How to integrate PromptLayer MCP with Claude Agent SDK

This guide walks you through connecting PromptLayer to the Claude Agent SDK using the Composio tool router. By the end, you'll have a working PromptLayer agent that can browse your prompt templates, inspect request logs, list registered tools, and review saved workflows through natural language commands. This guide will help you understand how to give your Claude Agent SDK agent real control over a PromptLayer account through Composio's PromptLayer MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

PromptLayer logoPromptLayer
Api Key

PromptLayer is a prompt management and observability platform for LLM apps. Use it to version prompts, run evaluations, trace requests, and analyze model behavior.

16 Tools

Introduction

This guide walks you through connecting PromptLayer to the Claude Agent SDK using the Composio tool router. By the end, you'll have a working PromptLayer agent that can browse your prompt templates, inspect request logs, list registered tools, and review saved workflows through natural language commands.

This guide will help you understand how to give your Claude Agent SDK agent real control over a PromptLayer account through Composio's PromptLayer MCP server.

Before we dive in, let's take a quick look at the key ideas and tools involved.

Also integrate PromptLayer with

TL;DR

Here's what you'll learn:
  • Get and set up your Claude/Anthropic and Composio API keys
  • Install the necessary dependencies
  • Initialize Composio and create a Tool Router session for PromptLayer
  • Configure an AI agent that can use PromptLayer as a tool
  • Run a live chat session where you can ask the agent to perform PromptLayer operations

What is Claude Agent SDK?

The Claude Agent SDK is Anthropic's official framework for building AI agents powered by Claude. It provides a streamlined interface for creating agents with MCP tool support and conversation management.

Key features include:

  • Native MCP Support: Built-in support for Model Context Protocol servers
  • Permission Modes: Control tool execution permissions
  • Streaming Responses: Real-time response streaming for interactive applications
  • Context Manager: Clean async context management for sessions

What is the PromptLayer MCP server, and what's possible with it?

The PromptLayer MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your PromptLayer account. It provides structured and secure access to your prompts, request logs, workflows, tools, skill collections, and tables, so your agent can find prompt templates, inspect LLM activity, browse workflows, review registered resources, and analyze table data on your behalf.

  • Prompt discovery and inspection: Have your agent search prompt templates and retrieve specific versions, messages, model settings, snippets, or release details for review.
  • Request monitoring and analysis: Instruct your agent to search LLM request logs and inspect recorded inputs, outputs, timing, usage, metadata, tags, and scores.
  • Workflow and tool exploration: Let the agent find workflows and registered tools, then retrieve their definitions without running them.
  • Skill and workspace browsing: Direct your agent to browse folders, registry items, and skill collections, including the files stored in a selected collection.
  • Table data review: Have your agent find tables, inspect their sheets and columns, and read rows with optional schema and execution summaries.

What is the Composio tool router, and how does it fit here?

What is Composio SDK?

Composio's Composio SDK helps agents find the right tools for a task at runtime. You can plug in multiple toolkits (like Gmail, HubSpot, and GitHub), and the agent will identify the relevant app and action to complete multi-step workflows. This can reduce token usage and improve the reliability of tool calls. Read more here: Getting started with Composio SDK

The tool router generates a secure MCP URL that your agents can access to perform actions.

How the Composio SDK works

The Composio SDK follows a three-phase workflow:

  1. Discovery: Searches for tools matching your task and returns relevant toolkits with their details.
  2. Authentication: Checks for active connections. If missing, creates an auth config and returns a connection URL via Auth Link.
  3. Execution: Executes the action using the authenticated connection.

Step-by-step Guide

Step by step09 STEPS
1

Prerequisites

Before starting, make sure you have:
  • Composio API Key and Claude/Anthropic API Key
  • Primary know-how of Claude Agents SDK
  • A PromptLayer account
  • Some knowledge of Python
2

Getting API Keys for Claude/Anthropic and Composio

Claude/Anthropic API Key
  • Go to the Anthropic Console and create an API key. You'll need credits to use the models.
  • Keep the API key safe.
Composio API Key
  • Log in to the Composio dashboard.
  • Navigate to your API settings and generate a new API key.
  • Store this key securely as you'll need it for authentication.
3

Install dependencies

npm install @anthropic-ai/claude-agent-sdk @composio/core dotenv

Install the Composio SDK and the Claude Agents SDK.

