Issue Diagnosis agent
Finds the root cause of a bug and proposes a fix.
The Issue Diagnosis agent is the lightweight sibling of the Spec agent, built for bugs. You describe what's going wrong; it reads your codebase read-only and writes a diagnosis — the root cause and a proposed fix. There's no spec and no task list, just the diagnosis.
Diagnosis reads your working copy, so the workspace needs a ready Foundation first. See Foundation.
What you share to start
Give the issue a title and describe the problem (up to 10,000 characters). You can attach screenshots or logs — up to 20 files, 10 MB each, the same limit that applies to files you add later when continuing a fix. Nothing is sent to Fragua while you compose; press Start diagnosis when you're ready. Unlike specs, issues don't use Knowledge Base documents, only your attachments.
How the turns work
The agent may ask a clarifying question or two on the page, or go straight to the diagnosis when your description is clear enough. It then writes the root cause and proposed fix and puts it in review.
You can send revision notes while it's in review and the agent reworks the diagnosis in the same session.
The ask-and-answer step repeats until the agent has enough to write the draft. After the draft, sending revision notes reopens the same conversation.
Accepting the result
Approve the diagnosis for a fix and the Execution agent builds it automatically, opening a pull request just like a spec. After a fix you can Start over from a fresh description.
Good to know
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While a run is going, only the person who started it can answer — everyone else in the workspace follows along read-only.
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If a run stalls or you change your mind, you can cancel it, then restart or resume from where it left off.
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Fragua lets you know when a draft is ready or a run fails, so you don't have to sit and watch it.
An approved fix is implemented automatically by the Execution agent.