API 文件

將 PDF 工具整合到您的工作流程

使用 iTextMaster REST API 以程式化方式生成發票和處理 PDF。所有 API 呼叫均透過 API Key 認證，並提供免費額度。

Overview

API overview

Use this page as the central API reference for authentication, endpoint patterns, Credits, response headers, and operational rules. For workflow-specific examples and FAQ, open the dedicated tool API pages from the menu.

Authenticated requests

Send x-api-key from server-side code.

Credits billing

1 successful basic PDF API call = 1 Credit.

Tool pages

Each priority API has its own examples and limits.

快速開始

兩步即可開始使用 iTextMaster API。

取得 API Key

登入您的帳戶，進入帳戶頁面，在「API 存取」區域建立 API Key。每個帳戶同時只能有一個有效的 Key。

發起首次請求

使用 cURL、fetch 或任意 HTTP 用戶端呼叫發票生成介面。

cURL

curl -X POST https://itextmaster.com/api/external/invoice-generator/pdf \
  -H 'Content-Type: application/json' \
  -H 'x-api-key: YOUR_API_KEY' \
  -d '{
    "invoiceNumber": "INV-001",
    "from": {
      "name": "Your Company",
      "email": "you@example.com",
      "addressLines": ["123 Main St", "City, Country"]
    },
    "billTo": {
      "name": "Client Name",
      "email": "client@example.com",
      "addressLines": ["456 Oak Ave", "City, Country"]
    },
    "items": [
      {
        "description": "Consulting Services",
        "quantity": 10,
        "rate": 150
      }
    ]
  }' \
  --output invoice.pdf

Developer entry points

Tool API pages

Use these dedicated pages for workflow-specific examples, limits, error codes, and FAQ.

Merge PDF APIMerge PDF files through the iTextMaster PDF Tools API. 1 Credit per successful request with cURL, Node.js, and Python examples.Split PDF APISplit PDF files into page ranges with the iTextMaster PDF Tools API. Includes cURL, Node.js, Python, Credits, limits, and errors.Rotate PDF APIRotate selected PDF pages by API. Automate page orientation fixes with iTextMaster, 1 Credit per successful request.Delete Pages APIDelete unwanted PDF pages by API. Remove blank, outdated, or sensitive pages with Credits-based PDF automation.Add Watermark APIAdd text watermarks to PDFs by API. Brand, classify, or mark documents with 1 Credit per successful request.Form Filler APIFill PDF form fields by API and optionally flatten the result. Automate PDF forms with Credits-based billing.Invoice Generator APIGenerate PDF invoices from JSON with the iTextMaster Invoice Generator API. Includes cURL, Node.js, Python, Credits, errors, and FAQ.

認證方式

所有 API 請求都需要透過 x-api-key 請求標頭傳遞 API Key。Key 以 itm_live_ 為前綴，僅在建立時顯示一次。

HTTP 請求標頭

x-api-key: itm_live_your_api_key_here

安全提示： 切勿在用戶端程式碼或公開儲存庫中暴露您的 API Key。請使用環境變數和伺服器端代理。

介面說明

POST/api/external/invoice-generator/pdf

透過 JSON 資料生成 PDF 發票。直接傳回渲染後的 PDF 檔案。

Invoice Generator API landing page

請求標頭

名稱	必填	說明
`x-api-key`	Yes	您的 API Key（itm_live_...）
`Content-Type`	Yes	application/json

請求內容

Request Body (JSON)

{
  "invoiceNumber": "INV-001",       // required
  "from": {                          // required
    "name": "Your Company",
    "email": "you@example.com",
    "phone": "+1-555-0100",
    "addressLines": ["123 Main St"],
    "taxId": "US12345678"
  },
  "billTo": {                        // required
    "name": "Client Name",
    "email": "client@example.com",
    "addressLines": ["456 Oak Ave"]
  },
  "items": [                         // required, at least 1
    {
      "description": "Consulting",
      "quantity": 10,
      "rate": 150
    }
  ],
  "currency": "USD",                 // optional, default USD
  "taxRate": 0.1,                    // optional, e.g. 0.1 = 10%
  "notes": "Payment due in 30 days", // optional
  "dueDate": "2026-05-12",           // optional
  "issueDate": "2026-04-12"          // optional
}

回應狀態碼

200PDF file with X-Credits-Charged and X-Credit-Balance headers

401{ "error": "invalid_api_key" }

402{ "error": "insufficient_credits", "creditsRequired": 1, "creditBalance": 0 }

POST/api/external/pdf-tools/:toolId

Run first-stage pdf-lib based operations through the API. Each successful API request costs 1 Credit. Failed processing attempts are refunded.

