Mastra

The Mastra provider transforms Composio tools into Mastra's tool format with built-in execution. Pass the wrapped tools to a Mastra Agent, and the agent calls them automatically. Each tool gets both an input and an output schema, so Mastra can validate tool results as well as arguments.

npm install @composio/core @composio/mastra @mastra/core @ai-sdk/openai

COMPOSIO_API_KEY=xxxxxxxxx
OPENAI_API_KEY=xxxxxxxxx

import { Composio } from "@composio/core";
import { MastraProvider } from "@composio/mastra";
import { Agent } from "@mastra/core/agent";
import { openai } from "@ai-sdk/openai";

const composio = new Composio({
  provider: new MastraProvider(),
});

// Create a session for your user
const session = await composio.create("user_123");
const tools = await session.tools();

const agent = new Agent({
  id: "my-agent",
  name: "My Agent",
  instructions: "You are a helpful assistant.",
  model: openai("gpt-5.2"),
  tools,
});

const { text } = await agent.generate([
  { role: "user", content: "Send an email to john@example.com with the subject 'Hello' and body 'Hello from Composio!'" },
]);

console.log(text);

Provider specifics

Strict mode. Pass strict: true to normalize each tool's input schema for OpenAI structured outputs before Mastra compiles it: every object lists all of its properties in required and is closed, and optional properties stay available but accept null. A null is dropped before the tool runs unless the tool's own schema accepts null for that parameter, so nullable fields still receive an explicit null. Tools whose schema cannot be expressed in strict mode, such as objects that accept arbitrary keys, allOf, prefixItems, or unresolved $refs, keep their original schema and log a warning:

import { Composio } from "@composio/core";
import { MastraProvider } from "@composio/mastra";

const composio = new Composio({ provider: new MastraProvider({ strict: true }) });

Next