REST Client

Enables developers to write HTTP requests as plain text in .http or .rest files with RFC 2616-compliant syntax (method, headers, body), then execute them directly via CodeLens 'Send Request' links without leaving the editor. Requests are stored as version-controllable text files rather than binary formats, and multiple requests per file are delimited by ### separators, allowing request organization and history within a single document.

Supports variable substitution in request URLs, headers, and bodies using {{variableName}} syntax with four scope levels: environment, file, request, and prompt. Includes built-in system variables ({{$guid}}, {{$timestamp}}, {{$randomInt}}, {{$datetime}}, {{$processEnv}}, {{$dotenv}}, {{$aadToken}}) that generate or retrieve values at request time, plus custom variables defined in environment files or inline within .http files. Variables are resolved before request execution, enabling dynamic test data generation and credential injection.

Organizes requests into named environments (dev, staging, production, etc.) with environment-specific variables and settings. Variables can be scoped to environment level (shared across all requests in that environment), file level (shared across requests in a single .http file), request level (specific to one request), or prompt level (entered at request time). Environments are defined in VS Code settings and can be switched via command palette or settings UI.

Enables requests to reference values from previous request responses using variable syntax. Developers can extract specific fields from JSON/XML responses and store them as variables for use in subsequent requests. This enables multi-step workflows (e.g., login → get token → use token in authenticated request) without manual copy-paste. The extraction mechanism and syntax are not fully documented.

Supports HTTP/HTTPS proxy configuration for routing requests through corporate proxies or VPNs. Proxy settings are configured in VS Code settings, and the extension automatically routes all HTTP requests through the specified proxy. Proxy authentication mechanism is not documented.

Supports six authentication mechanisms: Basic Auth (username:password in Authorization header), Digest Auth (RFC 2617 challenge-response), SSL Client Certificates (mutual TLS), Azure Active Directory (AAD token generation via {{$aadToken}} variable), Microsoft Identity Platform, and AWS Signature v4 (request signing). Authentication credentials are configured per request or environment, and the extension handles credential injection and protocol-specific header/signature generation before sending the request.

Displays HTTP responses in a dedicated syntax-highlighted pane with four preview modes: headers only, body only, full response (headers + body), and request+response combined. Responses are automatically formatted (JSON and XML indentation applied), and developers can export raw response bodies or full responses to disk files. Image responses are rendered as previews rather than raw binary. Font rendering (size, family, weight) is customizable for readability.

Automatically saves request execution history and persists cookies across multiple requests within a session. History is accessible via a dedicated history view (mechanism unknown), and developers can rerun previous requests without re-entering them. Cookies received in Set-Cookie headers are stored and automatically included in subsequent requests to the same domain, enabling stateful API testing (e.g., login flows, session-based APIs).

Enables developers to write GraphQL queries and mutations in .http/.rest files with full variable support ({{variableName}} syntax). Queries are executed against GraphQL endpoints, and responses are returned with syntax highlighting. The extension handles GraphQL-specific request formatting (Content-Type: application/json, query/variables in request body) automatically.

Allows developers to paste cURL commands directly into .http/.rest files or convert existing requests to cURL format for sharing. The extension parses cURL syntax (method, headers, body, authentication) and executes the request, or generates equivalent cURL output from a defined request. This enables interoperability with cURL-based workflows and documentation.

Provides code snippets and templates for constructing SOAP request envelopes with proper XML structure (soap:Envelope, soap:Body, soap:Header). Developers can insert SOAP envelope templates and customize them with service-specific operations and parameters. The extension handles SOAP-specific headers (Content-Type: text/xml, SOAPAction) automatically.

Generates equivalent HTTP request code in multiple programming languages (Python, JavaScript confirmed; full list unknown) from a defined request. Developers can copy generated code snippets and paste them directly into their applications. The extension handles language-specific HTTP libraries (requests, fetch, axios, etc.) and generates idiomatic code for each language.

Provides VS Code language support for .http and .rest file types with syntax highlighting for HTTP methods, headers, URLs, and request bodies. Includes IDE features: line comments (# or //), auto-closing brackets, code snippets for GET/POST operations, symbol navigation for request and file-level custom variables, and CodeLens support for inline 'Send Request' buttons. Markdown code blocks with http/rest language tags are also syntax-highlighted.