external-api-integrationlisted

# External API Integration Use only after the active phase identifies an external-provider boundary. Inherit its authority, artifact, review, proof, output, and completion contract; do not select a work mode or authorize provider actions here. Core invariant: persist one local operation identity before side-effecting I/O, reuse it across attempts and observation paths, and retain an ambiguous outcome until authoritative lookup, callback, or reconciliation resolves it. Load one branch: - outbound HTTP deadlines, retries, rate limits, pagination, or response bounds -> [http-resilience.md](references/http-resilience.md); - OAuth, token lifecycle, scope, or credential selection -> [authentication.md](references/authentication.md); - callback/webhook verification, identity, ordering, or replay -> [webhooks.md](references/webhooks.md); - side-effect convergence, reconciliation, migration, or proof -> [convergence-and-proof.md](references/convergence-and-proof.md).