@agent-builder/sdk

TypeScript client SDK for Agent Builder. A thin wrapper over the official @anthropic-ai/sdk that points your client at a deployed Agent Builder agent's Anthropic Messages-compatible endpoint.

Phase 2 item 2.11 — pairs with the Anthropic-compatible endpoint shipped in Phase 2 item 2.15.

Install

npm install @agent-builder/sdk @anthropic-ai/sdk
# or
pnpm add @agent-builder/sdk @anthropic-ai/sdk
# or
yarn add @agent-builder/sdk @anthropic-ai/sdk

@anthropic-ai/sdk is a peer dependency so you can pin your own version.

Quick start

import { createAgentClient } from '@agent-builder/sdk';

const client = createAgentClient({
  agentUrl: 'https://my-agent.agents.buildragent.ai',
  apiKey: process.env.AGENT_BUILDER_API_KEY!,
});

// Non-streaming
const response = await client.messages.create({
  model: 'claude-sonnet-4-6', // server-configured, ignored
  max_tokens: 4096,
  messages: [{ role: 'user', content: 'Hello!' }],
});

console.log(response.content);

// Streaming
const stream = client.messages.stream({
  model: 'claude-sonnet-4-6',
  max_tokens: 4096,
  messages: [{ role: 'user', content: 'Write a poem.' }],
});

for await (const event of stream) {
  if (event.type === 'content_block_delta' && event.delta.type === 'text_delta') {
    process.stdout.write(event.delta.text);
  }
}

What's different from the raw Anthropic SDK

The deployed agent at agentUrl is configured with a specific system prompt, model, tools, and other parameters that its tenant chose at deploy time. When you call messages.create through this SDK:

• model in your request is ignored. The agent's deployed model is always used.
• system in your request is ignored. The agent's deployed system prompt is always used.
• tools in your request is ignored. The agent's deployed tool set is always used.
• messages, max_tokens, and other per-turn fields work as expected.

The Authorization: Bearer <apiKey> header is attached automatically — the tenant UI issues per-app API keys (Phase 1 item 1.3 Mode B) that the deployed agent's middleware validates.

Advanced

createAgentClient accepts any ClientOptions the Anthropic SDK understands (minus baseURL and apiKey, which the wrapper manages). Useful knobs:

createAgentClient({
  agentUrl: '...',
  apiKey: '...',
  maxRetries: 5,
  timeout: 60_000,
  defaultHeaders: {
    'x-request-id': 'my-correlation-id',
  },
});

Raw Anthropic SDK access

If you need the raw client for direct Anthropic API calls alongside your agent calls, import it from this package:

import { Anthropic } from '@agent-builder/sdk';

const rawClient = new Anthropic({ apiKey: process.env.ANTHROPIC_API_KEY! });

This avoids having to list @anthropic-ai/sdk separately in your imports when you're already depending on this package.