Review and revision

Review an agent edit in the editor before treating the design as finished. Fanta provides canvas screenshots, layer inspection, an undoable edit history, and project source files for this loop.

Review a canvas edit

Ask the agent to capture a screenshot after applying an edit. Check the target frame at its intended size: alignment, text overflow, clipping, spacing, contrast, image crop, and visual hierarchy. Use batch_get to inspect precise properties when a screenshot is ambiguous. Give the next revision as a short list of observable changes.

A batch_design edit paints each operation as a temporary preview, then commits the batch as one undo transaction. If an operation fails or the batch is canceled, the preview rolls back and the result identifies the failing operation. If a completed batch is wrong, undo it in Fanta or request a corrective batch. Work with exact node IDs obtained from the current document.

Review source changes

Pages and component masters are stored as FNX files with companion JSON headers. Read FNX through read_fnx_source or normal file tools; inspect managed JSON with file tools. The MCP reader slices by 1-based line offset, so follow its next_offset before replacing a file. Check a complete FNX or managed JSON candidate with validate_fnx_source before writing. Existing files are checked against the full project, including types and references. External edits to an open project are picked up by the editor after a short delay. A source parse error leaves the last valid canvas state visible while you fix the file. See FNX source.

Source files are useful for Git review. Check the actual canvas too: a clean textual diff alone does not establish that the rendered design is correct.

Check the reverse as well: a visible canvas edit does not prove the source saved. Fanta retains authored FNX comments and extra attributes during structural saves when it can. If deletion or a node-type change would lose a source-only attribute that Undo cannot restore, it reports a preservation error. Undo the canvas edit or make an intentional source edit and validate it, then verify both canvas and diff again.

Comments and handoff

Fanta's canvas comments can attach pins to design positions and hold replies, mentions, attachments, and resolved state. They are stored as project page metadata. External agents can call list_comments for unresolved threads on the active page, or include resolved threads and choose a page. Use reply_comment with the exact thread ID to answer, and set resolve: true only after the request has been verified. The in-app agent's related tool is design_comments. Comments do not appear in PNG, JPG, SVG, or PDF exports.

When the design is ready, export the selected layers or active page from the editor. For another editable copy, keep the native project directory or use a supported snapshot workflow. See formats and interoperability.