Source-Driven Development

Agents routinely implement against deprecated, renamed, or re-signatured external APIs using stale training-data recall. The logic looks right, the gates pass, and the bug surfaces at runtime — or worse, silently. This skill forces a four-phase loop that replaces recall with current official documentation, then records a citation so a future reader can detect doc drift.

Protocol: Detect Stack → Fetch Official Docs → Implement → Cite.

Cross-links:

• skills/source-driven-development/detect-stack.md — framework → canonical doc URL reference table.
• skills/build/SKILL.md — /build orchestrator; lists this skill as a recommended sub-skill (Phase 3 implementer).
• skills/recon/SKILL.md — reuse recon's "external-reference investigation" vocabulary for codebase-side lookups; this skill is the docs-side complement.

Trigger Heuristics

The skill auto-triggers when all are true:

1. The prompt, ticket body, or change context mentions a framework/library by name, OR the files being modified import one.
2. The change exceeds the triviality threshold (DEC-4).

DEC-4 — Triviality threshold (Canonical Constants, copied verbatim from the plan):