Releases

Changelog

Notable changes to the ChangeThisFile API and SDKs.

This changelog covers the public HTTP API. Conversion-engine improvements (new routes, format upgrades) are tracked in the formats catalogue.

2026-04-25 — source auto-detect #

  • POST /v1/convert and POST /v1/jobs no longer require a source field — the API detects the input format from the filename extension and falls back to a magic-byte sniff for renamed uploads. The endpoint is now file in, file out: pass file + target and you're done. source is still accepted to override.

2026-04-25 — v1 launch #

The first stable release of the ChangeThisFile API.

Public API #

  • POST /v1/convert — synchronous conversion, returns the converted file inline.
  • POST /v1/jobs — async conversion jobs with polling and webhook callbacks.
  • GET /v1/jobs/{id} — job status with 24h signed download URLs.
  • GET /v1/jobs — paginated job listing (newest first).
  • GET /v1/usage — current plan + monthly consumption.
  • POST /v1/keys/free — issue a free-tier API key (no card).
  • POST /v1/webhooks/secret — rotate the webhook signing secret.
  • POST /v1/webhooks/test — send a test event to verify your endpoint.
  • GET /v1/plans — public plan catalogue.
  • POST /v1/billing/checkout — Stripe Checkout for upgrades.
  • POST /v1/billing/portal — Stripe customer-portal session.

Design philosophy #

No SDKs. The endpoint is the SDK. One POST with a file and a target gets you back the converted bytes — that's all most callers need. Webhook verification is ~25 lines of stdlib HMAC in any language; ready-to-paste snippets are in Webhooks and Idempotency.

Format coverage #

  • 689 conversion routes across 103 formats in 11 categories (image, video, audio, document, spreadsheet, ebook, archive, font, data, devops, subtitle).
  • 176 client-side routes (browser canvas, heic2any, mammoth, etc. — used by the web app).
  • 513 server-side routes (FFmpeg, LibreOffice, Calibre, 7-Zip, sharp, Ghostscript, dcraw, fonttools — used by the API).

Pricing #

  • Free: 1,000 conv/mo, 25 MB file cap.
  • Hobby: $19/mo, 5,000 conv/mo, 100 MB.
  • Startup: $49/mo, 25,000 conv/mo, 500 MB.
  • Scale: $149/mo, 100,000 conv/mo, 1 GB.
  • Growth: $499/mo, 500,000 conv/mo, 5 GB.
  • Enterprise: custom.

Annual plans get 20% off vs. monthly.

Operational features #

  • Idempotency-Key header (Stripe-style, 24h replay window) on /v1/convert and /v1/jobs.
  • HMAC-signed webhooks with X-CTF-Signature: t=...,v1=... header and 5-minute replay tolerance.
  • Standard rate-limit headers (X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Reset) on every response.
  • Structured error envelope with stable machine-readable code field.