audioproxy
Audio variants, addressed by URL
FreeVoice4,706 impressions#3 of its week
Audioproxy renders audio variants on demand via signed URLs, streaming and caching them without a job queue.
- for
- Developers needing on-the-fly audio transcoding and variant generation.
- pricing
- open source
- license
- Apache-2.0
Key features
- URL-based API — All variant options are encoded in the URL, which also serves as the cache key.
- Streaming render — The first request streams encoded audio while it is being generated.
- Cache & range support — Subsequent requests hit a cached file with full range-request capability.
- S3 or directory source — Reads source files from a mounted directory or any S3-compatible bucket.
- Audio processing options — Supports format, bitrate, VBR, resample, trim, fade, gain, loudness normalization and speech enhancement.
- Peak data format — Can output waveform min/max pairs as JSON or binary for UI rendering.
- Health & metrics — Provides /health, /ready and Prometheus metrics endpoints.
- Signed URLs — Requests are signed GETs; signatures are excluded from the cache key for shared variants.
Use cases
- Generate low-bitrate preview clips for large audio files on demand.
- Serve different audio formats (mp3, opus, aac, wav) without pre-transcoding.
- Provide waveform data for custom audio players.
- Deliver range-capable audio streams after the first request is cached.
- Integrate with Rails ActiveStorage to produce signed variant URLs.
audioproxy vs alternatives
 audioproxy |  Voice Calling SDK by Dyte |  Layercode CLI |  Chord Mini |  Free AI Text to Speech by Leap AI | |
|---|---|---|---|---|---|
| Best for | On-demand audio variant rendering | Voice call integration | Voice AI agent creation | Audio analysis | AI text-to-speech |
| Pricing | Open source | Subscription | Subscription | Free | Free |
| DevHunt upvotes | 12 | 44 | 13 | 5 | 5 |
| Launched | Sep 2026 | May 2024 | Oct 2025 | Aug 2025 | Sep 2024 |
- audioproxy vs Voice Calling SDK by Dyte: Provides a real-time voice calling SDK, not on-demand audio transcoding.
- audioproxy vs Layercode CLI: CLI for building voice AI agents, focuses on AI rather than raw audio variant rendering.
- audioproxy vs Chord Mini: Open-source chord and beat detection tool, unrelated to variant generation.
- audioproxy vs Free AI Text to Speech by Leap AI: Text-to-speech service that generates audio from text, not transform existing files.
audioproxy FAQ
How does Audioproxy avoid storing state?+
All variant options are part of the URL, which doubles as the cache key, so no server-side state or configuration is needed.
What happens on the first request for a variant?+
The proxy streams the audio while encoding it and writes the result to the cache; concurrent requests coalesce onto the same render.
Can I use Audioproxy with existing S3 buckets?+
Yes, point the container at any S3-compatible bucket or a local read-only directory as the source.
How are signed URLs validated?+
Requests must include a signed GET token; the signature is not part of the cache key, allowing shared caching of identical variants.
What formats and processing options are supported?+
Formats include mp3, opus, ogg, aac, m4a, flac, wav, and peaks; options cover bitrate, VBR quality, resample, channels, bit depth, trim, fade, gain, loudness normalization and speech enhancement.
Is there a health check for the service?+
Yes, /health always returns 200 and /ready returns 503 when queue depth exceeds a threshold; metrics are exposed via /metrics.
Summarized by DevHunt from audioproxy.dev · Sep 27, 2026. Details may change; check the official site.
