13.18 Vendor integrations

User stories

• As an engineer, I want every vendor adaptor to share the same retry / circuit-breaker patterns.
• As an ops user, I want to switch vendors via config without code deploy.
• As an admin, I want vendor performance dashboards.

API requirements

• GET /admin/vendors, PUT /admin/vendors/{id} (config + routing).
• GET /admin/vendor-performance.

Data model

• vendor, vendor_credential (encrypted), vendor_routing_rule, vendor_call_log.

UI screens

• Admin: vendor master, routing config, performance dashboard.

Backend services

• Vendor adaptor framework (shared base).
• Circuit breaker library.
• Vendor observability service.

External integrations

• Per vendor — see Section 4.

Test cases

• Vendor adaptor pattern conformance.
• Failover from primary to secondary on outage.
• Performance metrics captured per vendor.

Edge cases

• Vendor API breaking change.
• Failover to secondary with different response schema.
• Credential rotation mid-flow.

Acceptance criteria

• Vendor swap via config only.
• Per-vendor SLA dashboard live.
• Vendor incidents notify on-call.