ApiClient - REST & cURL Tester

ApiClient is a mobile REST API client and HTTP client for developers. Test, debug and manage REST, GraphQL and WebSocket APIs anytime, anywhere, directly on your Android device. No need to open your laptop just to test an API endpoint, inspect SSE event streams, test FCM push notifications, or generate code snippets. ApiClient is a lightweight API tester that gives you desktop-grade API testing power on mobile. Import collections and OpenAPI specs, send requests with custom headers, Bearer tokens and JSON bodies, and inspect every response. KEY FEATURES 1. Multi-Protocol API Testing • REST Client: GET, POST, PUT, DELETE, PATCH, HEAD and OPTIONS. • GraphQL Suite: Dedicated Query and Variables editor with syntax formatting and error handling. • Real-Time WebSockets: Connect to ws:// and wss:// endpoints with live frame logging, custom headers and a message composer. • Live SSE Streaming: Inspect Server-Sent Events in real time for AI and LLM streaming APIs. 2. Import Collections & OpenAPI • Collection import: Supports collection formats v1, v2.0 and v2.1 with multi-level nested folders. • OpenAPI / Swagger: Import OpenAPI 2.0 and 3.0 specifications in both JSON and YAML. • 1-Click cURL: Instant cURL import from clipboard and export to cURL. 3. 9-Language Code Generator Convert API requests into clean, ready-to-run code snippets: • Python (requests) • JavaScript (fetch) • Kotlin (OkHttp) • Swift (URLSession) • Dart / Flutter (http) • Go (net/http) • PHP (cURL) • Java (OkHttp) • cURL command 4. Push Notification Tester (FCM HTTP v1) • FCM HTTP v1 support with on-device OAuth2 token generation. • Import a Service Account JSON or use Bearer tokens. • Custom notification payloads and topic messaging. 5. Session Cookie Manager & Variables • Automatic cookie jar captures Set-Cookie response headers. • Domain-grouped cookie inspector with add, edit and clear. • Dynamic variables: use {{variable}} substitution across URLs, headers and request bodies. 6. Developer Power Tools • AI Response Diagnostics: Instant offline root-cause troubleshooting for HTTP errors. • JSON Formatter: Beautify and minify JSON with syntax highlighting. • Crypto Suite: Base64 and AES 128/256 encryption and decryption utilities. • History & Collections: Auto-saved request history with search, export and quick replay. 7. Modern UI & Dark Theme • Full Dark and Light theme with automatic system sync. • Clean, responsive interface optimized for all screen sizes. 8. LOCAL-FIRST & PRIVATE Your API keys, tokens, requests and cookies are stored on your device. No account or sign-up is needed, and your requests are sent only to the servers you choose. Perfect for developers, QA testers and anyone who needs a fast API tester, REST API client or cURL tool on the go.