PDFThin API

Overview

All uploads use multipart/form-data. Responses are JSON.

• Base URL: https://pdfthin.com (or your SITE_URL).
• Rate limit: RATE_LIMIT_RPM per IP (default 60/min).
• Max upload: MAX_UPLOAD_MB (default 200 MB).
• Files auto-delete after 60 hours.
• Supported inputs: PDF file; optional watermark PNG/JPG up to 5MB.
• Upload variants: single file (optimize/split) or multiple files (organize).

Server configuration

Key environment variables that affect API behavior.

• REDIS_URL: job queue and status storage.
• S3_ENDPOINT/S3_BUCKET/S3_ACCESS_KEY/S3_SECRET_KEY: object storage (optional, else local).
• Files auto-delete after 60 hours.
• RATE_LIMIT_RPM and DOWNLOAD_TOKEN_TTL_MIN.

Create job (optimize or split)

POST /api/jobs with multipart/form-data.

• mode=split ignores quality and returns parts if needed.
• When quality is set, preset/custom_mb are ignored.
• When quality_mode=smart, the API tries high-to-low quality to fit the size.

curl -X POST https://pdfthin.com/api/jobs   -F "[email protected]"   -F "preset=gmail25"   -F "mode=optimize"

curl -X POST https://pdfthin.com/api/jobs   -F "[email protected]"   -F "preset=custom"   -F "custom_mb=12"   -F "quality_mode=smart"   -F "mode=optimize"

curl -X POST https://pdfthin.com/api/jobs   -F "[email protected]"   -F "quality=printer"   -F "mode=optimize"

Create job (organize)

Use mode=organize to merge, rotate, delete, reorder, and split pages.

• If multiple files are uploaded they are merged in upload order.
• At least one operation or multiple files is required.

curl -X POST https://pdfthin.com/api/jobs   -F "[email protected]"   -F "[email protected]"   -F "mode=organize"   -F "rotate_angle=90"   -F "rotate_pages=1-2"

Check status

GET /api/jobs/{id} returns job state and result files.

• Status values: queued | processing | done | failed.

{
  "id": "job-id",
  "status": "done",
  "progress_pct": 100,
  "expires_at": "2026-01-22T11:02:51Z",
  "result": {
    "kind": "single",
    "files": [
      {
        "name": "output.pdf",
        "size": 503937,
        "download_url": "/api/jobs/job-id/download?index=0"
      }
    ]
  }
}

Download results

GET /api/jobs/{id}/download?index=0

• Use index=0..n for multi-part outputs.
• If called without token, the API returns a redirect with a short-lived token.
• Token TTL is DOWNLOAD_TOKEN_TTL_MIN minutes.

curl -L "https://pdfthin.com/api/jobs/job-id/download?index=0" -o output.pdf

Delete job

DELETE /api/jobs/{id} removes stored files and status.

• Returns 204 No Content.

curl -X DELETE https://pdfthin.com/api/jobs/job-id

Error codes

Errors use JSON: {"error":{"code":"...","message":"..."}}

• ERR_INVALID_FILE
• ERR_TOO_LARGE
• ERR_PASSWORD_PROTECTED
• ERR_CANNOT_FIT_SINGLE_PAGE
• ERR_TIMEOUT
• ERR_INTERNAL
• ERR_NOT_FOUND
• ERR_NOT_READY
• ERR_TOKEN_USED
• ERR_FORBIDDEN

OpenAPI (draft)

Minimal OpenAPI 3.0 snippet for quick integration.

openapi: 3.0.3
info:
  title: PDFThin API
  version: "1.0"
paths:
  /api/jobs:
    post:
      summary: Create a job
      requestBody:
        required: true
        content:
          multipart/form-data:
            schema:
              type: object
              properties:
                file:
                  type: string
                  format: binary
                mode:
                  type: string
                preset:
                  type: string
                custom_mb:
                  type: integer
                quality:
                  type: string
                quality_mode:
                  type: string
                watermark:
                  type: string
                  format: binary
      responses:
        "202":
          description: Accepted
  /api/jobs/{id}:
    get:
      summary: Get job status
      parameters:
        - in: path
          name: id
          required: true
          schema:
            type: string
      responses:
        "200":
          description: OK
    delete:
      summary: Delete job
      parameters:
        - in: path
          name: id
          required: true
          schema:
            type: string
      responses:
        "204":
          description: No Content
  /api/jobs/{id}/download:
    get:
      summary: Download result
      parameters:
        - in: path
          name: id
          required: true
          schema:
            type: string
        - in: query
          name: index
          schema:
            type: integer
      responses:
        "303":
          description: See Other