--- title: Python Quickstart icon: /images/python-logo.svg description: Create a Mirage Python workspace, mount RAM as a virtual filesystem, and run shell commands that read, write, search, and transform files. keywords: ["Mirage Python quickstart", "mirage-ai", "virtual filesystem", "AI agents", "shell commands"] --- ## Installation Install Mirage: ```bash uv add mirage-ai ``` If you are not using uv: ```bash pip install mirage-ai ``` For resources with extra dependencies, install the matching extra: ```bash uv add "mirage-ai[s3]" ``` ## Create a Workspace Start with the RAM resource so you can try Mirage without credentials. ```python import asyncio from mirage import MountMode, Workspace from mirage.resource.ram import RAMResource async def main() -> None: ws = Workspace({"/data": RAMResource()}, mode=MountMode.WRITE) await ws.execute('echo "hello mirage" | tee /data/hello.txt') result = await ws.execute("cat /data/hello.txt") print(await result.stdout_str()) await ws.close() asyncio.run(main()) ``` ## Run Commands Once a resource is mounted, you can use Mirage like a shell over your virtual filesystem: ```python import asyncio from mirage import MountMode, Workspace from mirage.resource.ram import RAMResource async def main() -> None: ws = Workspace({"/data": RAMResource()}, mode=MountMode.WRITE) await ws.execute('echo \'{"name": "alice"}\' | tee /data/user.json') result = await ws.execute("ls /data/") print(await result.stdout_str()) result = await ws.execute("cat /data/hello.txt") print(await result.stdout_str()) result = await ws.execute('jq ".name" /data/user.json') print(await result.stdout_str()) result = await ws.execute("grep hello /data/hello.txt") print(await result.stdout_str()) await ws.close() asyncio.run(main()) ``` ## Estimate Before You Run `execute(..., provision=True)` returns a `ProvisionResult` instead of running the command: network/cache bytes, read ops, and a `precision` telling you how much to trust the numbers (`exact`, `range`, `unknown` -- totals under `unknown` are floors). Pipelines, `&&`/`||`, `if`/`case`, loops, and subshells aggregate automatically. ```python plan = await ws.execute("cat /data/user.json | wc -l", provision=True) print(plan.network_read, plan.read_ops, plan.precision) ``` Read commands are estimated out of the box on every backend. When you register your own command, pass `provision=` to the `@command` decorator (reuse a helper like `make_file_read_provision(my_stat)` or `default_provision(name, my_stat)` from `mirage.commands.builtin.generic_bind`), or omit it and the planner reports `unknown`. Full semantics live in the [CLI provision docs](/home/cli#5-dry-run-with-provision). ## Output Safeguards To keep huge reads from flooding an agent, `cat`, `grep`, `rg`, `head`, and `tail` cap their **final** output at 2000 lines by default. When a cap fires, the agent sees the truncated bytes plus a stderr notice (`output truncated at safeguard limit (2000 lines); ...`); exit code stays 0. Caps fire only on the **terminal** command of a pipeline, so `cat big.txt | head -n 30` still shows 30 lines. ### Configure per mount Limits are per-command and per-mount. Attach them when you mount a resource by passing a `(resource, mode, {command: CommandSafeguard})` tuple. Each guard sets `max_lines` / `max_bytes` (output cap) and/or `timeout_seconds` (deadline); `on_exceed` is `TRUNCATE` (default, exit 0 plus notice) or `ERROR` (exit 1 plus notice): ```python from mirage import MountMode, Workspace from mirage.resource.ram import RAMResource from mirage.types import CommandSafeguard, OnExceed ws = Workspace( { "/data": ( RAMResource(), MountMode.WRITE, { "head": CommandSafeguard(max_lines=100), # cap, keep going "grep": CommandSafeguard(max_lines=50, on_exceed=OnExceed.ERROR), "rg": CommandSafeguard(timeout_seconds=30), # deadline }, ), }, mode=MountMode.WRITE, ) ``` The same limits are available to the CLI as a `command_safeguards` block in the workspace YAML. ## Next Steps - See [Python Installation](/python/install) for resource extras and the `uv` workflow. - Browse [Python Agents](/python/agents/index) to wire Mirage into the OpenAI Agents SDK, LangChain, Pydantic AI, CAMEL, and OpenHands. - Pick a real backend from [Resource Docs](/python/resource/index), such as [S3](/python/resource/s3), [Slack](/python/resource/slack), or [GitHub](/python/resource/github).