The error state has never run

Every app has a catch block nobody has executed and an empty state nobody has seen. They are written from imagination, shipped untested, and discovered by a user on a bad day.

Reticle can force those conditions in the running app. Not installed? RETICLE_INSTALL_SOURCE=npx_skill npx @reticlehq/server@latest init, then the install-and-verify skill.

Read this before you start: network mocking needs a driven or leased browser

reticle_network_mock intercepts requests in a browser Reticle owns, and the always-on SDK cannot do it. A connected tab with neither reticle drive nor a lease still returns { ok: false, reason: "no-cdp-provider" }.

Your route is a leased Playwright tab (reticle_lease acquire) or RETICLE_CDP_URL pointed at a Chrome started with remote debugging:

# macOS — the user runs this once, in their own Chrome
/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --remote-debugging-port=9222

RETICLE_CDP_URL=http://localhost:9222 npx @reticlehq/server@latest mcp