Short answer: there isn’t a built‑in way to make a single

marvin.run(..., cli=True)

call stay open forever. The CLI “prompt” is a tool, not a session manager. To keep an interactive session going, the supported pattern is to run a loop yourself and persist state across turns with a Thread (for chat history) and optional Memory (for long‑term facts). A few specifics: - In current Marvin,

marvin.run

does not take a

cli

flag. The “CLI” is available as a tool at

marvin.tools.interactive.cli.cli

. You can add that tool to an agent so it can ask the user questions during a single run, but it won’t keep the run open indefinitely. - For a REPL that survives multiple messages, keep a single Thread (optionally with a fixed

id

so it’s restorable) and loop on input/output. Attach a shared Memory if you want durable recall across sessions. Example REPL pattern (supported/recommended):

from marvin import Agent, Thread, Memory, run
from marvin.tools.interactive.cli import cli as ask_user

# Optional long-term memory shared across runs
mem = Memory(key="my-long-term-mem", description="Long-term facts about the user/session")

assistant = Agent(
    name="Assistant",
    instructions="You are a helpful assistant.",
    tools=[ask_user],          # lets the agent ask the user for input mid-run
    memories=[mem],            # long-term memory (optional)
)

# Use a stable thread id to persist conversation history to the local DB
thread = Thread(id="my-cli-session")

print("Type 'quit' to exit.")
with thread:
    while True:
        user = input("You: ")
        if user.strip().lower() in {"quit", "exit"}:
            break

        # Use marvin.run so we can explicitly pass thread and agent(s)
        reply = run(user, agents=[assistant], thread=thread)
        print(f"Assistant: {reply}")

Notes: - Thread maintains short‑term message history; it’s persisted to a local SQLite DB by default. You can change the DB via

MARVIN_DATABASE_URL

. - Memory stores long‑term facts retrievable across sessions; using the same Memory key lets you share it across runs/threads. - The CLI tool (

ask_user

) is useful if the agent needs to ask follow‑up questions within a single run, but it won’t keep the run “open” on its own. Docs for deeper reference: - Interactivity pattern: Interactivity - Threads: Threads concept - Memory: Memory pattern If you can share which Marvin version you’re on, I can tailor an example exactly to it. But in current Marvin, the “loop + persistent Thread (+ optional Memory)” pattern is the supported way to run indefinitely. Your current approach is on the right track—just swap to a single Thread to avoid “new interactive runs” and keep history clean.