feat: Add OpenAPI-based typed HTTP client generation

README.md

@@ -34,7 +34,7 @@ Whether you're scaffolding a greenfield service from an OpenAPI contract, evolvi
 
 ## Features
 
-- **Code generation from OpenAPI 3.0** — reads any valid OpenAPI 3.0 spec (JSON or YAML) and emits a complete, compilable MoonBit project with typed route registrations, request decoders, and handler stubs
+- **Code generation from OpenAPI 3.0** — reads any valid OpenAPI 3.0 spec (JSON or YAML) and emits a complete, compilable MoonBit project with typed route registrations, request decoders, handler stubs, and a typed HTTP client
 - **Regeneration-safe** — user-owned handler files are never overwritten on subsequent `generate` runs; only files carrying the `// Code generated by mapi. DO NOT EDIT.` header are updated
 - **Spec drift detection** — `mapi diff` compares your current spec against the saved `.mapi/state.json` and surfaces added, removed, and unchanged routes before you regenerate
 - **Host-adapter architecture** — the runtime core (`lib/`) is completely decoupled from I/O; any execution environment (Bun, Node, Deno, native Wasm) can be plugged in by implementing a thin host adapter
@@ -55,7 +55,7 @@ Or add to your `moon.mod.json` directly:
 ```json
 {
   "deps": {
-    "cogna-dev/mapi": "0.1.0"
+    "cogna-dev/mapi": "0.1.1"
   }
 }
 ```
@@ -79,8 +79,11 @@ my-api/
 ├── moon.mod.json
 ├── src/
 │   ├── generated/              # DO NOT EDIT — regenerated by mapi
-│   │   ├── routes.mbt          # Route registrations, request decoders
-│   │   ├── models.mbt          # Request / response types
+│   │   ├── schemas.mbt         # OpenAPI schema models
+│   │   ├── operations.mbt      # Typed operation inputs / outputs
+│   │   ├── contract.mbt        # Handler contract for server implementation
+│   │   ├── router.mbt          # Route registrations and server glue
+│   │   ├── client.mbt          # Typed HTTP client generated from spec
 │   │   └── moon.pkg
 │   └── handlers/               # Your code — never overwritten
 │       ├── get_users.mbt
@@ -212,6 +215,20 @@ assert_eq!(not_found.status, 404)
 
 ---
 
+## Generated Typed HTTP Client
+
+Each generated project now includes `src/generated/client.mbt`, which gives you a static-typed API client derived directly from the same OpenAPI contract used for server scaffolding.
+
+- One typed client method per operation (`ApiClient::list_pets`, etc.)
+- Strongly typed request input (`ListPetsInput`) and response output (`ListPetsResponse`)
+- Path/query/body request shaping generated from OpenAPI parameters and requestBody
+- JSON response decoding into generated MoonBit types
+- Deterministic status-code handling (preferred success status from OpenAPI, or fallback to any `2xx`)
+
+`ApiClient` is transport-agnostic: provide an `ApiTransport` with a `send` function that receives a `RequestEnvelope` and returns a `ResponseEnvelope`. This keeps the generated client reusable across Bun, Node, Deno, native hosts, and in-memory tests.
+
+---
+
 ## Architecture
 
 ```
@@ -224,8 +241,8 @@ assert_eq!(not_found.status, 404)
                        ▼
 ┌─────────────────────────────────────────────────────┐
 │  Generated layer  (src/generated/)                  │
-│  routes.mbt · models.mbt                            │
-│  Typed route registrations + request decoders       │
+│  schemas · operations · contract · router · client  │
+│  Typed server glue + typed HTTP client              │
 └──────────────────────┬──────────────────────────────┘
                        │ calls
                        ▼