speckit-implement

name	speckit-implement
description	Run agent-native implement orchestration or execute one worker handoff.
compatibility	Requires spec-kit project structure with .specify/ directory
metadata	{"author":"github-spec-kit","source":"workflow-preset:commands/speckit.implement.md"}

Input

$ARGUMENTS

Optional runtime hint: agent-runtime=<spec-kit-integration-key>.

Mode

• Core mode: no handoff JSON path in $ARGUMENTS.
• Worker mode: .json handoff path in $ARGUMENTS or Use handoff JSON <path>.
• Forbidden: external dispatch scripts, workflow runners, inline worker execution.

Authority

• Core Agent is the orchestrator: build context-index.json, assemble handoff-manifest.json, dispatch isolated runs, review receipts, update tasks.md only during task commit, and run integration verification.
• Vertical Planner Agent is the capability planner: plan exactly one vertical_capability, produce shard plans plus handoff/context digest drafts, and never execute implementation or write the final manifest.
• Worker Agent is the handoff executor: execute exactly one handoff and never edit tasks.md, create handoffs, or dispatch workers.

Core Agent

• Follow the lifecycle and runtime isolation contract in tests/contracts/speckit-cross-agent-subagents.md.
• Map planned U design objects to concrete source, test, fixture, configuration, and receipt paths before worker execution.
• Use isolated_subagent only when the runtime provides isolated subagent/subsession execution.
• Otherwise use manifest execution_mode: manual_fresh_worker_session.
• If isolation is unavailable or unknown, write the manifest and handoffs, then stop with Worker-mode instructions.
• Consume planner outputs and worker receipts, not worker conversation history.

Vertical Planner Agent

• Read only tasks.md, context-index.json, and allowed planning artifacts.
• Preserve tasks.md order, lifecycle dependencies, capability boundaries, and Change Scope Granularity.
• Put unresolved shard, context, asset binding, or path ambiguity into context_gaps.
• Emit drafts that validate against the handoff schema before Core assembly.

Worker Agent

• Reject non-existent handoff paths.
• Reject handoffs not listed in handoff-manifest.json.
• Verify contract_type is speckit.implement.handoff.v2.
• Load context_digest_path before editing.
• Stop before editing when context_gaps is not empty.
• Execute only task_ids.
• Read only allowed_read_paths.
• Write only allowed_write_paths.
• Write task_status_update.receipt_path as speckit.implement.receipt.v1.
• Do not edit tasks.md.

Contract References

• Runtime, shard, context digest, path, asset binding, dispatch, Worker Prompt, and review receipt rules: tests/contracts/speckit-cross-agent-subagents.md.
• Manifest schema: schemas/speckit.implement.manifest.v1.schema.json.
• Handoff schema: schemas/speckit.implement.handoff.v2.schema.json.
• Receipt schema: schemas/speckit.implement.receipt.v1.schema.json.
• Cross-field validation: validators/speckit_implement_contract.py.

Runtime Stops

• Stop on missing handoff files, unlisted handoffs, non-empty context_gaps, schema mismatch, write paths outside allowed_write_paths, or attempts to update planning artifacts from Worker mode.
• Stop instead of inventing validation strategy, adding lifecycle roles, changing requirements, updating contracts, widening scope, or adding standalone validation planning artifacts.