---
title: "Compatibility and current boundaries"
description: "These docs describe the release shown in the site header. The SDK requires Python 3.10 or newer. A CLI-managed project must use the matching SDK version."
---

> M3 v0.2.16 · commit 796f6943274f075d973f267794444b91ba208010.


# Compatibility and current boundaries

These docs describe the release shown in the site header. The SDK requires
Python 3.10 or newer. A CLI-managed project must use the matching SDK version.

## Harness capabilities

| Capability | Current documented boundary |
| --- | --- |
| Direct MCP operations | Independent of an agent harness. |
| Native agent tool tests | Claude Code, OpenCode, Codex, and Pi where the selected operation is supported. |
| Bring-your-own agent | ACP v1 adapter path. |
| Agent-driven elicitation | Codex and Pi, using the tested versions and action scopes documented with the guide. |
| Direct elicitation | Sync and async SDK operations; it does not require Codex or Pi. |

Harness availability does not imply identical evidence, approval, resume,
elicitation, or cancellation behavior. Each agent guide names the tested path.

## Codex elicitation

Codex owns tool selection, dispatch, approval, retries, and cancellation. M3
observes and answers supported native requests when their association is
unambiguous. Overlapping same-server approval or elicitation cannot currently
be associated reliably and is rejected. The effective tested plan limit is
nine surfaced prompts. Prompt/resource elicitation and sampling/roots callbacks
inside a native Codex tool round are not verified supported paths.

## Pi elicitation

Pi supports the native request-key and round behavior used by M3's interaction
bridge. Its tested round capacity differs from Codex. Use the version named in
the elicitation guide and do not transfer Codex-specific limits to Pi.

## Viewer database

`m3 ui` currently opens `.m3/executions.sqlite` in the current project. It does
not accept the custom path supported by `m3 test --results-db`.

## Managed runtimes

Managed mode downloads and verifies a harness executable selected for the
current OS and CPU. It isolates that executable and writable runtime state but
is not an operating-system sandbox.