Credits

1 basic PDF API call = 1 Credit

Output

PDF for single-file results, ZIP for multi-file split results

Balance headers

Read X-Credits-Charged and X-Credit-Balance

Headers

Name	Required	Description
`x-api-key`	Yes	Your account API key.
`Content-Type`	Yes	Use application/json or multipart/form-data.

JSON request

Use this format when your app already has base64 PDF bytes.

Merge PDFs with JSON

curl -X POST https://itextmaster.com/api/external/pdf-tools/merge-pdf \
  -H 'Content-Type: application/json' \
  -H 'x-api-key: YOUR_API_KEY' \
  -d '{
    "files": [
      { "name": "a.pdf", "dataBase64": "JVBERi0xLjcK..." },
      { "name": "b.pdf", "dataBase64": "JVBERi0xLjcK..." }
    ],
    "options": {}
  }' \
  --output merged.pdf

Multipart request

Use repeated files fields for tools that accept multiple PDFs.

Split PDF with multipart/form-data

curl -X POST https://itextmaster.com/api/external/pdf-tools/split-pdf \
  -H 'x-api-key: YOUR_API_KEY' \
  -F 'file=@input.pdf;type=application/pdf' \
  -F 'options={"mode":"ranges","ranges":[{"start":1,"end":2},{"start":3,"end":5}]}' \
  --output split-results.zip

Supported tool IDs and options

toolId	Files	Example options
merge-pdf	2+ PDFs	`{}`
split-pdf	1 PDF	`{"mode":"ranges","ranges":[{"start":1,"end":3},{"start":4,"end":8}]}`
rotate-pdf	1 PDF	`{"angle":90,"pages":[1,3,5]}`
delete-pages	1 PDF	`{"pages":[2,4]}`
`extract-pages`	1 PDF	`{"pages":[1,2,5]}`
`organize-pdf`	1 PDF	`{"pageOrder":[3,1,2,4]}`
`edit-metadata`	1 PDF	`{"title":"Report","author":"iTextMaster","subject":"Q2","keywords":"pdf,api"}`
`remove-metadata`	1 PDF	`{}`
`page-numbers`	1 PDF	`{"position":"bottom-center","format":"page-of-total","startNumber":1,"fontSize":12}`
add-watermark	1 PDF	`{"type":"text","text":"CONFIDENTIAL","position":"diagonal","opacity":0.25,"fontSize":48}`
`header-footer`	1 PDF	`{"header":{"center":"{date}"},"footer":{"right":"Page {page} of {total}"},"pageRange":"all"}`
`flatten-pdf`	1 PDF	`{}`
form-filler	1 PDF	`{"fields":{"Name":"Ada Lovelace","Approved":true},"flatten":true}`
`add-blank-page`	1 PDF	`{"position":"end","pageSize":"A4"}`
`reverse-pages`	1 PDF	`{}`
`crop-pdf`	1 PDF	`{"cropBox":{"x":36,"y":36,"width":540,"height":720},"pages":"all"}`
`remove-annotations`	1 PDF	`{}`

Responses

200PDF or ZIP file with X-Credits-Charged and X-Credit-Balance headers

401{ "error": "invalid_api_key" }

402{ "error": "insufficient_credits", "creditsRequired": 1, "creditBalance": 0 }

422{ "error": "pdf_tool_processing_failed" }

Credits and limits

Credit unit

1,000 Credits = $1

Every signed-in user also receives 100 free API Credits each month.

Basic PDF API

1 Credit / call

Only API calls consume Credits. Website tools are free with no usage limits.

Operational guide

Build reliable PDF API workflows

When to choose the API

Use the API for server-side automation, scheduled jobs, batch processing, and app integrations that should run without a browser UI.
Keep manual website tools for private one-off work: website tools are free, do not require login, and do not consume Credits.
Each successful basic PDF Tools API request uses 1 Credit; failed processing attempts are refunded automatically.

