Invalid Bounce MCP server for AI agents and assistants

Securely connect your AI agents and chatbots (Claude, ChatGPT, Cursor, etc) with Invalid Bounce MCP or direct API to verify email addresses, validate bulk lists, flag risky contacts, and clean marketing data through natural language.

Invalid Bounce logoInvalid Bounce
Api Key

Invalid Bounce is an email verification service with a bulk verification API. Use it to clean email lists, reduce bounces, and protect sender reputation.

1 Tools

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TOOL ROUTER PLAYGROUND
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TOOLS

Supported Tools

Every Invalid Bounce action and event your agent gets out of the box.

Start Bulk Email Verification

Irreversibly start an asynchronous email-verification job using the connected account's verification quota.

SETUP GUIDE

Connect Invalid Bounce MCP Tool with your Agent

1

Install Composio

typescript
npm install @composio/core ai @ai-sdk/mcp @ai-sdk/openai
Install the Composio SDK and your agent framework
2

Create a session with MCP enabled

typescript
import { Composio } from "@composio/core";

const composio = new Composio();
const { mcp } = await composio.create("your-user-id", {
  toolkits: ["invalid_bounce"],
  mcp: true,
});
Create a session scoped to Invalid Bounce and read its MCP URL and headers
3

Connect your agent to the MCP server

typescript
import { createMCPClient } from "@ai-sdk/mcp";
import { openai } from "@ai-sdk/openai";
import { generateText, stepCountIs } from "ai";

const client = await createMCPClient({
  transport: { type: "http", url: mcp.url, headers: mcp.headers },
});

const { text } = await generateText({
  model: openai("gpt-5.6-sol"),
  tools: await client.tools(),
  prompt: "Verify these email addresses with Invalid Bounce: alice@example.com, sales@invalid-domain.test, support@company.com",
  stopWhen: stepCountIs(10),
});

console.log(text);
await client.close();
Pass the session's MCP URL and headers to your agent and run a Invalid Bounce request
SETUP GUIDE

Connect Invalid Bounce API Tool with your Agent

1

Install Composio

typescript
npm install @composio/core @composio/openai openai
Install the Composio SDK, the OpenAI provider, and the OpenAI SDK
2

Create a Composio session

typescript
import OpenAI from "openai";
import { Composio } from "@composio/core";
import { OpenAIResponsesProvider } from "@composio/openai";

const composio = new Composio({ provider: new OpenAIResponsesProvider() });
const client = new OpenAI();

const session = await composio.create("your-user-id", { toolkits: ["invalid_bounce"] });
const tools = await session.tools();
Initialize Composio with the OpenAI Responses provider and create a session scoped to Invalid Bounce
3

Run Invalid Bounce tools with your agent

typescript
let response = await client.responses.create({
  model: "gpt-5.6-sol",
  tools,
  input: [{ role: "user", content: "Verify these email addresses with Invalid Bounce: alice@example.com, sales@invalid-domain.test, support@company.com" }],
});

while (response.output.some((o) => o.type === "function_call")) {
  const outputs = await composio.provider.handleToolCalls(session, response.output);
  response = await client.responses.create({
    model: "gpt-5.6-sol",
    tools,
    previous_response_id: response.id,
    input: outputs,
  });
}

console.log(response.output_text);
Send a request, execute the Invalid Bounce tool calls through the session, and print the final answer

Why Use Composio?

AI Native Invalid Bounce Integration

  • Supports both Invalid Bounce MCP and direct API based integrations
  • Structured, LLM-friendly schemas for reliable email verification workflows
  • Rich coverage for checking addresses, validating bulk lists, and reviewing verification results

Managed Auth

  • Securely store Invalid Bounce API keys without hard-coding them in your agent code
  • Use auth_configs.create() and connected_accounts.link() to connect user credentials cleanly
  • Manage per user and per environment access from one place

Agent Optimized Design

  • Tools are shaped for natural language requests like verifying campaign lists or checking CRM imports
  • Comprehensive execution logs so you always know which emails were checked, when, and on whose behalf

Enterprise Grade Security

  • Fine-grained RBAC so you control which agents and users can access Invalid Bounce
  • Scoped, least privilege access for email validation workflows
  • Full audit trail of agent actions to support review and compliance
FAQ

Frequently asked questions

Yes, Invalid Bounce requires you to configure your own API key. Once set up, Composio handles secure credential storage and API request handling for you.

Yes! Composio's Tool Router enables agents to use multiple toolkits. Learn more.

Yes. Composio is SOC 2 Type II compliant and is built to keep your Invalid Bounce connection and credentials secure. OAuth tokens and API keys are encrypted, and sensitive customer data is protected at rest and in transit.

Composio also undergoes independent security testing and continuously monitors its systems for security threats. You can review the latest reports and policies in the Composio Trust Center.

Composio maintains and updates all toolkit integrations automatically, so your agents always work with the latest API versions.

Create the key in your Invalid Bounce account settings, then paste it once on Composio's connection page. Composio stores it encrypted and uses it only for the Invalid Bounce actions your agent runs. Nobody else in your workspace can read it, and you can revoke it inside Invalid Bounce at any time.

When you connect a Invalid Bounce account through Composio, every action runs under that account, so anything the agent creates, sends, or changes shows up in Invalid Bounce as done by you. Keep an approval step in your prompt for actions with side effects, such as sending or deleting, and have the agent draft first.

Whatever the credentials you connect allow inside Invalid Bounce. If Invalid Bounce lets you scope a key to specific permissions, create a scoped one so the agent can only do what you intend. You can revoke the key inside Invalid Bounce at any time.

Yes. Composio supports multiple connected accounts for the same app, and that works in Claude, ChatGPT, or any other assistant you connect through Composio. Give each Invalid Bounce connection a name such as work or personal, and the assistant uses the one you mention in the request. Each account keeps its own credentials and nothing is merged.

The connection stops working the moment Invalid Bounce rejects the old key. Create a new key in Invalid Bounce and reconnect the account from the Composio dashboard or by asking your agent to reconnect Invalid Bounce. Nothing else changes.

Composio's free Hobby plan includes 100,000 tool calls per month with no credit card, which covers most personal Invalid Bounce use. Paid plans add higher limits and team features. Your Invalid Bounce plan and its API limits still apply as usual.

Built-in connectors usually give one AI access to a limited set of apps. Many people use Composio because it lets their AI connect to more apps than it normally supports, or connect to multiple accounts for the same app (e.g. connect Claude to multiple Invalid Bounce accounts).

With Composio, you connect Invalid Bounce once and then use it across different AI assistants without setting it up separately in each one. Connect your apps to Composio once, then connect Composio to whichever AI you use, whether that's Claude, ChatGPT, Hermes, or your own custom assistant.

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