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Version: Current

MCP server

Happo runs an MCP server that lets AI assistants help you manage your visual-regression comparisons. With it, assistants like Claude, ChatGPT, and Cursor can list comparisons for a commit, inspect diffs, and approve, reject, or report flake on your behalf.

The server uses the "Streamable HTTP" transport with OAuth 2.1 authentication, so connecting only requires a single URL. The endpoint is:

https://happo.io/api/mcp

Clients automatically discover the OAuth endpoints through /.well-known/oauth-protected-resource, so you don't need to configure tokens manually.

Available tools​

The MCP server exposes the following tools:

  • list_comparisons_for_sha — retrieves all comparisons linked to a specific commit SHA.
  • get_comparison_details — returns the complete diffs and snapshot information between two reports.
  • approve_comparison / reject_comparison — resolves a pending review after inspecting the differences.
  • report_flake — marks a spurious diff as a flake and records attribution.

Setup​

Claude Code​

Run the following command from your terminal:

claude mcp add --transport http happo https://happo.io/api/mcp

Authorization happens during the first tool use.

Claude Desktop​

Go to Settings → Connectors → "Add custom connector" and paste the MCP URL:

https://happo.io/api/mcp

Cursor​

Configure the server in ~/.cursor/mcp.json (global) or .cursor/mcp.json (project-specific):

{ "mcpServers": { "happo": { "url": "https://happo.io/api/mcp" } } }

Then reload Cursor or toggle the server under Settings → Features → Model Context Protocol.

Permissions​

Connected accounts inherit your permissions, and all actions are attributed to your user. You can revoke access at any time through the Connected applications section on the API tokens page.