Best files and requests

Use PDFs that open normally and are not encrypted, corrupted, or intentionally restricted.
Send multipart requests for normal file uploads, or JSON requests with base64 data when files already live in your app.
For large batches, process documents in smaller groups and monitor X-Credits-Charged and X-Credit-Balance headers.

Common API limits

Browser-only tools and complex WASM workflows may not be exposed as API endpoints yet.
Scanned files, unusual fonts, damaged PDFs, and complex layers can still affect output quality.
Insufficient Credits return 402 responses; every signed-in user receives 100 free API Credits each month.

Website tools vs API privacy

Website tools process files locally in the browser for private manual workflows.
API calls intentionally send files to the server so your application can automate processing.
Use website tools when you do not want to upload files; use the API when automation is more important than local-only processing.

What to do if API processing fails

Check the HTTP status, response body, and credit headers before retrying.
Retry with a smaller file, fewer pages, or a simpler request body when a PDF is very large or complex.
Unlock encrypted PDFs, repair damaged files, or test the same file in the website tool to isolate file-specific issues.

Get an API Key

Sign in to create an API Key, use your 100 monthly free API Credits, and buy additional Credits only when automation volume grows.

Create API Key View API pricing

API overview

Authenticated requests

Send x-api-key from server-side code.

Credits billing

1 successful basic PDF API call = 1 Credit.

Tool pages

Each priority API has its own examples and limits.

curl -X POST https://itextmaster.com/api/external/invoice-generator/pdf \ -H 'Content-Type: application/json' \ -H 'x-api-key: YOUR_API_KEY' \ -d '{ "invoiceNumber": "INV-001", "from": { "name": "Your Company", "email": "you@example.com", "addressLines": ["123 Main St", "City, Country"] }, "billTo": { "name": "Client Name", "email": "client@example.com", "addressLines": ["456 Oak Ave", "City, Country"] }, "items": [ { "description": "Consulting Services", "quantity": 10, "rate": 150 } ] }' \ --output invoice.pdf

介面說明

POST/api/external/invoice-generator/pdf

透過 JSON 資料生成 PDF 發票。直接傳回渲染後的 PDF 檔案。

Invoice Generator API landing page

請求標頭

名稱	必填	說明
`x-api-key`	Yes	您的 API Key（itm_live_...）
`Content-Type`	Yes	application/json

請求內容

Request Body (JSON)

{
  "invoiceNumber": "INV-001",       // required
  "from": {                          // required
    "name": "Your Company",
    "email": "you@example.com",
    "phone": "+1-555-0100",
    "addressLines": ["123 Main St"],
    "taxId": "US12345678"
  },
  "billTo": {                        // required
    "name": "Client Name",
    "email": "client@example.com",
    "addressLines": ["456 Oak Ave"]
  },
  "items": [                         // required, at least 1
    {
      "description": "Consulting",
      "quantity": 10,
      "rate": 150
    }
  ],
  "currency": "USD",                 // optional, default USD
  "taxRate": 0.1,                    // optional, e.g. 0.1 = 10%
  "notes": "Payment due in 30 days", // optional
  "dueDate": "2026-05-12",           // optional
  "issueDate": "2026-04-12"          // optional
}

回應狀態碼

200PDF file with X-Credits-Charged and X-Credit-Balance headers

401{ "error": "invalid_api_key" }

402{ "error": "insufficient_credits", "creditsRequired": 1, "creditBalance": 0 }

POST/api/external/pdf-tools/:toolId

Run first-stage pdf-lib based operations through the API. Each successful API request costs 1 Credit. Failed processing attempts are refunded.

Credits

1 basic PDF API call = 1 Credit

Output

PDF for single-file results, ZIP for multi-file split results

Balance headers

Read X-Credits-Charged and X-Credit-Balance

Headers

Name	Required	Description
`x-api-key`	Yes	Your account API key.
`Content-Type`	Yes	Use application/json or multipart/form-data.

JSON request

Use this format when your app already has base64 PDF bytes.

