Audio trim

POST /api/audio-trim1 quota unit per call · cache hits free

Trim a WAV file online or via API: cut [start, end) seconds out of the audio without re-encoding — PCM samples are copied bit-exact.

Cuts a [start, end) window out of a WAV file. Lossless — the PCM (or float) sample bytes inside the window are copied verbatim under a fresh canonical header, never re-encoded. - `startSeconds` — where the cut begins (default 0). - `endSeconds` — where it ends; omit to keep everything after the start point. The window is snapped to whole sample frames. For compressed formats convert to WAV first, or use wav-to-mp3 on the result to re-compress.

Inputs

Name	Type	Default	Description
audio*	file	—	WAV file (PCM or IEEE float).
startSeconds	number (0…86400)	0	Window start, in seconds from the beginning.
endSeconds	number (0…86400)	—	Window end, in seconds. Omit to keep through to the end of the file.

Response

Modes: binary, stream, json. Cache: yes (24h TTL).

Large outputs stream: responses over the 4 MiB cache limit are piped through as they are produced instead of buffered. They carry x-cache-skip: size and are never cached — identical follow-up calls recompute.

Every response carries x-cache (HIT / MISS / BYPASS), x-cache-signature (stable across identical inputs), and the rate-limit headers listed below.

Quota & limits

Cost per call	1 unit against the 10,000-unit monthly quota. Cache hits are free — only cache misses decrement.
Burst limit	200 requests per rolling minute, shared across all tools.
Max request size	`100 MiB` (base64 inflates file payloads ~33% — the limit applies to the decoded bytes).
Max response size	`100 MiB`
Timeout	30s wall clock.
Rate-limit headers	`X-RateLimit-Limit`, `X-RateLimit-Remaining`, `X-RateLimit-Burst-Limit` on every response; `X-Quota-Warning` once 80% of the monthly quota is spent; `Retry-After` on 429s.

Errors

Errors are JSON with an error string; schema failures add a details object (Zod's flattened field errors).

Status	When	Body
400	Input fails the tool's schema (wrong type, missing required field, malformed base64) or the file bytes can't be parsed as the expected format.	{ "error": "invalid inputs", "details": { "fieldErrors": { … } } }
401	Missing or invalid X-Api-Key / X-Account-Id headers (or no session when called from the browser).	{ "error": "unauthorized" }
404	Unknown tool id, or calling /api/* on the website hostname instead of api.xtract.bot.	{ "error": "not found" }
413	Request body over the tool's max request size, or an image header declaring more megapixels than the tool's pixel budget.	{ "error": "…exceeds maxRequestBytes…" }
415	Content-Type isn't application/json on the json-body transport.	{ "error": "unsupported content-type; expected application/json" }
429	Monthly quota or the 200/min burst limit exhausted. Check Retry-After and the X-RateLimit-* headers.	{ "error": "monthly quota exceeded", "monthRemaining": 0, … }
5xx	Conversion engine failure. Safe to retry; if it persists, the input is hitting a bug — please report it.	{ "error": "…" }

Code samples

Built from the middle-second example.

# Download or substitute the example input:
#   curl -O https://xtract.bot/examples/audio-info/sample.wav
AUDIO=$(base64 -w0 < sample.wav)

curl -X POST https://api.xtract.bot/api/audio-trim \
  -H "Content-Type: application/json" \
  -H "Accept: application/octet-stream" \
  -H "X-Account-Id: $XTRACT_ACCOUNT_ID" \
  -H "X-Api-Key: $XTRACT_API_KEY" \
  -d '{
  "startSeconds": 0.5,
  "endSeconds": 1.5,
  "audio": "'"$AUDIO"'"
}'