feat: add python e2b sandbox example

[xxchan]

Summary

• Add a self-contained Python example that runs Kimi Agent SDK inside an E2B sandbox.
• Vendor the E2BKaos (KAOS backend) implementation into the example as a reference for extending KAOS: examples/python/e2b-sandbox/e2b_kaos.py.
• Wire the example to use the vendored backend (no dependency on kaos.contrib.e2b / no kimi-cli dev-branch pin).

Files

• examples/python/e2b-sandbox/e2b_kaos.py: vendored E2BKaos backend
• examples/python/e2b-sandbox/main.py: set_current_kaos(E2BKaos(...))
• examples/python/e2b-sandbox/README.md: setup & run
• README.md: list Python examples

Reference

• feat(kaos): add E2B sandbox integration kimi-cli#659

Testing

• cd python && uv sync --frozen && uv run ruff check && uv run pyright && uv run pytest -q
• E2B runtime not exercised locally (requires E2B_API_KEY + a live sandbox)

[Copilot]

Pull request overview

This PR adds a self-contained Python example showing how to run the Kimi Agent SDK inside an E2B sandbox by vendoring an E2BKaos KAOS backend and wiring it into the example.

Changes:

• Add an E2BKaos implementation that adapts KAOS filesystem/process APIs to an E2B AsyncSandbox.
• Add an example driver script, agent configuration, and example-local pyproject.toml to run the SDK in an E2B sandbox.
• Update the top-level README to list the new Python example alongside existing Go examples.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
examples/python/e2b-sandbox/pyproject.toml	Defines an example-local project, Python version, and dependencies (including e2b and the local kimi-agent-sdk source) to make the sandbox example self-contained.
examples/python/e2b-sandbox/main.py	Implements the async entrypoint that validates E2B_API_KEY, configures workdir, creates an E2B sandbox, installs E2BKaos as the current KAOS backend, and runs the SDK prompt loop.
examples/python/e2b-sandbox/e2b_kaos.py	Provides the E2BKaos KAOS backend, mapping KAOS operations (paths, stat, file IO, mkdir, exec) onto the E2B sandbox APIs, with async process/stdin/stdout handling.
examples/python/e2b-sandbox/agent.yaml	Configures an e2b agent profile extending the default and disables the Grep tool for non-local KAOS usage.
examples/python/e2b-sandbox/README.md	Documents KAOS, explains how E2B integration works, provides a code snippet, and adds end-to-end run instructions for the example.
README.md	Adds a concise “Examples” section linking to existing Go examples and the new Python E2B sandbox example.

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[Copilot]

In the "How It Works" code snippet, E2BKaos is used but never imported, so readers copying this snippet as-is will get a NameError. Please add the missing import (e.g., importing E2BKaos from e2b_kaos) to keep the example self-contained and runnable.

[Copilot]

The README suggests that setting E2B_SANDBOX_ID will cause the script to connect to an existing sandbox ("If E2B_SANDBOX_ID is not set, the script creates a sandbox..."), but main.py's _get_sandbox currently ignores E2B_SANDBOX_ID and always calls AsyncSandbox.create. Please either implement the E2B_SANDBOX_ID connect flow in _get_sandbox (as hinted in the commented-out code) or update this section of the README to reflect the current behavior so users are not misled.

Suggested change

	If `E2B_SANDBOX_ID` is not set, the script creates a sandbox and prints the ID. The sandbox lifecycle is managed outside of the SDK.
	This example currently always creates a new sandbox instance and prints its ID; `E2B_SANDBOX_ID` is reserved for future use, and the sandbox lifecycle is managed outside of the SDK.