forwardemail/superagent
Superagent
Superagent is an isomorphic JavaScript HTTP client for sending network requests and processing responses across both Node.js and web browser environments. It provides a fluent request builder that uses a chainable interface to construct complex network requests with custom headers, query strings, and bodies.
The library functions as a runtime-agnostic request adapter, allowing a single codebase to work consistently across different environments. It includes specialized capabilities such as an HTTP/2 client for forcing the HTTP/2 protocol and a Node.js agent for managing Unix socket connections and TLS settings.
Its capability surface covers API integration and data consumption, including multipart file uploads, automatic response deserialization, and stream-based data piping. It also provides security and session management through persistent cookie state, request authentication, and TLS connection configuration.
The system is extensible via a client plugin system and plugin-based lifecycle hooks that allow for custom behavior during the request cycle.
Features
- Fluent Interfaces - Implements a fluent interface for constructing and sending network requests through chainable method calls.
- HTTP Request Clients - Provides a comprehensive tool for executing standard HTTP methods to interact with remote servers and APIs.
- Data Fetching and API - Facilitates fetching and parsing JSON or binary data from external APIs for use in applications.
- Automatic Body Deserializers - Automatically converts response data from formats like JSON or URL-encoded forms into usable objects.
- Runtime Adapters - Provides a runtime adapter layer that enables the same request code to work across both browser and Node.js environments.
- HTTP Request Builders - Utilizes a builder pattern to construct HTTP requests using a chain of method calls.
- Isomorphic HTTP Clients - Maintains a single, consistent API for making asynchronous requests across both browser and Node.js runtimes.
- Request Header Configuration - Allows assignment of specific field names and values to HTTP headers to control request metadata.
- HTTP Error Handling - Provides capabilities to interpret specific HTTP status codes as errors and define custom success criteria.
- Content-Type Based Deserializers - Detects the Content-Type header of incoming responses to automatically parse bodies into appropriate formats.
- Request Body Handling - Automatically serializes data as JSON, URL-encoded forms, or FormData for transmission.
- HTTP Stream Piping - Supports piping readable and writable streams directly to request and response bodies for efficient handling of large payloads.
- Request Retries - Automatically re-attempts failed network requests based on specific criteria to handle transient failures.
- HTTP/2 Protocol Implementations - Includes a specialized client capable of forcing the HTTP/2 protocol for high-performance communication.
- HTTP/2 Support - Supports initiating network requests using the HTTP/2 protocol with the ability to prevent protocol fallback.
- HTTP Request Piping - Enables streaming data directly from a source into a request or piping a response body to a destination.
- Node.js HTTP Agents - Ships a Node.js agent for managing TLS settings, Unix socket connections, and persistent session cookies.
- Specialized Network Transports - Enables specialized communication via Unix domain sockets and enforced HTTP/2 protocol usage.
- HTTP Authentication Schemes - Supports applying basic and bearer token authentication to outgoing requests using native browser and Node.js methods.
- Secure Connection Handlers - Manages secure connections by specifying TLS certificates, keys, and validation settings.
- Session & Cookie Handlers - Maintains a persistent cookie jar to simulate browser-like sessions in non-browser environments.
- Lifecycle Plugin Systems - Implements a plugin architecture with lifecycle hooks to extend request behavior for caching, throttling, and signing.
- Multipart Upload Utilities - Constructs complex multipart requests containing both file attachments and text fields for data uploads.
- Request Lifecycle Hooks - Extends request behavior by executing a sequence of plugin-based middleware functions during the request cycle.
