Cap transcription model fails to download

[asdrubalivan]

Description

When I try to download any transcription model in the captions tab of the cap editor, it fails

Reproduction

I go to the cap editor, press "Download recommended model" and the download fails.

When I try to do it again, it looks like the result is cached so I can't trigger the download again, it just instantly fails

Additional Context

• Cap version:Version 0.4.84 (0.4.84)
• Operating system, version: Mac OS Tahoe 26.4.1
• Device (optional):

The debug file is attached

logs.txt

[linear]

CAP-705

[tembo]

Some context from the codebase that may help investigate this:

The transcription model download logic lives in apps/desktop/src-tauri/src/captions.rs (the download_whisper_model command starting at line 1628 and download_parakeet_model at line 1838). The frontend handling is in apps/desktop/src/routes/editor/CaptionsTab.tsx (the downloadModel function around line 355).

Regarding the caching behavior you mentioned where retrying "instantly fails" - the frontend persists download state in localStorage under the key modelDownloadState (see lines 293-320 in CaptionsTab.tsx). If a download fails mid-progress, this state may not be properly cleared. A potential workaround while this is investigated would be to open the browser dev tools in the editor window (if accessible) and run localStorage.removeItem('modelDownloadState'), then try the download again.

The Parakeet model download was added relatively recently in PR #1705 and uses a staging directory pattern with atomic rename on completion. The model files are hosted on the CapSoftware/transcription-models GitHub releases.

The logs.txt attachment would be helpful to pinpoint whether the failure is:

• Network/timeout related (the HTTP client has a 30s default timeout per http_client.rs, though model downloads override this to 60 minutes)
• A path validation error (the validate_model_path function does canonicalization checks)
• A filesystem permission issue creating the model directory

One thing to note: macOS Tahoe 26.4.1 appears to be a beta/future version. If there are any filesystem permission changes in that OS version, they might affect the app's ability to write to its local data directory.