@adcp/client

Official TypeScript/JavaScript client for the Ad Context Protocol (AdCP). Build distributed advertising operations that work synchronously OR asynchronously with the same code.

The Core Concept

AdCP operations are distributed and asynchronous by default. An agent might:

• Complete your request immediately (synchronous)
• Need time to process and send results via webhook (asynchronous)
• Ask for clarifications before proceeding
• Send periodic status updates as work progresses

Your code stays the same. You write handlers once, and they work for both sync completions and webhook deliveries.

Installation

npm install @adcp/client

Quick Start: Distributed Operations

import { ADCPMultiAgentClient } from '@adcp/client';

// Configure agents and handlers
const client = new ADCPMultiAgentClient([
  {
    id: 'agent_x',
    agent_uri: 'https://agent-x.com',
    protocol: 'a2a'
  },
  {
    id: 'agent_y',
    agent_uri: 'https://agent-y.com/mcp/',
    protocol: 'mcp'
  }
], {
  // Webhook URL template (macros: {agent_id}, {task_type}, {operation_id})
  webhookUrlTemplate: 'https://myapp.com/webhook/{task_type}/{agent_id}/{operation_id}',

  // Activity callback - fires for ALL events (requests, responses, status changes, webhooks)
  onActivity: (activity) => {
    console.log(`[${activity.type}] ${activity.task_type} - ${activity.operation_id}`);
    // Log to monitoring, update UI, etc.
  },

  // Status change handlers - called for ALL status changes (completed, failed, input-required, working, etc)
  handlers: {
    onGetProductsStatusChange: (response, metadata) => {
      // Called for sync completion, async webhook, AND status changes
      console.log(`[${metadata.status}] Got products for ${metadata.operation_id}`);

      if (metadata.status === 'completed') {
        db.saveProducts(metadata.operation_id, response.products);
      } else if (metadata.status === 'failed') {
        db.markFailed(metadata.operation_id, metadata.message);
      } else if (metadata.status === 'input-required') {
        // Handle clarification needed
        console.log('Needs input:', metadata.message);
      }
    }
  }
});

// Execute operation - library handles operation IDs, webhook URLs, context management
const agent = client.agent('agent_x');
const result = await agent.getProducts({ brief: 'Coffee brands' });

// onActivity fired: protocol_request
// onActivity fired: protocol_response

// Check result
if (result.status === 'completed') {
  // Agent completed synchronously!
  console.log('✅ Sync completion:', result.data.products.length, 'products');
  // onGetProductsStatusChange handler ALREADY fired with status='completed' ✓
}

if (result.status === 'submitted') {
  // Agent will send webhook when complete
  console.log('⏳ Async - webhook registered at:', result.submitted?.webhookUrl);
  // onGetProductsStatusChange handler will fire when webhook arrives ✓
}

Handling Clarifications (input-required)

When an agent needs more information, you can continue the conversation:

const result = await agent.getProducts({ brief: 'Coffee brands' });

if (result.status === 'input-required') {
  console.log('❓ Agent needs clarification:', result.metadata.inputRequest?.question);
  // onActivity fired: status_change (input-required)

  // Continue the conversation with the same agent
  const refined = await agent.continueConversation('Only premium brands above $50');
  // onActivity fired: protocol_request
  // onActivity fired: protocol_response

  if (refined.status === 'completed') {
    console.log('✅ Got refined results:', refined.data.products.length);
    // onGetProductsStatusChange handler fired ✓
  }
}

Webhook Pattern

All webhooks (task completions AND notifications) use one endpoint with flexible URL templates.

Configure Your Webhook URL Structure

const client = new ADCPMultiAgentClient(agents, {
  // Path-based (default pattern)
  webhookUrlTemplate: 'https://myapp.com/webhook/{task_type}/{agent_id}/{operation_id}',

  // OR query string
  webhookUrlTemplate: 'https://myapp.com/webhook?agent={agent_id}&op={operation_id}&type={task_type}',

  // OR custom path
  webhookUrlTemplate: 'https://myapp.com/api/v1/adcp/{agent_id}?operation={operation_id}',

  // OR namespace to avoid conflicts
  webhookUrlTemplate: 'https://myapp.com/adcp-webhooks/{agent_id}/{task_type}/{operation_id}'
});

