Artifacts and workpieces
The files a run produces, the four editable workpiece kinds, uploads coming the other way, and the outbox that delivers follow-up work safely.
A run produces results a human can open. Some are static files; some are editable surfaces with revisions.
Artifact
A file or result produced by an agent and published with an authenticated preview or download link. Artifacts are first-class timeline items: the session view renders artifact cards after the answer text, and links are absolute.
Workpiece
A revisioned artifact editing surface with one of four canonical kinds:
Document
A DOCX-backed prose document.
Spreadsheet
An XLSX-backed grid.
Presentation
A PPTX-backed slide deck.
A PDF document.
Native renderers for these formats live in
packages/artifact-formats, and the
provider-neutral capability matrix lives in packages/artifact-workspace. Images
and videos remain previewable media artifacts, not workpieces.
Upload
A user-provided file accepted by the backend and attached to a run after validation. Uploads travel the other direction from artifacts: into a run rather than out of it. Inbound Slack images, for example, ride the run and render on the user’s turn in the timeline.
Outbox
Durable follow-up work written together with run state inside the finalization transaction, then processed safely after the transaction commits. The outbox pattern is how UseAgent does things like canonicalization and Slack delivery without a crash window: the intent is committed atomically with the run, and a worker delivers it afterward.