microsoft--agent-framework/python/packages/monty/AGENTS.md

Monty Package (agent-framework-monty)

Monty-backed CodeAct integrations for the Microsoft Agent Framework.

Note

Beta package. Included in agent-framework[all] and available through the lazy-loading namespace agent_framework.monty.

Core Classes

• MontyCodeActProvider — ContextProvider that injects a run-scoped execute_code tool plus dynamic CodeAct instructions. Mirrors the HyperlightCodeActProvider API for the parts that apply to a non-sandboxed Python interpreter.
• MontyExecuteCodeTool — FunctionTool that wraps the Monty interpreter. Use directly for mixed-tool agents or manual static wiring. Mirrors HyperlightExecuteCodeTool.

Public API

from agent_framework.monty import (
    FileMount,
    FileMountInput,
    MontyCodeActProvider,
    MontyExecuteCodeTool,
    MountMode,
)

MontyCodeActProvider and MontyExecuteCodeTool both accept:

• tools — host tool callables / FunctionTools
• approval_mode — "never_require" (default) or "always_require"
• workspace_root — host directory auto-mounted at /input (mirrors HyperlightCodeActProvider.workspace_root)
• file_mounts — sequence of FileMountInput (str shorthand, (host_path, mount_path) tuple, or FileMount)
• resource_limits — Monty ResourceLimits TypedDict

Tool-management methods on both classes: add_tools, get_tools, remove_tool, clear_tools. Mount-management methods: add_file_mounts, get_file_mounts, remove_file_mount, clear_file_mounts.

MontyExecuteCodeTool additionally exposes:

• build_instructions(*, tools_visible_to_model: bool) -> str
• create_run_tool() -> MontyExecuteCodeTool
• build_serializable_state() -> dict[str, Any]
• workspace_root, resource_limits properties

Architecture

• _types.py — FileMount, FileMountInput, MountMode (public).
• _provider.py — MontyCodeActProvider (thin wrapper around the tool).
• _execute_code_tool.py — MontyExecuteCodeTool plus tool / mount normalization, approval helpers, dynamic description/instructions builders, and the post-execution file-capture flow that surfaces files written to read-write mounts as Content.from_data items.
• _monty_bridge.py — InlineCodeBridge and generate_type_stubs, adapted from the reference Monty CodeAct repo. Pauses on FunctionSnapshot to dispatch host calls, then resumes; supports direct typed tool calls, the call_tool fallback, asyncio.gather fan-out, and forwards mount / limits to Monty(...).start(...).
• _instructions.py — dynamic instruction / tool-description builders (include filesystem capability summaries when mounts are configured).

Not implemented (yet)

Capability	Monty primitive	Status
Custom virtual filesystem	OSAccess subclass passed to Monty(...).start(os=...)	Not exposed. Strictly more general than file mounts; useful when you want a fully synthetic FS.
Outbound URL allow-list	No Monty primitive — expose fetch_url as a host tool with the allow-list check in your tool function.	Not exposed in this package; users add it as a regular tool.

Out of scope (for now)

• Durable execution — the reference Monty CodeAct repo also offers a Durable-Functions-backed mode (DurableCodeBridge, register_durable_codeact, wait_for_external_event, per-tool approval via external events). That is intentionally not in this package yet.