openenv/pr_751/en/environments/terminus.md

Terminus Environment

terminus_env is a single-tool coding environment backed by E2B Code Interpreter. Each OpenEnv episode creates a fresh E2B sandbox, runs optional setup commands, keeps shell state and files isolated for that episode, and runs optional verify commands when the agent submits a final answer.

The tool shape follows the Terminus-style "one tool" idea: agents do their work through a single terminal entrypoint rather than a notebook/toolbox surface.

Tool

• terminal(command="", final_answer=""): run a shell command inside the session sandbox, or submit a final answer and run verification.

Quick Start

from terminus_env import TerminusEnv

with TerminusEnv(base_url="http://localhost:8000").sync() as env:
    env.reset(
        setup=["mkdir -p /home/user/work"],
        verify=["test -f /home/user/work/answer.txt"],
    )
    print(env.call_tool("terminal", command="echo done > /home/user/work/answer.txt"))
    print(env.call_tool("terminal", final_answer="done"))

Local Server

cd envs/terminus_env
E2B_API_KEY=e2b_... uv run --project . server

The API and custom terminal web UI are served on port 8000. The UI is mounted at /web.

Docker

cd envs/terminus_env
openenv build -t terminus-env
docker run -p 8000:8000 -e E2B_API_KEY=e2b_... terminus-env

Configuration

• E2B_API_KEY: required when resetting an episode.
• MAX_CONCURRENT_ENVS: maximum concurrent WebSocket sessions. Defaults to 4.

Setup and Verify Commands

reset() accepts either setup / verify or setup_scripts / verify_scripts.

env.reset(
    setup=["pip install -q pytest"],
    verify=["pytest -q /home/user/work/tests"],
)

Setup failure ends the reset response with done=True and returns captured setup results. Verify commands run when terminal(final_answer="...") is called. Reward defaults to passed_verify_commands / total_verify_commands. A verify command can override this by writing a float to:

/home/user/logs/verifier/reward.txt