/fleet-external-agents/openspec-pstack-orch/ (propose gated B8, parallel after tasks, exclusive worktrees; no vendor copy; no Drove quotas). Short form:

• capability kebab-case = conceptKey
• each #### Scenario = one Brief.ACCEPTANCE line
• each tasks.md checkbox = one Unit
• design.md = program DesignDoc
• long-horizon/<id>/design-docs/<conceptKey>.md = per-key DesignDoc
• adr.md row = show-me-your-work row
• archive = Close step + merge deltas into openspec/specs/ + Field Guide curate

Commands as playbook steps, not a second router

If the OpenSpec CLI is on PATH, prefer openspec status --change <id> and openspec archive <id> over hand-merging. If it is not, merge by the delta headers and record cli: absent in the trail.

Git discipline

Proposal artifacts land on the integration branch before apply starts. Apply runs in exclusive worktrees. Archive waits until implementation is on the integration branch. This is sequence-verifiable-units plus playbooks/shipping.md, not a new VCS.

Planner vs worker

Planner writes proposal, specs, design, adr, tasks, Field Guide index. Worker implements one checkbox. Worker may append a Field Guide surprise. Worker may not edit proposal, design, adr, or openspec/specs/.