api-sdk-generator

API SDK & Codegen Skill

Generate production-quality client libraries and SDK code for any API in any language.

SDK Structure (any language)

sdk/
├── client.{ext}          — main client class with base URL, auth, retry
├── resources/
│   ├── users.{ext}       — one file per API resource
│   ├── orders.{ext}
│   └── ...
├── models/
│   ├── user.{ext}        — request/response data models
│   └── ...
├── errors.{ext}          — typed error classes
└── utils/
    ├── retry.{ext}
    └── pagination.{ext}

Base Client Pattern

Python

import httpx
from typing import Optional
import time

class APIClient:
    def __init__(self, api_key: str, base_url: str = "https://api.example.com/v1"):
        self.base_url = base_url
        self._headers = {
            "Authorization": f"Bearer {api_key}",
            "Content-Type": "application/json",
            "User-Agent": "example-sdk-python/1.0.0"
        }
        self._client = httpx.Client(timeout=30.0)

    def _request(self, method: str, path: str, **kwargs) -> dict:
        url = f"{self.base_url}{path}"
        for attempt in range(3):
            try:
                resp = self._client.request(method, url, headers=self._headers, **kwargs)
                if resp.status_code == 429:
                    retry_after = int(resp.headers.get("Retry-After", 2 ** attempt))
                    time.sleep(retry_after)
                    continue
                resp.raise_for_status()
                return resp.json()
            except httpx.HTTPStatusError as e:
                raise APIError(e.response.status_code, e.response.json()) from e
        raise RateLimitError("Max retries exceeded")

TypeScript

class APIClient {
  private readonly baseUrl: string;
  private readonly headers: Record<string, string>;

  constructor(apiKey: string, baseUrl = 'https://api.example.com/v1') {
    this.baseUrl = baseUrl;
    this.headers = {
      'Authorization': `Bearer ${apiKey}`,
      'Content-Type': 'application/json',
    };
  }

  async request<T>(method: string, path: string, body?: unknown): Promise<T> {
    const res = await fetch(`${this.baseUrl}${path}`, {
      method,
      headers: this.headers,
      body: body ? JSON.stringify(body) : undefined,
    });
    if (!res.ok) {
      const err = await res.json();
      throw new APIError(res.status, err.message);
    }
    return res.json() as T;
  }
}