composio-anthropic

Adapts Composio tools to the Claude Messages API tool format and executes the tool calls Claude returns.

Installation

pip install composio composio-anthropic anthropic

Set COMPOSIO_API_KEY (create one at https://dashboard.composio.dev/settings) and ANTHROPIC_API_KEY in your environment.

Quickstart

AnthropicProvider is non-agentic: Claude returns tool_use blocks, handle_tool_calls executes them, and you send the results back as tool_result blocks.

import json
import anthropic
from composio import Composio
from composio_anthropic import AnthropicProvider

composio = Composio(provider=AnthropicProvider())
client = anthropic.Anthropic()

# Create a session for your user
session = composio.create(user_id="user_123")
tools = session.tools()

messages = [
    {"role": "user", "content": "Send an email to john@example.com with the subject 'Hello' and body 'Hello from Composio!'"}
]

response = client.messages.create(
    model="claude-opus-4-6",
    max_tokens=4096,
    tools=tools,
    messages=messages,
)

# Agentic loop: keep executing tool calls until the model responds with text
while response.stop_reason == "tool_use":
    tool_use_blocks = [block for block in response.content if block.type == "tool_use"]
    results = composio.provider.handle_tool_calls(session=session, response=response)
    messages.append({"role": "assistant", "content": response.content})
    messages.append({
        "role": "user",
        "content": [
            {"type": "tool_result", "tool_use_id": tool_use_blocks[i].id, "content": json.dumps(result)}
            for i, result in enumerate(results)
        ]
    })
    response = client.messages.create(
        model="claude-opus-4-6",
        max_tokens=4096,
        tools=tools,
        messages=messages,
    )

# Print final response
for block in response.content:
    if block.type == "text":
        print(block.text)

handle_tool_calls extracts every tool_use block from the response, executes the matching Composio tools through the supplied session, and returns the raw results in order. Pass user_id instead for tools fetched with tools.get(). Claude occasionally emits tool input as a JSON string instead of an object; the provider normalizes this before execution.

Building on the Claude Agent SDK instead of the Messages API? Use composio-claude-agent-sdk.

Release files for composio-anthropic 0.21.1

For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.

Source distribution (sdist)

Source distribution for composio-anthropic 0.21.1
File	Size	Uploaded
composio_anthropic-0.21.1.tar.gz	4.1 kB	Sep 4, 2026	Details

Built distribution (wheel)

Table of built distributions (wheels) for composio-anthropic 0.21.1
File	Interpreter	ABI	Platform	Reset
composio_anthropic-0.21.1-py3-none-any.whl 4.4 kB Sep 4, 2026	Python 3	none	any	Details

Total release size: 8.4 kB

Release files / composio_anthropic-0.21.1.tar.gz

Download URL	composio_anthropic-0.21.1.tar.gz
Size	4.1 kB
Tags	Source
SHA-256 checksum How to use checksums	`5b52a23238ad6f7391cd2486b6e9f67dd0d304f8a63069a183e80852fc3c6e1e`
BLAKE2b-256 checksum How to use checksums	`1f52a51da5540810ca889857ac94e5543360aef80279af5704b5133ff9a4d2a2`
Upload date	Sep 4, 2026
Uploaded using Trusted Publishing? What is trusted publishing?	No
Uploaded via	`twine/7.0.0 CPython/3.13.14`

Release files / composio_anthropic-0.21.1-py3-none-any.whl

Download URL	composio_anthropic-0.21.1-py3-none-any.whl
Size	4.4 kB
Tags	Python 3
SHA-256 checksum How to use checksums	`c5d3a989429305968f9dbdabff973027d569b4840932b8e2bfeef1ec7cf7cda4`
BLAKE2b-256 checksum How to use checksums	`41e5ac1d435602f23107da631abfcc308b6ab35618ff28ffe0db5cad8b473c89`
Upload date	Sep 4, 2026
Uploaded using Trusted Publishing? What is trusted publishing?	No
Uploaded via	`twine/7.0.0 CPython/3.13.14`