API Design Builder
What is API design?
API design turns a client workflow into a stable contract: resources, operations, authorization, retry behavior, responses, and compatibility guarantees.
Step 1
Model
Choose an operation, shape its path and execution contract, then model client traffic, dependency latency, and retry amplification.
Step 2
Observe
Use the readiness score, generated OpenAPI document, and request-path forecast to find ambiguous ownership, unsafe retries, missing outcomes, and overload risk.
Step 3
Challenge
Switch a write from synchronous to asynchronous, return 202 Accepted, then inject a retry storm and decide which idempotency, status, and backpressure semantics must change.
Design the behavior clients depend on
Shape each operation, validate retry and response semantics, then pressure-test the request path before publishing the contract.
Contract loop
Shape the operation
Every choice updates validation and the generated OpenAPI document.
Execution contract
Parameters
Path, query, and header inputs
Responses
Observable outcomes for clients
Pressure loop
Challenge the request path
Inject demand and dependency failure to expose unsafe retry behavior.
Clients
1,200 rps
+24 retry rps
API service
19% saturated
98 in flight
Dependency
80 ms
Inventory and payment path
1,224 rps
Effective load
88 ms
Estimated p99
99.97%
Availability
100%
Contract readiness