Vercel AI SDK

The Vercel AI SDK provider transforms Composio tools into Vercel's tool format with built-in execution, so you don't write a manual agentic loop. Each wrapped tool carries its own execute function, and the AI SDK calls it for you.

npm install @composio/core @composio/vercel ai @ai-sdk/anthropic

COMPOSIO_API_KEY=xxxxxxxxx
ANTHROPIC_API_KEY=xxxxxxxxx

import { anthropic } from "@ai-sdk/anthropic";
import { Composio } from "@composio/core";
import { VercelProvider } from "@composio/vercel";
import { generateText, stepCountIs } from "ai";

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

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

const { text } = await generateText({
  model: anthropic("claude-opus-4-6"),
  tools,
  prompt: "Send an email to john@example.com with the subject 'Hello' and body 'Hello from Composio!'",
  stopWhen: stepCountIs(10),
});

console.log(text);

Provider specifics

Strict mode. Pass strict: true to the provider to rewrite each tool's input schema into the form OpenAI strict mode (structured outputs) accepts before it reaches the AI SDK: 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 { VercelProvider } from "@composio/vercel";

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

The option does not set the AI SDK's per-tool strict flag, so the model provider does not enforce the schema. It does change what the provider accepts locally: tool-call arguments are validated against the rewritten schema, so a call that leaves out an optional parameter instead of sending null fails validation, and those nulls are dropped before the tool runs, as described above. If you set that flag yourself, use it only with OpenAI models and only on tools that did not log the warning above, since OpenAI rejects a tool that kept its original schema. Don't set it for Anthropic models: Anthropic strict mode allows at most 16 parameters with union types and 24 optional parameters across all strict tools in a request, and the rewrite turns every optional parameter into a union, so a request with about ten Composio tools is rejected. Anthropic strict mode also rejects recursive definitions and keywords such as minimum and maximum that some Composio tools use.

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