Lord1Egypt Files API — Python
The Files API uploads files for use in Messages API requests. Reference files via file_id in content blocks, avoiding re-uploads across multiple API calls.
Beta: Pass betas=["files-api-2025-04-14"] in your API calls (the SDK sets the required header automatically).
Key Facts
- Maximum file size: 500 MB
- Total storage: 100 GB per organization
- Files persist until deleted
- File operations (upload, list, delete) are free; content used in messages is billed as input tokens
- Not available on Amazon Bedrock or Google Vertex AI
Upload a File
The file argument accepts a (filename, content, content_type) tuple, a pathlib.Path (or any PathLike — read for you, async-safe with AsyncAnthropic), or an open binary file object.
import anthropic
from pathlib import Path
client = anthropic.Anthropic()
uploaded = client.beta.files.upload(
file=("report.pdf", open("report.pdf", "rb"), "application/pdf"),
)
# or: client.beta.files.upload(file=Path("report.pdf"))
print(f"File ID: {uploaded.id}")
print(f"Size: {uploaded.size_bytes} bytes")
Use a File in Messages
PDF / Text Document
response = client.beta.messages.create(
model="{{OPUS_ID}}",
max_tokens=16000,
messages=[{
"role": "user",
"content": [
{"type": "text", "text": "Summarize the key findings in this report."},
{
"type": "document",
"source": {"type": "file", "file_id": uploaded.id},
"title": "Q4 Report", # optional
"citations": {"enabled": True} # optional, enables citations
}
]
}],
betas=["files-api-2025-04-14"],
)
for block in response.content:
if block.type == "text":
print(block.text)
Image
image_file = client.beta.files.upload(
file=("photo.png", open("photo.png", "rb"), "image/png"),
)
response = client.beta.messages.create(
model="{{OPUS_ID}}",
max_tokens=16000,
messages=[{
"role": "user",
"content": [
{"type": "text", "text": "What's in this image?"},
{
"type": "image",
"source": {"type": "file", "file_id": image_file.id}
}
]
}],
betas=["files-api-2025-04-14"],
)
Manage Files
List Files
Iterate the list result directly — the SDK auto-paginates across all pages. Only use .data if you want the first page only.
for f in client.beta.files.list():
print(f"{f.id}: {f.filename} ({f.size_bytes} bytes)")
Get File Metadata
file_info = client.beta.files.retrieve_metadata("file_011CNha8iCJcU1wXNR6q4V8w")
print(f"Filename: {file_info.filename}")
print(f"MIME type: {file_info.mime_type}")
Delete a File
client.beta.files.delete("file_011CNha8iCJcU1wXNR6q4V8w")
Download a File
Only files created by the code execution tool or skills can be downloaded (not user-uploaded files).
file_content = client.beta.files.download("file_011CNha8iCJcU1wXNR6q4V8w")
file_content.write_to_file("output.txt")
Full End-to-End Example
Upload a document once, ask multiple questions about it:
import anthropic
client = anthropic.Anthropic()
# 1. Upload once
uploaded = client.beta.files.upload(
file=("contract.pdf", open("contract.pdf", "rb"), "application/pdf"),
)
print(f"Uploaded: {uploaded.id}")
# 2. Ask multiple questions using the same file_id
questions = [
"What are the key terms and conditions?",
"What is the termination clause?",
"Summarize the payment schedule.",
]
for question in questions:
response = client.beta.messages.create(
model="{{OPUS_ID}}",
max_tokens=16000,
messages=[{
"role": "user",
"content": [
{"type": "text", "text": question},
{
"type": "document",
"source": {"type": "file", "file_id": uploaded.id}
}
]
}],
betas=["files-api-2025-04-14"],
)
print(f"\nQ: {question}")
text = next((b.text for b in response.content if b.type == "text"), "")
print(f"A: {text[:200]}")
# 3. Clean up when done
client.beta.files.delete(uploaded.id)