xtract.bot

POST /api/image-bmp-to-ascii2 quota units per call · cache hits free

Convert a Windows BMP to ASCII art. Configurable width, character ramp, invert mode. Plain text or coloured HTML output.

Decodes the input BMP and renders it as ASCII art. Same options and output formats as `image-png-to-ascii`.

Inputs

NameTypeDefaultDescription
image*fileBMP bytes.
widthnumber (8…400)80Output character columns (default 80).
rampstring"standard"Preset name (standard|blocks|detailed) or a custom ramp string of at least two characters.
invertbooleanfalseFlip the luminance→character mapping.
formatenum (text | html)"text"`text` for plain ASCII; `html` for a coloured <pre> document.

Response

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

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 call2 units against the 10,000-unit monthly quota. Cache hits are free — only cache misses decrement.
Burst limit200 requests per rolling minute, shared across all tools.
Max request size2 MiB (base64 inflates file payloads ~33% — the limit applies to the decoded bytes).
Max response size5 MiB
Timeout15s wall clock.
Rate-limit headersX-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).

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

Code samples

Built from the bmp-ascii example.

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

curl -X POST https://api.xtract.bot/api/image-bmp-to-ascii \
  -H "Content-Type: application/json" \
  -H "Accept: text/plain" \
  -H "X-Account-Id: $XTRACT_ACCOUNT_ID" \
  -H "X-Api-Key: $XTRACT_API_KEY" \
  -d '{
  "width": 32,
  "image": "'"$IMAGE"'"
}'