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API DESIGN / 18-minute exercise
Design a reliable verification result
Specify explicit states and errors before building an API.
REAL-WORLD SCENARIO
Work through the decision.
A relying service receives success, expiry, and service-unavailable outcomes from a trust provider.
Your objective
Specify consistent and safe response semantics.
Deliverable: A typed result schema with explicit errors and one-time consumption.
Activity steps
0 of 3 steps complete
Your work is saved on this device only.
Worked example
outcome: verified | rejected | expired | unavailable; challengeId: opaque; expiresAt: timestamp; boundActionId: opaque; consumed: boolean.
Quality check
- Define all terminal outcomes.
- Bind the result to the intended action.
- Make unknown states fail safely.
GO DEEPER
Continue with the source guide.
The companion guide provides the reasoning and trade-offs behind the exercise.
Read the companion guide