Symptom
-------
Loading a workflow from the Kforge Labs sidebar whose name matched an
existing native ComfyUI workflow file (e.g. user has both
`user/default/workflows/Hi-Res-FIX_v01.json` AND a Koolook entry
named `Hi-Res-FIX_v01`) and then clicking ComfyUI's native save
button produced a confusing toast:
Error storing user data file 'workflows/Hi-Res-FIX_v01.json':
409 Conflict
The user's only workaround was to rename via Save As.
Root cause
----------
ComfyUI's frontend save flow at
`Comfy-Org/ComfyUI_frontend/src/stores/userFileStore.ts`:
const resp = await api.storeUserData(this.path, this.content, {
overwrite: this.isPersisted,
...
})
`overwrite: this.isPersisted` — passes `overwrite=true` only when
ComfyUI considers the workflow already persisted to disk. Workflows
loaded via the 4th-arg trick on `loadGraphData(..., wfName, {})`
become temporary workflows (`isPersisted = false`), so save POSTs
with `overwrite=false`. The server (correctly) 409s because a real
file already exists at `workflows/<wfName>.json`.
The 409 is **correct ComfyUI behavior** — protecting the user from
overwriting an unrelated file with the same name. ComfyUI's frontend
has no public API for extensions to mark a workflow as
"persisted-from-elsewhere," so we can't make their save flow use
overwrite=true for our loaded workflows.
Fix
---
`loadWorkflowOntoCanvas` now HEADs
`/userdata/workflows/<wfName>.json` before calling `loadGraphData`.
- No collision → tab name is the bare `<wfName>` (existing behavior).
- Collision → tab name becomes `<wfName> (Koolook)`. Save-back
writes `workflows/<wfName> (Koolook).json`, which is a clean
new artifact that doesn't collide with the user's native file.
The load toast surfaces the renaming when it happens, so the user
knows their tab was suffixed and why. When the deployment doesn't
support HEAD (rare), the catch falls through to the bare name —
worst case is the same 409 the user already knows how to work
around.
Verification
------------
- `node --input-type=module --check` on `canvas_io.js` — clean.
- `python tools/preflight_release.py --skip manager-meta -v` PASS.
- Synced to live install on Mac via `scripts/sync_to_dev.py` for
smoke-test against an actual ComfyUI session.
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
