letta-server/examples/streaming

Letta Streaming Examples

Minimal examples demonstrating Letta's streaming API in both Python and TypeScript.

Setup

1. Set your Letta API key:

export LETTA_API_KEY="your_api_key_here"

2. Install dependencies:

# For TypeScript
npm install

# For Python
pip install letta-client

Run Examples

Python

python streaming_demo.py

TypeScript

npm run demo:typescript
# or directly with tsx:
npx tsx streaming_demo.ts

What These Examples Show

Both examples demonstrate:

1. Step Streaming (default) - Complete messages delivered as they're generated
2. Token Streaming - Partial chunks for real-time display (ChatGPT-like UX)

The key difference:

• Step streaming: Each event contains a complete message
• Token streaming: Multiple events per message, requiring reassembly by message ID

Key Concepts

Python

# Step streaming (default)
stream = client.agents.messages.create_stream(
    agent_id=agent.id,
    messages=[{"role": "user", "content": "Hello!"}]
)

# Token streaming
stream = client.agents.messages.create_stream(
    agent_id=agent.id,
    messages=[{"role": "user", "content": "Hello!"}],
    stream_tokens=True  # Enable token streaming
)

TypeScript

// Step streaming (default)
const stream = await client.agents.messages.createStream(
    agentId, {
        messages: [{role: "user", content: "Hello!"}]
    }
);

// Token streaming
const stream = await client.agents.messages.createStream(
    agentId, {
        messages: [{role: "user", content: "Hello!"}],
        streamTokens: true  // Enable token streaming
    }
);

Learn More

See the full documentation at docs.letta.com/guides/agents/streaming