Import audio (MP3) fails with Assembly AI 404 error

[hyper-charlie]

Description

User attempted to import their own MP3 audio file (~53.5 MB) via the "Import audio" feature. Assembly AI returned a 404 "not found" error.

Steps to Reproduce

1. Open Hyprnote
2. Select "Import audio"
3. Upload an MP3 file (tested with 53.5 MB file)
4. Observe Assembly AI error

Expected Behavior

Audio file should upload and begin transcription without errors.

Actual Behavior

Assembly AI returns: unexpectedStatus stats: 404

Reproducibility

Consistently reproducible — happens every time with this file.

Environment

• Platform: macOS (aarch64)
• OS Version: macOS 26.3.1
• App Version: 1.0.13
• Build: 3b53e1b
• Locale: de-DE

Additional Notes

• File format: MP3
• File size: 53.5 MB
• Error appears to be from Assembly AI API integration, possibly related to file upload or URL handling

[devin-ai-integration]

Investigation Findings

Root Cause: Missing /v2 path in AssemblyAI batch API URL

The 404 error occurs because the default baseUrl configured for AssemblyAI in the desktop settings (https://api.assemblyai.com) is missing the /v2 path prefix that AssemblyAI's batch API requires.

Detailed Flow

When a user clicks "Upload audio", the flow is:

1. File selection → options-menu.tsx calls fsSyncCommands.audioImport(sessionId, path) which copies the MP3 to the session directory as audio.ogg (via crates/fs-sync-core/src/audio.rs:import_to_session)
2. Batch transcription → The returned .ogg path is passed to runBatch (apps/desktop/src/stt/useRunBatch.ts)
3. Provider dispatch → crates/listener2-core/src/batch/mod.rs:run_batch_simple creates a BatchClient<AssemblyAIAdapter> using conn.baseUrl from useSTTConnection
4. Upload to AssemblyAI → crates/owhisper-client/src/adapter/assemblyai/batch.rs:do_transcribe_file calls batch_api_url(api_base) then appends /upload

The Bug

In crates/owhisper-client/src/adapter/assemblyai/mod.rs:78-91, batch_api_url():

pub(crate) fn batch_api_url(api_base: &str) -> url::Url {
    if api_base.is_empty() {
        return Provider::AssemblyAI.default_api_url() // "https://api.assemblyai.com/v2"
            .unwrap().parse().expect("invalid_default_api_url");
    }
    let url: url::Url = api_base.parse().expect("invalid_api_base");
    url // Returns as-is, WITHOUT /v2
}

• When api_base is empty → falls back to https://api.assemblyai.com/v2 ✓
• When api_base is non-empty (which it always is from the UI) → returns it as-is ✗

The default baseUrl in apps/desktop/src/settings/ai/stt/shared.tsx:137 is:

baseUrl: "https://api.assemblyai.com",  // missing /v2

So the upload URL becomes https://api.assemblyai.com/upload instead of https://api.assemblyai.com/v2/upload, resulting in a 404.

Compare with the streaming side: streaming_ws_url() (same file, line 42-76) properly handles the non-empty case by appending the correct path (/v3/ws) via append_path_if_missing. The batch side doesn't do this.

Relevant Files

File	Role
apps/desktop/src/settings/ai/stt/shared.tsx:137	Default baseUrl for AssemblyAI (https://api.assemblyai.com)
crates/owhisper-client/src/adapter/assemblyai/mod.rs:78-91	batch_api_url() — doesn't append /v2 for non-empty base
crates/owhisper-client/src/adapter/assemblyai/batch.rs:119-153	do_transcribe_file() — appends /upload and /transcript to the base URL
crates/owhisper-client/src/adapter/http.rs:7-15	ensure_success() — returns Error::UnexpectedStatus { status: 404, body }
apps/desktop/src/session/components/floating/options-menu.tsx:175-216	Upload audio trigger flow
apps/desktop/src/stt/useRunBatch.ts	Batch orchestration
crates/listener2-core/src/batch/mod.rs:156-158	Routes to run_batch_simple<AssemblyAIAdapter>

Suggested Fix

Option A (recommended): Fix batch_api_url() to append /v2 when the URL points to AssemblyAI, similar to how streaming_ws_url() handles it:

pub(crate) fn batch_api_url(api_base: &str) -> url::Url {
    if api_base.is_empty() {
        return Provider::AssemblyAI.default_api_url()...;
    }
    let mut url: url::Url = api_base.parse().expect("invalid_api_base");
    append_path_if_missing(&mut url, "v2");
    url
}

Option B: Change the default baseUrl in shared.tsx to include /v2:

baseUrl: "https://api.assemblyai.com/v2",

This fixes new installs but not existing users who already saved the base URL without /v2.

Ideally both changes should be applied.