The Reticle bridge + MCP server. It hosts a localhost WebSocket endpoint your app's @reticlehq/browser SDK connects to, and exposes MCP tools your coding agent uses to look at, act on, observe, and assert against the live app.

npx @reticlehq/server init   # wire the project: SDK + build plugin + MCP registration
npx @reticlehq/server mcp    # MCP over stdio; auto-starts the bridge on ws://localhost:4400

The package installs a reticle bin, so inside a project reticle mcp and npx @reticlehq/server mcp are the same command. reticle is not a package name on npm.

Point your agent at it. On Claude Code, register it at user scope:

claude mcp add reticle -s user -- npx @reticlehq/server mcp

Default tools (18):

reticle_sessions, reticle_snapshot, reticle_query, reticle_inspect, reticle_navigate, reticle_act, reticle_act_sequence, reticle_act_and_wait, reticle_observe, reticle_wait_for, reticle_assert, reticle_network, reticle_console, reticle_state, reticle_feedback, reticle_session, reticle_tools, reticle_run.

Only reticle_act_and_wait and reticle_assert return a verdict; everything else moves or reads the app.

Another 30 tools ship but are not advertised, to keep the per-turn tool payload small: screenshots and visual diff, saved flows, recording, baselines, clock control, viewport, crawl, coverage, network mocking, leases and more. Reach any of them by name with reticle_run, list them with reticle_tools, or advertise the whole surface with RETICLE_ADVERTISE_ALL_TOOLS=1 (this roughly doubles the per-turn tool payload).

See the main README.

License

FSL-1.1-ALv2 (source-available: free for any use except reselling Reticle itself; converts to Apache-2.0 after two years). Files under dist/ee/ are enterprise features covered by the Reticle Enterprise License — free for development, testing, and evaluation; a license key activates them in production.