Built-in Tools

The Tools subsystem provides managed providers for Amazon Bedrock AgentCore’s two built-in tool types: Code Interpreter and Browser. Both integrate as Gateway targets — the Gateway proxies calls to AWS-managed services. There is no local SDK client or lifecycle management in your agent code.

Architecture guide: Tools, MCP & Gateway

Key Classes

Class Module Purpose
CodeInterpreterProvider agent_core.tools.code_interpreter Discovers Code Interpreter tools from the Gateway by code-interpreter:: prefix
BrowserProvider agent_core.tools.browser Discovers Browser tools from the Gateway by browser:: prefix
BuiltinToolWiring agent_core.tools.wiring Reads blueprint tools: block and wires both providers automatically

How It Works

Both providers follow the same pattern: receive a GatewayClient, call list_tools_sync(), and filter by namespace prefix. The agent sees these tools alongside domain tools:

Agent --> Gateway --> Code Interpreter (AWS-managed sandbox)
                 --> Browser (AWS-managed Chromium)
                 --> Domain MCP servers

start() and stop() on both providers are no-ops — lifecycle is managed entirely by AgentCore Gateway.

Code Interpreter

Runs Python and shell commands in an isolated, ephemeral sandbox managed by AgentCore.

from agent_core.tools import CodeInterpreterProvider

provider = CodeInterpreterProvider(gateway_client=gateway)
ci_tools = provider.tools   # Cached after first Gateway discovery

agent = Agent(model=model, tools=local_tools + ci_tools)

Tool names are discovered dynamically from the Gateway by filtering for the code-interpreter:: prefix. Do not hardcode tool names — the available set is managed by AWS and may change.

Blueprint declaration:

tools:
  - builtin: code_interpreter
    network_mode: PUBLIC    # PUBLIC (default) | PRIVATE

Browser

Provides hosted Chromium access via CDP (Chrome DevTools Protocol) and Nova Act for natural-language navigation.

from agent_core.tools import BrowserProvider

provider = BrowserProvider(gateway_client=gateway)
browser_tools = provider.tools   # Cached after first Gateway discovery

agent = Agent(model=model, tools=local_tools + browser_tools)

Tool names are discovered dynamically by filtering for the browser:: prefix.

Blueprint declaration:

tools:
  - builtin: browser

BuiltinToolWiring

Automates registration of all declared built-in providers:

from agent_core.tools import BuiltinToolWiring

wiring = BuiltinToolWiring(gateway_client=gateway, blueprint=blueprint)
builtin_tools = wiring.discover_tools()

agent = Agent(model=model, tools=local_tools + gateway_tools + builtin_tools)

When using BlueprintLoader, builtin tool wiring is handled automatically — the loader reads the tools: block and discovers tools without any code.

Blueprint Declaration

All three tool declaration types in the blueprint tools: list:

tools:
  # MCP server tools (via Gateway target)
  - mcp: my-domain-mcp
    tools: [get_record, search_records]   # Empty list = all tools

  # Built-in Gateway-managed tools
  - builtin: code_interpreter
  - builtin: browser

  # Remote agent as a tool (A2A)
  - a2a: summarization-agent             # Blueprint ID or URL

See Also

Built-in Tools

The Tools subsystem provides managed providers for Amazon Bedrock AgentCore’s two built-in tool types: Code Interpreter and Browser. Both integrate as Gateway targets — the Gateway proxies calls to AWS-managed services, so there is no local SDK client or session management.

Key Classes

Class Purpose
CodeInterpreterProvider Discovers Code Interpreter tools from the Gateway and caches them
BrowserProvider Discovers Browser tools from the Gateway and caches them
BuiltinToolWiring Registers both providers as Gateway targets and wires them to the Strands agent

How It Works

Both providers follow the same pattern: they receive a GatewayClient, call list_tools_sync() to discover available tools, and filter for their target namespace. The agent sees these tools alongside domain tools — it doesn’t know or care that they’re AWS-managed services.

Agent --> Gateway --> Code Interpreter (AWS-managed sandbox)
                 --> Browser (AWS-managed Chromium + Nova Act)
                 --> Domain MCP servers

Code Interpreter

The Code Interpreter runs Python and shell commands in an isolated, ephemeral sandbox managed by AgentCore. The Gateway proxies all calls — no local session management needed.

Blueprint Declaration 

tools:
  - builtin: code_interpreter
  - mcp: my-domain-mcp
    tools: [custom_tool]

Provider Pattern 

from agent_core.tools import CodeInterpreterProvider

# The provider discovers tools from Gateway — no session() or execute()
provider = CodeInterpreterProvider(gateway_client=gateway)
ci_tools = provider.tools  # Cached after first discovery

# Tools are added to the agent alongside other Gateway tools
agent = Agent(model=model, tools=local_tools + ci_tools)

Tool names are discovered dynamically from the Gateway at runtime by filtering for the code-interpreter:: prefix — they are not defined in the platform code. The actual names exposed under this prefix are determined by the AWS AgentCore managed service. Refer to AWS AgentCore documentation for the current tool name list.

Browser

The Browser provides hosted Chromium access via CDP (Chrome DevTools Protocol) and Nova Act for natural-language navigation. Like Code Interpreter, it’s Gateway-mediated.

Blueprint Declaration 

tools:
  - builtin: browser
  - builtin: code_interpreter

Provider Pattern 

from agent_core.tools import BrowserProvider

provider = BrowserProvider(gateway_client=gateway)
browser_tools = provider.tools  # Cached after first discovery

agent = Agent(model=model, tools=local_tools + browser_tools)

Tool names are discovered dynamically from the Gateway by filtering for the browser:: prefix. The actual names are determined by the AWS AgentCore managed Browser service — refer to AWS AgentCore documentation for the current tool list.

BuiltinToolWiring

BuiltinToolWiring automates the registration of both providers when the blueprint declares them:

from agent_core.tools import BuiltinToolWiring

wiring = BuiltinToolWiring(gateway_client=gateway, blueprint=blueprint)
builtin_tools = wiring.discover_tools()

# Returns combined tools from all declared builtins
agent = Agent(model=model, tools=local_tools + gateway_tools + builtin_tools)

When using BlueprintLoader, this wiring is handled automatically — the loader reads the tools: block and wires builtins without any code.

See Also