Happo MCP
An official MCP server provided by Happo that enables AI agents to manage visual regression and accessibility testing. It allows agents to list comparisons for commits, inspect detailed diffs including accessibility violations, accept or reject changes, and report flakes, facilitating automated code review workflows without requiring repository access.
Endpoint and access
OAuth sign-in: the first time you connect, your client opens the vendor's own authorization prompt in a browser.
https://happo.io/api/mcpChecks and signals
Each line is separate evidence, not a trust score.
- Passed Endpoint answered the live check ·
- Passed Official MCP Registry namespace is tied to happo.io ·
- Passed Endpoint is on the registry namespace domain ·
- Availability 1 of 1 checks passed in 30 days
What you can do with it
- List visual comparisons for a specific commit SHA
- Inspect detailed diffs and accessibility violations
- Accept or reject visual changes automatically
- Report spurious diffs as flakes
Source and maintenance
Tools
Reported by the attributed source; not independently observed by Koskamo.
90-day uptime
A lightweight connection check about every six hours, sampled on hosts with many listings. It shows the server answered, not that its tools work.
- 2026-11-07: 1 of 1 checks answered
30-day availability
Aggregated from read-only remote checks; this is not a tool-execution or security guarantee.
- Successful checks
- 1 of 1 (100%)
- Average latency
- 69 ms
- 95th percentile latency
- 69 ms
Maintenance history
Public check and source-refresh events. Editorial and ownership records remain private.
- · probe · passed · 69 ms · metadata changed · refuses unauthenticated initialize (HTTP 401)
Connect from your client
Each snippet registers the same endpoint; pick the client you use.
Claude Code
claude mcp add --transport http happo-mcp https://happo.io/api/mcpCodex
codex mcp add happo-mcp --url https://happo.io/api/mcpCursor
{
"mcpServers": {
"happo-mcp": {
"url": "https://happo.io/api/mcp"
}
}
}Cline
{
"mcpServers": {
"happo-mcp": {
"type": "streamableHttp",
"url": "https://happo.io/api/mcp",
"disabled": false
}
}
}VS Code
{
"servers": {
"happo-mcp": {
"type": "http",
"url": "https://happo.io/api/mcp"
}
}
}Gemini CLI
gemini mcp add --transport http happo-mcp https://happo.io/api/mcpClaude Desktop
https://happo.io/api/mcpWindsurf
{
"mcpServers": {
"happo-mcp": {
"serverUrl": "https://happo.io/api/mcp"
}
}
}Let your agent find its tools
Find servers like Happo MCP from your agent. Add Koskamo once to search the index for endpoints, access requirements, and client setup. Public discovery needs no key.
Other developer tools servers
Do you run Happo MCP?
Prove ownership with a DNS record, a well-known file, or your Official MCP Registry entry, and your edits publish immediately. Proofs are re-checked weekly; admins can still hide or remove a listing.