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Tool calling

PDF understanding

PDF Understanding enables the model to parse and comprehend PDF documents, extracting text and images for analysis. You can pass PDF files via URL or Base64 encoding.

PDF understanding is currently available only in China (Beijing), and calls via the Responses API are not supported at this time. If you pass a PDF using the Responses API, the call still returns HTTP 200, but the file is not delivered to the model.

Supported Models

qwen3.8-max, qwen3.8-flash, qwen3.8-27b

Quick Start

The following examples demonstrate how to send a PDF file to the model.
You must have Obtain an API key and completed Configure API key as an environment variable.
  • OpenAI Compatible
  • DashScope
  • Python
  • Node.js
  • HTTP

Sample Code

from openai import OpenAI
import os

client = OpenAI(
    # If the environment variable is not configured, replace it with your Model Studio API key: api_key="sk-xxx"
    api_key=os.getenv("DASHSCOPE_API_KEY"),
    # The following is the URL for the Singapore region. Replace {WorkspaceId} with your actual workspace ID when calling the API. URLs differ by region.
    base_url="https://{WorkspaceId}.ap-southeast-1.maas.aliyuncs.com/compatible-mode/v1",
)

completion = client.chat.completions.create(
    model="qwen3.8-max",
    messages=[
        {
            "role": "user",
            "content": [
                {
                    "type": "file",
                    "file": {
                        "file_url": "https://help-static-aliyun-doc.aliyuncs.com/file-manage-files/zh-CN/20260616/qmycjl/1506.02640v5.pdf"
                    }
                },
                {
                    "type": "text",
                    "text": "Summarize this PDF document"
                }
            ]
        }
    ],
    stream=True,
    stream_options={"include_usage": True}
)

for chunk in completion:
    if not chunk.choices:
        print(f"\nUsage: {chunk.usage}")
        continue
    delta = chunk.choices[0].delta
    if hasattr(delta, "content") and delta.content:
        print(delta.content, end="", flush=True)

Using Base64 Input

If you cannot provide a URL, you can pass the PDF file as a Base64-encoded string. The filename field is required when using file_data.
Base64 encoding increases the data size by about one third. For example, a 150 MB file becomes about 200 MB after encoding, which exceeds the request body size limit. For large files, use the URL method instead.
import base64
from openai import OpenAI
import os

client = OpenAI(
    api_key=os.getenv("DASHSCOPE_API_KEY"),
    # The following is the URL for the Singapore region. Replace {WorkspaceId} with your actual workspace ID when calling the API. URLs differ by region.
    base_url="https://{WorkspaceId}.ap-southeast-1.maas.aliyuncs.com/compatible-mode/v1",
)

# Read and encode the PDF file
with open("report.pdf", "rb") as f:
    pdf_base64 = base64.b64encode(f.read()).decode("utf-8")

completion = client.chat.completions.create(
    model="qwen3.8-max",
    messages=[
        {
            "role": "user",
            "content": [
                {
                    "type": "file",
                    "file": {
                        "file_data": f"data:application/pdf;base64,{pdf_base64}",
                        "filename": "report.pdf"
                    }
                },
                {
                    "type": "text",
                    "text": "What are the key findings in this report?"
                }
            ]
        }
    ]
)

print(completion.choices[0].message.content)

Request Parameters

The file input is specified as a content item with type: "file" (OpenAI-compatible) or as a content item containing file_url/file_data (DashScope).
The URL field only accepts a string. A list (array) of URLs is not supported.
OpenAI-compatible format:

Parameter

Type

Required

Description

file_url

string

Conditional

URL of the PDF file to download. Mutually exclusive with file_data.

file_data

string

Conditional

Base64-encoded PDF data in the format data:application/pdf;base64,.... Mutually exclusive with file_url.

filename

string

Conditional

The file name. Required when using file_data.

file_format

string

No

The file format. Currently only pdf is supported. Defaults to pdf.

Limits

Item

Limit

Maximum file size

150 MB

Maximum page count

500 pages

PDF parsing may take longer than regular text requests. The first token timeout is up to 300 seconds. We recommend using streaming output to avoid long waits.

Billing

Billing involves the following:
  • Model input tokens: Text extracted from the PDF and images parsed from pages are counted as input tokens, billed at the model's standard input token rate.
  • Document parsing fee: Charged per page of the PDF document parsed, corresponding to the metering item document_parsing (pdf).China (Beijing): $0.00275 per page.
For per-model input and output token prices, see Model inference pricing.
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