idd-skill: Instructions file for GitHub Copilot

IDD (Issue-Driven Development) — Shared Definitions (Runtime Core)

This file holds the core runtime-critical IDD definitions: claim ownership, marker authentication, state parsing, and pre-mutation safety gates.

For reference content and implementation detail, see idd-overview-appendix.instructions.md.

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Claim format

Post this comment to an issue to claim it, heartbeat it, or take it over. The HTML comment token must remain the first bytes of the body; the visible note is for humans:

<!-- claimed-by: {agent-id} {claim-id} supersedes: {prior-claim-id|none} {ISO8601-timestamp} branch: {branch-name} -->

_{agent-id}: issue claim — IDD automation marker. Do not edit._

Important: operational marker bodies are HTML comments. gh issue comment and gh api -f body= silently reject HTML-only bodies (and mishandle @-prefixed values) — always include the visible note and post via direct HTTP POST with a JSON body; see docs/idd-helper-scripts.md for the full gh api pitfalls. When helper runtime is enabled, the post-idd-marker helper (--type claim --target issue <number> --apply plus the claim fields) posts this marker through that JSON path (dry-run without --apply); the direct POST is the fallback.

Every new HTML-comment operational marker must include a short visible note after the token: review-watermark/review-baseline use the phase-specific formats in idd-review-snapshot.instructions.md; claimed-by/unclaimed-by use the notes shown here. Hidden-only legacy claimed-by/unclaimed-by comments remain valid for parsing/migration, but never create new hidden-only claim comments.

• {agent-id} is a tool or agent identifier shared across concurrent sessions of the same agent type. For auditability, appending a unique session token is recommended (e.g., copilot-8122ca35). {claim-id} remains the authoritative ownership token — agent-id alone never proves ownership.
• {claim-id} is an opaque unique token for one active claim lineage and is the portable ownership token used with trusted actor and session-record checks. Generate a fresh value on every fresh claim or stale takeover. Reuse the same {claim-id} only for heartbeats of that already-verified claim. Reading an existing {claim-id} from issue comments does not by itself prove ownership; the current session must have recorded that token before the revalidation step.
• {prior-claim-id} is none for a fresh claim on an unclaimed issue. For a stale-claim takeover, set it to the currently active claim's {claim-id}.