API Documentation – AI LRC Generator

Documentation – LRC Generator & Lyrics File Maker

API Documentation

Generate time-synced LRC lyric files from audio programmatically using the AI LRC Generator API.

Overview

The AI LRC Generator API lets you upload audio files and receive time-synced LRC lyrics asynchronously. The typical flow is:

Upload + trigger — POST /api/v2/open/audio_analysis (one-step, recommended)
Poll for result — GET /api/v2/open/audio_tasks/:id until status is COMPLETED

Base URL: https://ailrcgenerator.com

Authentication

All requests require an API key in the Authorization header.

Authorization: Bearer ailrc_sk_YOUR_KEY

Create and manage your API keys on the Developer API page. Keys are shown only once at creation — save them immediately.

Treat your API key like a password. Never expose it in client-side code or public repositories.

Rate Limits

The API is currently in public beta. Rate limits are set conservatively to prevent abuse and ensure service stability. We will gradually increase limits based on operational data and user feedback. If you have special requirements, please contact support.

Limits are applied per API key based on your account tier, using a three-layer sliding window (minute / hour / day). Hitting any layer returns 429.

Tier	Per Minute	Per Hour	Per Day
Free	3	20	50
Pro	10	60	300
Premium	20	200	1,000

Rate limit state is returned on every response:

X-RateLimit-Limit: 100
X-RateLimit-Remaining: 87
X-RateLimit-Reset: 1745024400

Exceeding the limit returns 429 Too Many Requests with a Retry-After header indicating how many seconds to wait.

Endpoints

Trigger Analysis

Upload an audio file and immediately start AI analysis (one-step mode).

POST /api/v2/open/audio_analysis
Content-Type: multipart/form-data

Request

Field	Type	Required	Notes
`file`	File	✓	mp3, wav, ogg, flac
`fileName`	string	—	Custom file name; falls back to original if omitted

Size limits by tier: Free 7 MB · Pro 20 MB · Premium 50 MB

Example

curl -X POST https://ailrcgenerator.com/api/v2/open/audio_analysis \
  -H "Authorization: Bearer ailrc_sk_YOUR_KEY" \
  -F "[email protected]" \
  -F "fileName=My Song"

Response

{
  "code": 0,
  "message": "ok",
  "items": {
    "taskId": "cm4abc123",
    "traceId": "cm4abc123",
    "status": "QUEUED",
    "queuePosition": 2,
    "remainingCredits": 46,
    "fileName": "song.mp3"
  }
}

Get Task Status

Fetch the current status and result of a task. Poll this endpoint until status is COMPLETED or FAILED. See Polling Guide for recommended intervals.

GET /api/v2/open/audio_tasks/:id

Example

curl https://ailrcgenerator.com/api/v2/open/audio_tasks/cm4abc123 \
  -H "Authorization: Bearer ailrc_sk_YOUR_KEY"

Response — in progress

{
  "code": 0,
  "items": { "taskId": "cm4abc123", "status": "PROCESSING", "fileName": "song.mp3" }
}

Response — completed

{
  "code": 0,
  "items": {
    "taskId": "cm4abc123",
    "status": "COMPLETED",
    "result": {
      "lrc": "[00:00.00]Line one\n[00:05.23]Line two\n[00:10.40]Line three"
    },
    "creditsUsed": 6,
    "completedAt": "2026-04-19T10:02:30Z",
    "fileName": "song.mp3"
  }
}

List Tasks

Return a paginated list of your audio tasks.

GET /api/v2/open/audio_tasks

Query parameters

Parameter	Default	Notes
`page`	`1`	Page number
`limit`	`20`	Max `100` per page
`status`	—	Filter: `PENDING` `QUEUED` `PROCESSING` `COMPLETED` `FAILED`

Example

curl "https://ailrcgenerator.com/api/v2/open/audio_tasks?page=1&limit=20&status=COMPLETED" \
  -H "Authorization: Bearer ailrc_sk_YOUR_KEY"

Delete Task

Delete a task and its associated data.

DELETE /api/v2/open/audio_tasks/:id

Tasks with status PROCESSING or QUEUED cannot be deleted.

Example

curl -X DELETE https://ailrcgenerator.com/api/v2/open/audio_tasks/cm4abc123 \
  -H "Authorization: Bearer ailrc_sk_YOUR_KEY"

Error Reference

All errors use a consistent envelope:

{
  "code": 403,
  "message": "Not enough credits",
  "businessCode": "not_enough_credits"
}

HTTP	`businessCode`	Meaning
`400`	—	Bad request — missing or invalid field
`401`	—	API key is missing, invalid, revoked, or expired
`403`	`not_enough_credits`	Insufficient credits
`403`	`level_not_enough`	File exceeds the size limit for your tier
`404`	—	Task not found or does not belong to your account
`429`	—	Rate limit exceeded — check `Retry-After`
`500`	—	Internal server error

Polling Guide

AI analysis is asynchronous and typically completes within 30–120 seconds depending on file length.

Recommended strategy: start at 3 s, back off to a 10 s cap, give up after 60 attempts (~10 min).

async function pollTask(taskId, apiKey) {
  let delay = 3000;
  for (let i = 0; i < 60; i++) {
    await new Promise(r => setTimeout(r, delay));
    const res = await fetch(
      `https://ailrcgenerator.com/api/v2/open/audio_tasks/${taskId}`,
      { headers: { Authorization: `Bearer ${apiKey}` } }
    );
    const { items } = await res.json();
    if (items.status === "COMPLETED") return items.result.lrc;
    if (items.status === "FAILED")    throw new Error(items.error ?? "Analysis failed");
    delay = Math.min(delay * 1.5, 10000);
  }
  throw new Error("Timed out");
}

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