Single Webhook Endpoint

// Handles ALL webhooks (task completions and notifications)
app.post('/webhook/:task_type/:agent_id/:operation_id', async (req, res) => {
  const { task_type, agent_id, operation_id } = req.params;

  // Route to agent client - handlers fire automatically
  const agent = client.agent(agent_id);
  await agent.handleWebhook(
    req.body,
    task_type,
    operation_id,
    req.headers['x-adcp-signature'],
    req.headers['x-adcp-timestamp']
  );

  res.json({ received: true });
});

URL Generation is Automatic

const operationId = createOperationId();
const webhookUrl = agent.getWebhookUrl('sync_creatives', operationId);
// Returns: https://myapp.com/webhook/sync_creatives/agent_x/op_123
// (or whatever your template generates)

Activity Events

Get observability into everything happening:

const client = new ADCPMultiAgentClient(agents, {
  onActivity: (activity) => {
    console.log({
      type: activity.type,              // 'protocol_request', 'webhook_received', etc.
      operation_id: activity.operation_id,
      agent_id: activity.agent_id,
      status: activity.status
    });

    // Stream to UI, save to database, send to monitoring
    eventStream.send(activity);
  }
});

Activity types:

• protocol_request - Request sent to agent
• protocol_response - Response received from agent
• status_change - Task status changed
• webhook_received - Webhook received from agent

Notifications (Agent-Initiated)

Mental Model: Notifications are operations that get set up when you create a media buy. The agent sends periodic updates (like delivery reports) to the webhook URL you configured during media buy creation.

// When creating a media buy, agent registers for delivery notifications
const result = await agent.createMediaBuy({
  campaign_id: 'camp_123',
  budget: { amount: 10000, currency: 'USD' }
  // Agent internally sets up recurring delivery_report notifications
});

// Later, agent sends notifications to your webhook
const client = new ADCPMultiAgentClient(agents, {
  handlers: {
    onMediaBuyDeliveryNotification: (notification, metadata) => {
      console.log(`Report #${metadata.sequence_number}: ${metadata.notification_type}`);

      // notification_type indicates progress:
      // 'scheduled' → Progress update (like status: 'working')
      // 'final' → Operation complete (like status: 'completed')
      // 'delayed' → Still waiting (extended timeline)

      db.saveDeliveryUpdate(metadata.operation_id, notification);

      if (metadata.notification_type === 'final') {
        db.markOperationComplete(metadata.operation_id);
      }
    }
  }
});

Notifications use the same webhook URL pattern as regular operations:

POST https://myapp.com/webhook/media_buy_delivery/agent_x/delivery_report_agent_x_2025-10

The operation_id is lazily generated from agent + month: delivery_report_{agent_id}_{YYYY-MM}

All intermediate reports for the same agent + month → same operation_id

Type Safety

Full TypeScript support with IntelliSense:

// All responses are fully typed
const result = await agent.getProducts(params);
// result: TaskResult<GetProductsResponse>

if (result.success) {
  result.data.products.forEach(p => {
    console.log(p.name, p.price); // Full autocomplete!
  });
}

// Handlers receive typed responses
handlers: {
  onCreateMediaBuyStatusChange: (response, metadata) => {
    // response: CreateMediaBuyResponse | CreateMediaBuyAsyncWorking | ...
    // metadata: WebhookMetadata
    if (metadata.status === 'completed') {
      const buyId = (response as CreateMediaBuyResponse).media_buy_id; // Typed!
    }
  }
}

Multi-Agent Operations

Execute across multiple agents simultaneously:

const client = new ADCPMultiAgentClient([agentX, agentY, agentZ]);

// Parallel execution across all agents
const results = await client.allAgents().getProducts({ brief: 'Coffee brands' });
// results: TaskResult<GetProductsResponse>[]

const agentIds = client.getAgentIds();
results.forEach((result, i) => {
  console.log(`${agentIds[i]}: ${result.status}`);

  if (result.status === 'completed') {
    console.log(`  Sync: ${result.data?.products?.length} products`);
  } else if (result.status === 'submitted') {
    console.log(`  Async: webhook to ${result.submitted?.webhookUrl}`);
  }
});

Security

Webhook Signature Verification

const client = new ADCPMultiAgentClient(agents, {
  webhookSecret: process.env.WEBHOOK_SECRET
});

// Signatures verified automatically on handleWebhook()
// Returns 401 if signature invalid

