Developer integrations
regex101 provides HTTP APIs, an MCP server, editor links, and a separately licensed parser package.
| Your task | Use | Access |
|---|---|---|
| Read or save workspaces from code | Workspace API | Public reads and basic saves work without an account. Private saves require sign-in. |
| Work with regex101 from an AI client | MCP server | Account sign-in. Workspace tools are free; explanations require Pro. |
| Open the editor with supplied text | URL parameters | Free. The link opens an unsaved editor. |
| Render a text or structured explanation | Explain Regex API | Pro on regex101.com; an optional feature for self-hosted deployments. |
| Parse syntax inside your application | Regex Parser | Separate commercial package access and license. |
HTTP endpoints
Use https://regex101.com/api for REST requests and https://regex101.com/mcp for MCP connections.
The interactive API reference lists routes, request schemas, and responses. Its OpenAPI JSON supports client tooling.
Use your deployment's API reference for self-hosted integrations. Authentication, enabled features, and deployment limits can differ from regex101.com.
Pro features and self-hosted access
Saving multiple test strings or substitution pipelines requires Pro on regex101.com. Explain Regex API requests and MCP explanations also require Pro.
Self-hosted deployments use license features for MCP, explanations, multiple test strings, and pipelines. See Enterprise features.
Parsing and matching
The Explain Regex API returns explanations. The parser package returns syntax tokens inside your application. Neither runs a pattern against test text.
To execute matches, use a regex engine in your application. The workspace API stores editor data; it does not expose a remote matching endpoint.