Reliable and secure external API integration patterns for production-grade services.
Install
npx skillscat add ozerohax/assistagents/coder-system-design-external-api Install via the SkillsCat registry.
SKILL.md
Integrating third-party APIs or partner services
Designing resilience around network and provider failures
Handling provider limits, auth lifecycle, and contract evolution
</when_to_use>
Provider SLA/SLO and rate limit policy
Auth method and credential lifecycle constraints
Error model and retry semantics from provider docs
Business criticality and degradation tolerance
</input_requirements>
Document provider contract, limits, and deprecation policy
Define timeout budget and retry eligibility matrix
Implement resilience layer (timeouts, retries, circuit breaker, limiter)
Add idempotency and duplicate submission controls for mutations
Add observability, alerts, and runbooks before rollout
Verify compatibility continuously with contract checks
</integration_workflow>
Use bounded retries with exponential backoff and jitter for transient failures only
Use circuit breaker with half-open probing to prevent cascade failures
Use client-side throttling and respect 429 plus Retry-After semantics
Use graceful degradation or fallback for non-critical dependency paths
Use async decoupling where provider latency is highly variable
</reliability_patterns>
Use least-privilege scopes and short-lived credentials where possible
Automate secret rotation, revocation, and audit logging
Protect token refresh flows and enforce strict validation
Prevent secret leakage in logs, traces, and error payloads
</security_controls>
No external call path is accepted without explicit timeout
No mutating operation is accepted without idempotency plan
No retry policy is accepted without limits and jitter
No provider integration is accepted without observability signals and alerting
</quality_rules>
Do not apply retries blindly to all errors
Do not ignore provider deprecation/change notices
Do not keep long-lived static credentials without rotation
</do_not>
Integration architecture and failure-mode strategy
Timeout, retry, and rate-limit policy summary
Security controls and secret lifecycle plan
Monitoring signals, SLO impact, and runbook pointers
</output_requirements>
AWS Builders Library: Timeouts, Retries, Backoff with Jitter
Azure Circuit Breaker Pattern
RFC 6585 (429 Too Many Requests)
Stripe Idempotent Requests
RFC 9700 OAuth 2.0 Security BCP
OWASP Secrets Management Cheat Sheet
Pact Consumer Contract Testing