What's happening:

  • @composio/core provides Composio integration for Anthropic
  • @anthropic-ai/claude-agent-sdk is the core agent framework
  • dotenv/config loads environment variables
4

Set up environment variables

bash
COMPOSIO_API_KEY=your_composio_api_key_here
USER_ID=your_user_id_here
ANTHROPIC_API_KEY=your_anthropic_api_key_here

Create a .env file in your project root.

What's happening:

  • COMPOSIO_API_KEY authenticates with Composio
  • USER_ID identifies the user for session management
  • ANTHROPIC_API_KEY authenticates with Anthropic/Claude
5

Import dependencies

import 'dotenv/config';
import readline from 'node:readline';
import { Composio } from '@composio/core';
import { query, type Options } from "@anthropic-ai/claude-agent-sdk";

dotenv.config();
What's happening:
  • We're importing all necessary libraries including the Claude Agent SDK and Composio
  • The dotenv.config() function loads environment variables from your .env file
  • This setup prepares the foundation for connecting Claude with PromptLayer functionality
6

Create a Composio instance and Tool Router session

async function chat() {
  const { COMPOSIO_API_KEY, USER_ID } = process.env;
  if (!COMPOSIO_API_KEY || !USER_ID) {
    throw new Error('COMPOSIO_API_KEY and USER_ID required in .env');
  }

  const composio = new Composio({ apiKey: COMPOSIO_API_KEY });

  // Create Tool Router session for PromptLayer
  const session = await composio.create(USER_ID, {
    toolkits: ['promptlayer'],
  });
  const mcpUrl = session?.mcp.url;
What's happening:
  • The function checks for the required COMPOSIO_API_KEY environment variable
  • We're creating a Composio instance using our API key
  • The create method creates a Tool Router session for PromptLayer
  • The returned url is the MCP server URL that your agent will use
7

Configure Claude Agent with MCP

const options: Options = {
  permissionMode: 'bypassPermissions',
  mcpServers: {
    composio: {
      type: 'http',
      url: mcpUrl,
      headers: { 'x-api-key': COMPOSIO_API_KEY }
    }
  },
  systemPrompt: 'You are a helpful assistant with access to PromptLayer tools via Composio.',
  maxTurns: 10,
};
What's happening:
  • We're configuring the Claude Agent options with the MCP server URL
  • permissionMode: 'bypassPermissions' allows the agent to execute operations without asking for permission each time
  • The system prompt instructs the agent that it has access to PromptLayer
  • maxTurns: 10 limits the conversation length to prevent excessive API usage
8

Create client and start chat loop

const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
    prompt: 'You: '
  });

  console.log('\nChat started. Type "exit" to quit.\n');

  let isProcessing = false;

  async function ask(prompt: string) {
    isProcessing = true;
    rl.pause();

    process.stdout.write('Claude is thinking...');
    const stream = query({ prompt, options });

    let firstChunk = true;
    for await (const msg of stream) {
      const content = (msg as any).message?.content || (msg as any).content;
      if (Array.isArray(content)) {
        for (const block of content) {
          if (block.type === 'text' && block.text) {
            if (firstChunk) {
              process.stdout.write('\r\x1b[K');
              process.stdout.write('Claude: ');
              firstChunk = false;
            }
            process.stdout.write(block.text);
          }
        }
      }
    }
    process.stdout.write('\n\n');

    isProcessing = false;
    rl.resume();
    rl.prompt();
  }

  rl.on('line', async (line) => {
    if (isProcessing) return;

    const input = line.trim();
    if (input === 'exit') {
      rl.close();
      process.exit(0);
    }
    if (input) await ask(input);
    else rl.prompt();
  });

  await ask('What can you help me with?');
}
What's happening:
  • The readline interface is created to handle user input and output
  • The query function is used to send the user's input to the agent
  • The chat loop continues until the user types 'exit' or 'quit'
9

Run the application

try {
  await chat();
} catch (error) {
  console.error(error);
  process.exit(1);
}
What's happening:
  • The chat function is the entry point for the application
  • The try-catch block is used to handle any errors that occur