Authentication

const agents = [{
  id: 'agent_x',
  name: 'Agent X',
  agent_uri: 'https://agent-x.com',
  protocol: 'a2a',
  auth_token: process.env.AGENT_X_TOKEN // ✅ Secure - load from env
}];

Environment Configuration

# .env
WEBHOOK_URL_TEMPLATE="https://myapp.com/webhook/{task_type}/{agent_id}/{operation_id}"
WEBHOOK_SECRET="your-webhook-secret"

ADCP_AGENTS_CONFIG='[
  {
    "id": "agent_x",
    "name": "Agent X",
    "agent_uri": "https://agent-x.com",
    "protocol": "a2a",
    "auth_token": "actual-token-here"
  }
]'

// Auto-discover from environment
const client = ADCPMultiAgentClient.fromEnv();

Available Tools

All AdCP tools with full type safety:

Media Buy Lifecycle:

• getProducts() - Discover advertising products
• listCreativeFormats() - Get supported creative formats
• createMediaBuy() - Create new media buy
• updateMediaBuy() - Update existing media buy
• syncCreatives() - Upload/sync creative assets
• listCreatives() - List creative assets
• getMediaBuyDelivery() - Get delivery performance

Audience & Targeting:

• getSignals() - Get audience signals
• activateSignal() - Activate audience signals
• providePerformanceFeedback() - Send performance feedback

Protocol:

• getAdcpCapabilities() - Get agent capabilities (v3)

Property Discovery (AdCP v2.2.0)

Build agent registries by discovering properties agents can sell. Works with AdCP v2.2.0's publisher-domain model.

How It Works

1. Agents return publisher domains: Call listAuthorizedProperties() → get publisher_domains[]
2. Fetch property definitions: Get https://{domain}/.well-known/adagents.json from each domain
3. Index properties: Build fast lookups for "who can sell X?" and "what can agent Y sell?"

Three Key Queries

import { PropertyCrawler, getPropertyIndex } from '@adcp/client';

// First, crawl agents to discover properties
const crawler = new PropertyCrawler();
await crawler.crawlAgents([
  { agent_url: 'https://agent-x.com', protocol: 'a2a' },
  { agent_url: 'https://agent-y.com/mcp/', protocol: 'mcp' }
]);

const index = getPropertyIndex();

// Query 1: Who can sell this property?
const matches = index.findAgentsForProperty('domain', 'cnn.com');
// Returns: [{ property, agent_url, publisher_domain }]

// Query 2: What can this agent sell?
const auth = index.getAgentAuthorizations('https://agent-x.com');
// Returns: { agent_url, publisher_domains: [...], properties: [...] }

// Query 3: Find by tags
const premiumProperties = index.findAgentsByPropertyTags(['premium', 'ctv']);

Full Example

import { PropertyCrawler, getPropertyIndex } from '@adcp/client';

const crawler = new PropertyCrawler();

// Crawl agents - gets publisher_domains from each, then fetches adagents.json
const result = await crawler.crawlAgents([
  { agent_url: 'https://sales.cnn.com' },
  { agent_url: 'https://sales.espn.com' }
]);

console.log(`✅ ${result.successfulAgents} agents`);
console.log(`📡 ${result.totalPublisherDomains} publisher domains`);
console.log(`📦 ${result.totalProperties} properties indexed`);

// Now query
const index = getPropertyIndex();
const whoCanSell = index.findAgentsForProperty('ios_bundle', 'com.cnn.app');

for (const match of whoCanSell) {
  console.log(`${match.agent_url} can sell ${match.property.name}`);
}

Property Types

Supports 18 identifier types: domain, subdomain, ios_bundle, android_package, apple_app_store_id, google_play_id, roku_channel_id, podcast_rss_feed, and more.

Use Case

Build a registry service that:

• Periodically crawls agents with PropertyCrawler
• Persists discovered properties to a database
• Exposes fast query APIs using the in-memory index patterns
• Provides web UI for browsing properties and agents

Library provides discovery logic - you add persistence layer.

