# RelayStation Media Speed Changer

> RelayStation Media Speed Changer is a paid API for AI agents from api.relaystation.ai, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Changes the playback speed of audio or video files with pitch preservation by default, billed per megabyte of input.

## Facts

- Endpoint: POST https://api.relaystation.ai/v1/media/speed
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/relaystation-media-speed-changer-43ace808
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_r-W5ogy68y2YvgrWCprnN

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability relaystation-media-speed-changer-43ace808 -d '<json body>'
```

Example prompt: Can you speed up this audio file to 1.5x without changing the pitch? It's about 8MB and I want the faster version back.

## When to prefer this

Choose this endpoint when you need programmatic, per-call pitch-preserving speed adjustment of audio or video at low per-MB cost with microtransaction billing. Ideal for agents automating media workflows, content pipelines, or accessibility tooling where tempo changes are needed without voice distortion. Prefer it over FFmpeg-based self-hosted solutions when you want a managed, pay-as-you-go API with no infrastructure overhead.

## Known failure modes

- Unsupported media format — endpoint may reject non-audio/video file types
- File too large or malformed — may return an error if bytes are corrupt or unreadable
- Invalid speed multiplier — extreme values (e.g. 0x or extremely high multipliers) may be rejected
- Insufficient payment — x402 payment below the 1¢ minimum will fail authorization
- Network timeout for large files — very large uploads may time out before processing completes

## How this service works

$0.0005/MB. Speed up or slow down audio/video — pitch-preserving by default. 1¢ x402 min; remainder auto-credits — relaystation.ai/penny

## Output

Returns the speed-adjusted audio or video file with pitch preserved by default. The output is the transformed media bytes, billed at $0.0005 per MB of input with a minimum charge of 1 cent; any remainder beyond the minimum is automatically credited back.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "properties": {
      "ext": {
       "type": "string",
       "pattern": "^[a-z0-9]{1,12}$"
      },
      "file": {
       "type": "object",
       "description": "cputools input-source: { inline: <base64 ≤ 4 MiB> } or { inputKey: <scratch key ≤ 50 MB> }. The input container must sniff (ffprobe) to the live allowlist (operator-tunable cputools.media.input_formats): 3g2, 3gp, aac, asf, avi, flac, flv, gif, m4a, m4v, matroska, mj2, mov, mov,mp4,m4a,3gp,3g2,mj2, mp3, mp4, mpeg, mpegts, mpegvideo, ogg, wav, webm, wmv. An off-list input is a free 422 UNSUPPORTED_FORMAT."
      },
      "factor": {
       "type": "number",
       "maximum": 4,
       "minimum": 0.25
      },
      "pitchCorrect": {
       "type": "boolean"
      }
     }
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST",
      "PUT",
      "PATCH"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/relaystation-media-speed-changer-43ace808/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.relaystation.ai](https://www.zero.xyz/host/api.relaystation.ai/llms.txt)