- Why a foundation model by itself cannot perform external actions reliably.
- How Bedrock Agents solve this by combining models with managed orchestration and tools.
- How your application interacts with a Bedrock Agent.
- Expected results, a key takeaway, and the next topic to explore.
Problem: models alone are not enough
Models such as Anthropic Claude and Meta Llama are excellent at generating text, code, and other outputs. However, they do not automatically perform actions against external systems. If your application needs to:- Generate an API call,
- Execute that call,
- Parse the response, and
- Iterate with follow-up calls,

Solution overview: Bedrock Agents
Bedrock Agents combine a foundation model with managed orchestration and pluggable tools (action groups). When your application invokes an agent, you specify:- The foundation model to use,
- The agent to run,
- The task or instruction to complete.
- Satisfy the request using the model alone, or
- Call one or more tools, potentially in multiple steps, until the task is complete.

Agent anatomy — core elements
An agent consists of three core elements that work together to convert intent into actions:- Foundation model — the reasoning engine that decides when and how to use tools.
- Instructions — preconfigured behavioral guidance that frames the agent’s goals and constraints (for example: “You are a customer-support assistant. Be concise and professional.”).
- Action groups (tools/APIs) — external services the agent may call. Each group can expose multiple actions (for example,
getOrderandupdateOrderfor an order-management API).

How your application interacts with an agent — typical flow
- An end user interacts with your application (where your Bedrock SDK code runs).
- Your application calls the Bedrock Agent Runtime — a different endpoint from the standard Bedrock model runtime. See the Amazon Bedrock documentation.
- Instead of calling
InvokeModelorConverse, your application callsInvokeAgentand passes the prompt/instruction. - The agent uses its configured foundation model, action groups, and an optional knowledge base (RAG — retrieval-augmented generation) to fulfill the instruction.
- The agent returns its final response to your application.
- Your application renders the result to the end user.
When interacting with an agent, call the Bedrock Agent Runtime using the
InvokeAgent method. The agent runtime handles model calls, tool execution, and RAG lookups on your behalf.- Action groups and actions are configured when you create the agent; you control which external systems the agent may access.
- A knowledge base (RAG) can be attached to provide context from your private documents; the agent can combine retrieved documents with tool usage during reasoning.
- During a single invocation the agent may perform multiple API calls or DB operations; the runtime aggregates these steps and returns a consolidated final response.

Example: minimal InvokeAgent payload
Below is a conceptual example of anInvokeAgent request payload. Use this only as a high-level guide — exact SDK or HTTP formats depend on the Bedrock client you use.
orders-api.getOrder, parse the result, and potentially call orders-api.updateOrder before returning the final output.
Summary — key takeaways
- Foundation models are excellent at generation but do not inherently perform external actions.
- Bedrock Agents combine a foundation model, instructions, and action groups into a managed agent runtime that autonomously plans and executes multi-step tasks.
- Applications should call the Bedrock Agent Runtime with
InvokeAgent— the agent handles orchestration, tool calls, and iterative reasoning. - This approach shifts integration complexity out of your application code and into a managed agent runtime, simplifying maintenance and scaling of multi-tool workflows.
InvokeAgent API.
Links and references
- Amazon Bedrock — What is Bedrock?
- Retrieval-Augmented Generation (RAG) - Wikipedia
- Anthropic Claude
- Meta Llama