Database Schema

Simple unified event log for all operations:

CREATE TABLE webhook_events (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  operation_id TEXT NOT NULL,        -- Groups related events
  agent_id TEXT NOT NULL,
  task_type TEXT NOT NULL,           -- 'sync_creatives', 'media_buy_delivery', etc.
  status TEXT,                       -- For tasks: 'submitted', 'working', 'completed'
  notification_type TEXT,            -- For notifications: 'scheduled', 'final', 'delayed'
  sequence_number INTEGER,           -- For notifications: report sequence
  payload JSONB NOT NULL,
  timestamp TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

CREATE INDEX idx_events_operation ON webhook_events(operation_id);
CREATE INDEX idx_events_agent ON webhook_events(agent_id);
CREATE INDEX idx_events_timestamp ON webhook_events(timestamp DESC);

-- Query all events for an operation
SELECT * FROM webhook_events
WHERE operation_id = 'op_123'
ORDER BY timestamp;

-- Get all delivery reports for agent + month
SELECT * FROM webhook_events
WHERE operation_id = 'delivery_report_agent_x_2025-10'
ORDER BY sequence_number;

CLI Tool

For development and testing, use the included CLI tool to interact with AdCP agents.

Quick Start with Aliases

Save agents for quick access:

# Save an agent with an alias
npx @adcp/client --save-auth test https://test-agent.adcontextprotocol.org

# Use the alias
npx @adcp/client test get_products '{"brief":"Coffee brands"}'

# List saved agents
npx @adcp/client --list-agents

Direct URL Usage

Auto-detect protocol and call directly:

# Protocol auto-detection (default)
npx @adcp/client https://test-agent.adcontextprotocol.org get_products '{"brief":"Coffee"}'

# Force specific protocol with --protocol flag
npx @adcp/client https://agent.example.com get_products '{"brief":"Coffee"}' --protocol mcp
npx @adcp/client https://agent.example.com list_authorized_properties --protocol a2a

# List available tools
npx @adcp/client https://agent.example.com

# Use a file for payload
npx @adcp/client https://agent.example.com create_media_buy @payload.json

# JSON output for scripting
npx @adcp/client https://agent.example.com get_products '{"brief":"..."}' --json | jq '.products'

Authentication

Three ways to provide auth tokens (priority order):

# 1. Explicit flag (highest priority)
npx @adcp/client test get_products '{"brief":"..."}' --auth your-token

# 2. Saved in agent config (recommended)
npx @adcp/client --save-auth prod https://prod-agent.com
# Will prompt for auth token securely

# 3. Environment variable (fallback)
export ADCP_AUTH_TOKEN=your-token
npx @adcp/client test get_products '{"brief":"..."}'

Agent Management

# Save agent with auth
npx @adcp/client --save-auth prod https://prod-agent.com mcp

# List all saved agents
npx @adcp/client --list-agents

# Remove an agent
npx @adcp/client --remove-agent test

# Show config file location
npx @adcp/client --show-config

Protocol Auto-Detection: The CLI automatically detects whether an endpoint uses MCP or A2A by checking URL patterns and discovery endpoints. Override with --protocol mcp or --protocol a2a if needed.

Config File: Agent configurations are saved to ~/.adcp/config.json with secure file permissions (0600).

See docs/CLI.md for complete CLI documentation including webhook support for async operations.

Testing

Try the live testing UI at http://localhost:8080 when running the server:

npm start

Features:

• Configure multiple agents (test agents + your own)
• Execute ONE operation across all agents
• See live activity stream (protocol requests, webhooks, handlers)
• View sync vs async completions side-by-side
• Test different scenarios (clarifications, errors, timeouts)

Examples

Basic Operation

const result = await agent.getProducts({ brief: 'Coffee brands' });

With Clarification Handler

const result = await agent.createMediaBuy(
  { buyer_ref: 'campaign-123', account_id: 'acct-456', packages: [...] },
  (context) => {
    // Agent needs more info
    if (context.inputRequest.field === 'budget') {
      return 50000; // Provide programmatically
    }
    return context.deferToHuman(); // Or defer to human
  }
);

With Webhook for Long-Running Operations

const operationId = createOperationId();

const result = await agent.syncCreatives(
  { creatives: largeCreativeList },
  null, // No clarification handler = webhook mode
  {
    contextId: operationId,
    webhookUrl: agent.getWebhookUrl('sync_creatives', operationId)
  }
);

// Result will be 'submitted', webhook arrives later
// Handler fires when webhook received

Contributing

Contributions welcome! See CONTRIBUTING.md for guidelines.

License

Apache 2.0 License - see LICENSE file for details.

Support

• Documentation: docs.adcontextprotocol.org
• Issues: GitHub Issues
• Protocol Spec: AdCP Specification