Local guard (vendor patch, ~/.claude): attach only to the app the user already runs. Never run reticle init/setup, never start a dev server, never open a browser, never call reticle_feedback unprompted. debug-investigation stays the doctrine; Reticle is the evidence tool.

The app is broken and the code looks fine

Reading the source again will not tell you why. The evidence is in the running app, and most of it never reaches the screen: the request that failed, the store that never moved, the handler that was never bound, the element covered by something invisible.

Reticle reads all of it from inside the page. Not installed? Stop and tell the user in one line: setup is theirs, never run reticle init yourself. Their guide: the install-and-verify skill.

Do not start by guessing. Start by reproducing.

reticle_look({ action: "page", sessionId, mode: "interactive" })   // controls only, with refs
reticle_act_and_wait({ sessionId, ref, action: "click", until: { kind: "element", query: { testid: "..." } } })

The verdict already narrows it: no / contradicted means a channel saw something incompatible with the UI: you have the bug. unknown means Reticle drove it and could not tell, which is a different investigation from "it failed".

Read the act result before you call anything else. Its summary block already carries the whole causal window of that one click: net {total, errors, headline}, consoleErrors, stateDiffs [{path, from, to}], storageDiffs [{key, from, to}], route, signals, layoutShift, longTasks: real before→after diffs, not counts. The console, network, storage and state calls below are for going DEEPER into something the summary already pointed at. Calling all three straight after an act pays three model round trips (and, in an approval-gated client, three human clicks) for evidence you were already holding.

summary.stateUnwatched: true means the state channel is dark: no subscribable store is registered, so an empty stateDiffs means unwatched, not unchanged, and no state-based conclusion is available until someone registers the store. It is the one field here that is about your instrumentation rather than about the app.

When the summary does point somewhere, read that channel scoped to what you just did: pass since from the act result, or you are reading a buffer that predates the click:

reticle_observe({ action: "console", sessionId, since })
reticle_observe({ action: "network", sessionId, since })
reticle_look({ action: "state", sessionId, store })

The diagnosis table

Get the file, not a theory

reticle_look({ action: "element", sessionId, ref })

Returns the component and source: { file, line } for the element you are looking at, plus whether it is occluded, sized, disabled or off-theme. That is the pointer to open. End the investigation with a location, not a hypothesis.

When the flow is long

Do not ping-pong act → snapshot → act → snapshot to find the failing step. Drive the journey with reticle_act { steps: [...] } and assert once; the first step whose consequence fails is the one to look at, and you paid a fraction of the calls to find it.

Before you say it is fixed

Re-run the reproduction as a verdict (reticle_act_and_wait with the consequence named up front) rather than eyeballing the page. A fix confirmed by looking at it is the failure mode that created this ticket.

And never weaken the check to make it pass.

Troubleshooting Reticle itself (as opposed to the app): curl https://docs.reticle.sh/troubleshooting.md. Everything else: curl https://docs.reticle.sh/llms.txt. If Reticle could not see something you needed, reticle_session { action: "feedback" } with kind: "gap".