Complete Code

Here's the complete code to get you started with PromptLayer and Claude Agent SDK:

import 'dotenv/config';
import readline from 'node:readline';
import { Composio } from '@composio/core';
import { query, type Options } from "@anthropic-ai/claude-agent-sdk";

async function chat() {
  const { COMPOSIO_API_KEY, USER_ID } = process.env;
  if (!COMPOSIO_API_KEY || !USER_ID) {
    throw new Error('COMPOSIO_API_KEY and USER_ID required in .env');
  }

  const composio = new Composio({ apiKey: COMPOSIO_API_KEY });
  const session = await composio.create(USER_ID, {
    toolkits: ['promptlayer']
  });
  const mcp_url = session?.mcp.url;

  const options: Options = {
    permissionMode: 'bypassPermissions',
    mcpServers: {
      composio: {
        type: 'http',
        url: mcp_url,
        headers: { 'x-api-key': COMPOSIO_API_KEY }
      }
    },
    systemPrompt: 'You are a helpful assistant with access to PromptLayer tools via Composio.',
    maxTurns: 10,
  };

  const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
    prompt: 'You: '
  });

  console.log('\nChat started. Type "exit" to quit.\n');

  let isProcessing = false;

  async function ask(prompt: string) {
    isProcessing = true;
    rl.pause();

    process.stdout.write('Claude is thinking...');
    const stream = query({ prompt, options });

    let firstChunk = true;
    for await (const msg of stream) {
      const content = (msg as any).message?.content || (msg as any).content;
      if (Array.isArray(content)) {
        for (const block of content) {
          if (block.type === 'text' && block.text) {
            if (firstChunk) {
              process.stdout.write('\r\x1b[K');
              process.stdout.write('Claude: ');
              firstChunk = false;
            }
            process.stdout.write(block.text);
          }
        }
      }
    }
    process.stdout.write('\n\n');

    isProcessing = false;
    rl.resume();
    rl.prompt();
  }

  rl.on('line', async (line) => {
    if (isProcessing) return;

    const input = line.trim();
    if (input === 'exit') {
      rl.close();
      process.exit(0);
    }
    if (input) await ask(input);
    else rl.prompt();
  });

  await ask('What can you help me with?');
}

try {
  await chat();
} catch (error) {
  console.error(error);
  process.exit(1);
}

Conclusion

You've successfully built a Claude Agent SDK agent that can interact with PromptLayer through Composio's Tool Router.

Key features:

  • Native MCP support through Claude's agent framework
  • Streaming responses for real-time interaction
  • Permission bypass for smooth automated workflows
You can extend this by adding more toolkits, implementing custom business logic, or building a web interface around the agent.
TOOLS

Supported Tools

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

Get Prompt Template

Retrieve a prompt template version, release label, messages, model metadata, snippets, and optionally provider-ready kwargs without executing it.

Get Registered Tool

Retrieve a PromptLayer registered tool definition by ID or name at a selected version or release label without test execution.

Get Request Log

Retrieve one PromptLayer request log with its recorded input, output, timing, usage, metadata, tags, and scores.

Get Skill Collection

Retrieve a PromptLayer skill collection and its files as JSON at a selected version or release label.

Get Table

Retrieve one PromptLayer Table's metadata and per-sheet row counts by UUID.

Get Workflow

Retrieve a PromptLayer workflow definition by ID or name at a specific version or release label without running it.

List Folder Entities

Browse or search PromptLayer folders and registry entities in the API-key workspace, optionally recursively and with metadata.

List Prompt Templates

Search and page through PromptLayer prompt templates and snippets without executing a model.

List Registered Tools

List and filter tools defined in PromptLayer's tool registry without executing them.

List Skill Collections

List and filter PromptLayer skill collections available in the API-key workspace.

List Table Columns

List one page of user and optionally system columns for a PromptLayer Table sheet.

List Table Rows

Read one page of rows and cells from a PromptLayer Table sheet, with optional schema and execution aggregates.

List Tables

Search and page through PromptLayer Tables by folder, name, or referenced prompt.

List Table Sheets

List one page of sheets in a PromptLayer Table, optionally filtering by referenced prompt.

List Workflows

Search and page through PromptLayer workflows without running them.

Search Request Logs

Search PromptLayer request logs by text or structured filters and return one rate-limited page sorted by operational fields.

FAQ

Frequently asked questions

With a standalone PromptLayer MCP server, the agents and LLMs can only access a fixed set of PromptLayer tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from PromptLayer and many other apps based on the task at hand, all through a single MCP endpoint.

Yes, you can. Claude Agent SDK fully supports MCP integration. You get structured tool calling, message history handling, and model orchestration while Tool Router takes care of discovering and serving the right PromptLayer tools.

Yes, absolutely. You can configure which PromptLayer scopes and actions are allowed when connecting your account to Composio. You can also bring your own OAuth credentials or API configuration so you keep full control over what the agent can do.

All sensitive data such as tokens, keys, and configuration is fully encrypted at rest and in transit. Composio is SOC 2 Type 2 compliant and follows strict security practices so your PromptLayer data and credentials are handled as safely as possible.

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