Merge PDFs with JSON

curl -X POST https://itextmaster.com/api/external/pdf-tools/merge-pdf \
  -H 'Content-Type: application/json' \
  -H 'x-api-key: YOUR_API_KEY' \
  -d '{
    "files": [
      { "name": "a.pdf", "dataBase64": "JVBERi0xLjcK..." },
      { "name": "b.pdf", "dataBase64": "JVBERi0xLjcK..." }
    ],
    "options": {}
  }' \
  --output merged.pdf

Multipart request

Use repeated files fields for tools that accept multiple PDFs.

Split PDF with multipart/form-data

curl -X POST https://itextmaster.com/api/external/pdf-tools/split-pdf \
  -H 'x-api-key: YOUR_API_KEY' \
  -F 'file=@input.pdf;type=application/pdf' \
  -F 'options={"mode":"ranges","ranges":[{"start":1,"end":2},{"start":3,"end":5}]}' \
  --output split-results.zip

Supported tool IDs and options

toolId	Files	Example options
merge-pdf	2+ PDFs	`{}`
split-pdf	1 PDF	`{"mode":"ranges","ranges":[{"start":1,"end":3},{"start":4,"end":8}]}`
rotate-pdf	1 PDF	`{"angle":90,"pages":[1,3,5]}`
delete-pages	1 PDF	`{"pages":[2,4]}`
`extract-pages`	1 PDF	`{"pages":[1,2,5]}`
`organize-pdf`	1 PDF	`{"pageOrder":[3,1,2,4]}`
`edit-metadata`	1 PDF	`{"title":"Report","author":"iTextMaster","subject":"Q2","keywords":"pdf,api"}`
`remove-metadata`	1 PDF	`{}`
`page-numbers`	1 PDF	`{"position":"bottom-center","format":"page-of-total","startNumber":1,"fontSize":12}`
add-watermark	1 PDF	`{"type":"text","text":"CONFIDENTIAL","position":"diagonal","opacity":0.25,"fontSize":48}`
`header-footer`	1 PDF	`{"header":{"center":"{date}"},"footer":{"right":"Page {page} of {total}"},"pageRange":"all"}`
`flatten-pdf`	1 PDF	`{}`
form-filler	1 PDF	`{"fields":{"Name":"Ada Lovelace","Approved":true},"flatten":true}`
`add-blank-page`	1 PDF	`{"position":"end","pageSize":"A4"}`
`reverse-pages`	1 PDF	`{}`
`crop-pdf`	1 PDF	`{"cropBox":{"x":36,"y":36,"width":540,"height":720},"pages":"all"}`
`remove-annotations`	1 PDF	`{}`

Responses

200PDF or ZIP file with X-Credits-Charged and X-Credit-Balance headers

401{ "error": "invalid_api_key" }

402{ "error": "insufficient_credits", "creditsRequired": 1, "creditBalance": 0 }

422{ "error": "pdf_tool_processing_failed" }

Build reliable PDF API workflows

When to choose the API

Use the API for server-side automation, scheduled jobs, batch processing, and app integrations that should run without a browser UI.
Keep manual website tools for private one-off work: website tools are free, do not require login, and do not consume Credits.
Each successful basic PDF Tools API request uses 1 Credit; failed processing attempts are refunded automatically.

Best files and requests

Use PDFs that open normally and are not encrypted, corrupted, or intentionally restricted.
Send multipart requests for normal file uploads, or JSON requests with base64 data when files already live in your app.
For large batches, process documents in smaller groups and monitor X-Credits-Charged and X-Credit-Balance headers.

Common API limits

Browser-only tools and complex WASM workflows may not be exposed as API endpoints yet.
Scanned files, unusual fonts, damaged PDFs, and complex layers can still affect output quality.
Insufficient Credits return 402 responses; every signed-in user receives 100 free API Credits each month.

Website tools vs API privacy

Website tools process files locally in the browser for private manual workflows.
API calls intentionally send files to the server so your application can automate processing.
Use website tools when you do not want to upload files; use the API when automation is more important than local-only processing.

What to do if API processing fails

Check the HTTP status, response body, and credit headers before retrying.
Retry with a smaller file, fewer pages, or a simpler request body when a PDF is very large or complex.
Unlock encrypted PDFs, repair damaged files, or test the same file in the website tool to isolate file-specific issues.

Get an API Key

Sign in to create an API Key, use your 100 monthly free API Credits, and buy additional Credits only when automation volume grows.

Create API Key View API pricing