Retrieval (RAG)

Grounds agent responses with WithRetrievers. Pick one backend per run.

Backend	Entrypoint
Weaviate	`go run ./agent_with_retriever/weaviate`
PostgreSQL + pgvector	`go run ./agent_with_retriever/pgvector`

Sample KB documents are seeded by Task infra. Edit docker/weaviate/sample-documents.json or docker/pgvector/sample-documents.json and re-run up to change corpus content. Source: examples/agent_with_retriever/

Retriever modes

Set RETRIEVER_MODE in .env (default agentic):

Mode	Behavior
`agentic`	Retriever exposed as a tool; LLM decides when to search
`prefetch`	Search runs once before the first LLM call; context injected into system prompt
`hybrid`	Prefetch and retriever tools

Prefetch/hybrid embed your exact user message — use concrete questions aligned with the sample KB (returns, shipping, warranty, etc.).

Setup

From examples/:

task infra:status

Weaviate:

task infra:weaviate:up
go run ./agent_with_retriever/weaviate "What is the return policy?"
task infra:weaviate:down

pgvector:

task infra:pgvector:up
go run ./agent_with_retriever/pgvector "What is the return policy?"
task infra:pgvector:down

Run examples

# Agentic (default)
go run ./agent_with_retriever/weaviate "What is the return policy?"

# Prefetch — search before first LLM call
RETRIEVER_MODE=prefetch go run ./agent_with_retriever/weaviate "What are the return and shipping rules?"

# Hybrid
RETRIEVER_MODE=hybrid go run ./agent_with_retriever/pgvector "Summarize warranty coverage."

Use SHOW_TELEMETRY=true to compare prefetch vs agentic search counts.

Expected output

Our return policy allows returns within 30 days of purchase with a receipt.
Items must be in their original condition. Sale items are final sale.

The response is grounded in the sample KB documents seeded by task infra:weaviate:up / task infra:pgvector:up. With SHOW_TELEMETRY=true in agentic mode you’ll see total_retriever_searches: 1.

Before You Begin

Basic Agents

Configuration

Tools & MCP

Streaming & AG-UI

Memory & RAG

Observability & Hooks

A2A

Multi-agent

Durable & Distributed

Retriever modes

Setup

Run examples

Expected output

Learn more

Retrieval

Memory

​Retriever modes

​Setup

​Run examples

​Expected output

​Learn more

Retrieval

Memory

Retriever modes

Setup

Run examples

Expected output

Learn more