Vignette

POST /api/image-vignette2 quota units per call · cache hits free

Add a vignette to an image — soft radial darkening from the centre outward. Tune intensity and falloff. Useful for portrait emphasis, vintage looks, and focusing attention.

Multiplies the image by a radial Gaussian mask so that the centre stays bright and the corners fall off into shadow. Useful for: - Drawing the viewer's eye to a centred subject. - Vintage-photograph and cinematic looks. - Hiding noisy / busy edges in stock photography. `strength` controls how dark the corners become (0 = no effect, 1 = corners fade to black). `falloff` controls the radius of the bright region — higher values keep more of the frame bright before the darkening kicks in.

Inputs

Name	Type	Default	Description
image*	file	—	Input image bytes.
strength	number (0…1)	0.6	How dark the corners become (0 = none, 1 = black).
falloff	number (0.2…3)	1	Bright-region radius multiplier. Higher = more of the frame stays bright before the darkening kicks in.
format	enum (png \| jpeg)	"jpeg"	Output image format.

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	2 units 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	`25 MiB` (base64 inflates file payloads ~33% — the limit applies to the decoded bytes).
Max response size	`25 MiB`
Timeout	15s 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 default example.

# Download or substitute the example input:
#   curl -O https://xtract.bot/examples/image-png-to-webp/sample.png
IMAGE=$(base64 -w0 < sample.png)

curl -X POST https://api.xtract.bot/api/image-vignette \
  -H "Content-Type: application/json" \
  -H "Accept: application/octet-stream" \
  -H "X-Account-Id: $XTRACT_ACCOUNT_ID" \
  -H "X-Api-Key: $XTRACT_API_KEY" \
  -d '{
  "strength": 0.6,
  "falloff": 1,
  "format": "jpeg",
  "image": "'"$IMAGE"'"
}'