APIs that are a pleasure to integrate.
Type the capability you need. The API Designer preset shapes a prompt that produces a clean, consistent, well-documented interface.
Ask an AI to "design an API" and you get inconsistent naming, vague error handling, and no thought for versioning or pagination. Awkward APIs leak their flaws into every client that touches them, and changing them later is painful.
The API Designer preset pre-tunes the pipeline to produce prompts grounded in interface design: clear resource modelling, consistent naming, sensible status codes, error contracts, pagination, and versioning. Every generated prompt asks for the contract and the rationale, not just endpoints.
Type a sentence. Get an expert prompt.
Design a REST API for a team task-management app.
Role: You are a senior API designer specifying a REST API for a team task-management application. Context: The API will be consumed by web and mobile clients and by third-party integrations. Consistency, predictability, and a clean upgrade path matter more than cleverness. Task: Design the core resources and endpoints for tasks, projects, and assignments. Define the request and response shapes, status codes, error format, pagination, filtering, and a versioning strategy. Constraints: - Use noun-based, plural resource paths and standard HTTP verbs. - Define a single consistent error envelope with a machine-readable code and a human message. - Use cursor-based pagination and document the parameters. - Make the design idempotent where it should be, and explain authentication expectations. - Favour conventions over inventions; justify any deviation. Format: Return a resource table, then an endpoint reference (method, path, purpose, key params), then example request and response bodies for two endpoints, then a short note on versioning and errors.
Tuned for api designer work.
Consistent conventions
Prompts enforce predictable naming, verbs, and resource modelling across the whole surface.
Error contracts
Generated prompts demand a single, machine-readable error format rather than ad-hoc messages.
Pagination and filtering
Each prompt specifies how clients page, filter, and sort large collections.
Versioning strategy
Prompts insist on a clear upgrade path so the API can evolve without breaking clients.
Worked examples
Every prompt asks for concrete request and response bodies, not just abstract schemas.
Three steps, about 100 seconds.
Type one sentence
Describe the capability or service you want an interface for in plain language.
20 agents refine
A pipeline of 20 on-device specialists shapes a precise API design prompt in about 100 seconds.
Copy into your AI
Paste the finished prompt into ChatGPT, Claude, Gemini, or Copilot to produce the spec.
API Designer preset questions.
Does it design the API directly?+
No. It generates the design prompt. You paste it into your AI assistant to produce the specification.
Does it cover GraphQL and gRPC too?+
Yes. Name the style in your sentence and the pipeline shapes the prompt for REST, GraphQL, or gRPC conventions.
Is my design idea kept private?+
Yes. Everything runs on-device with Apple Intelligence, so your idea and the generated prompt never leave your iPhone.
Can it produce an OpenAPI spec?+
Yes. Request OpenAPI output in your sentence and the generated prompt will ask the AI for it.
How many prompts can I generate for free?+
Five runs a day on the free tier. Pro removes the limit at £4.99 a month, £29.99 a year, or £59.99 for lifetime access.
Explore related roles.
Build your api designer prompts on-device.
Free 5 runs a day. Pro from £4.99/mo, £29.99/yr, or £59.99 once. Nothing leaves your iPhone.