# Fusee

> Fusee is self-hosted, Sentry-compatible error and CI-failure tracking
> (Go + Dolt). You are reading the live agent instructions for the backend at
> https://fusee.work. Fusee's primary interface for a coding agent is an MCP server:
> your agent lists the bugs Fusee captured, reads the stack trace and
> diagnostic context, fixes the code in your editor, and marks the issue
> resolved — your repo never crosses the network.

## Which instance you are on

This document came from https://fusee.work, and that is the only backend it describes.
Every URL below is absolute against it on purpose.

fusee.work and faultline.live are SEPARATE INSTANCES of Fusee — the same code,
but a database, an account list and a project list each, with no data moving
between them:

- fusee.work — the current hosted instance. Use it for a new setup.
- faultline.live — the original hosted instance, still running unchanged. Use
  it if the user already has an account, projects or DSNs there. There is no
  migration.
- a self-hosted instance (localhost or the operator's own domain) — same
  token model and JSON API as both of the above.

An account or token minted on one instance is rejected by the others, and a
DSN names the instance that issued it. Do not mix hosts: read the host out of
the user's own DSN, or out of this document's URLs, and stay on it.

## Wire your agent into this backend (https://fusee.work)

The MCP server is this backend's endpoint, served over MCP Streamable HTTP.
There is nothing to install:

    https://fusee.work/mcp

1. Mint an API token (it starts with "fl_"):

       https://fusee.work/dashboard/account/tokens

2. Register the endpoint with your client, passing the token as a header.
   Claude Code:

       claude mcp add --transport http fusee https://fusee.work/mcp \
         --header "Authorization: Bearer fl_..."

   Cursor, Windsurf and other clients that read mcp.json:

       {
         "mcpServers": {
           "fusee": {
             "url": "https://fusee.work/mcp",
             "headers": { "Authorization": "Bearer fl_..." }
           }
         }
       }

Clients that add a connector by URL (the Claude mobile, web and desktop
apps: Settings -> Connectors -> Add custom connector) can skip the token on
the hosted service: they discover the OAuth flow from the 401 and walk the
user through signing in and approving. The grant is an fl_ token listed (and
revocable) at https://fusee.work/dashboard/account/tokens.

## Tools your agent gets

- list_issues        — open bugs for the current project
- get_issue          — full detail on one bug (root cause, fix metadata)
- get_issue_context  — stack trace + breadcrumbs + device/OS + last event
- list_events        — recent events for an issue (useful for flaky bugs)
- mark_resolved      — close a bug with root cause + fix explanation + commit SHA
- snooze             — defer a bug until a date, with a reason
- capture_learning   — record a forward-looking lesson (pattern + prevention) so each fix makes future triage smarter
- list_learnings     — list this project's captured learnings; check them when triaging a new issue
- select_project     — list projects and pick the active one

The first tool response prints a one-line banner naming the backend and the
resolved project, so you know immediately where you are pointed.

## Which project am I working in?

Append ?project_id=N to the endpoint URL to pin a project. Otherwise a token
that sees exactly one project uses it, and select_project picks among several.
A repo tracked on more than one backend has a different id on each.

## Talk to the JSON API directly (no MCP)

Same data, REST shape, Bearer-token auth (Authorization: Bearer fl_...):

    GET   https://fusee.work/api/{project_id}/issues/
    GET   https://fusee.work/api/{project_id}/issues/{issue_id}/
    GET   https://fusee.work/api/{project_id}/issues/{issue_id}/context/
    GET   https://fusee.work/api/{project_id}/issues/{issue_id}/events/
    PATCH https://fusee.work/api/{project_id}/issues/{issue_id}/          (resolve)
    POST  https://fusee.work/api/{project_id}/issues/{issue_id}/snooze/

## More

- https://fusee.work/mcp — human-facing page: what the endpoint is and how to connect
- https://github.com/outdoorsea/faultline — source