> ## Documentation Index
> Fetch the complete documentation index at: https://docs.nanny.run/llms.txt
> Use this file to discover all available pages before exploring further.

# nanny run

> Run a command under Nanny enforcement.

Spawns a child process under full Nanny enforcement. Reads `nanny.toml` from the current directory and kills the process the moment any limit is crossed.

```bash theme={null}
nanny run [OPTIONS] [-- ARGS...]
```

***

## Examples

```bash theme={null}
# Run with base [limits] (reads [start].cmd from nanny.toml)
nanny run

# Run with a named limit set
nanny run --limits=researcher
```

***

## Options

| Flag              | Type   | Default        | Description                                                             |
| ----------------- | ------ | -------------- | ----------------------------------------------------------------------- |
| `--limits=<name>` | string | —              | Activate a named limit set from `nanny.toml`. Inherits from `[limits]`. |
| `--config=<path>` | path   | `./nanny.toml` | Path to config file.                                                    |

***

## Exit codes

| Code | Meaning                                                                            |
| ---- | ---------------------------------------------------------------------------------- |
| `0`  | Process exited cleanly (`AgentCompleted`)                                          |
| `1`  | Nanny stopped the process, a spawn failure occurred, or an internal error occurred |

***

## Stderr

When Nanny stops a process it prints the reason to stderr:

```
nanny: stopped — TimeoutExpired
nanny: stopped — BudgetExhausted
nanny: stopped — MaxStepsReached
nanny: stopped — ToolDenied
nanny: stopped — RuleDenied
```

This message is separate from the structured event log, which goes to stdout (or a configured file).

***

## Event log

Every run emits [NDJSON events](/v0.4/concepts/event-log) to stdout. `ExecutionStarted` is always first; `ExecutionStopped` is always last:

```json theme={null}
{"event":"ExecutionStarted","ts":1711234567000,"limits":{"steps":100,"tokens":1000,"timeout":30000},"limits_set":"[limits]","command":"python agent.py"}
{"event":"ToolAllowed","ts":1711234567120,"tool":"http_get"}
{"event":"StepCompleted","ts":1711234567800,"step":1}
{"event":"ExecutionStopped","ts":1711234572000,"reason":"BudgetExhausted","steps":12,"tokens_spent":1000,"elapsed_ms":5000}
```

Pipe to a file to keep your agent's own output separate:

```bash theme={null}
nanny run > nanny.log
```

***

For per-function governance (marking individual tools and rules in code), see the [Rust SDK guide](/v0.4/guides/rust-sdk) or [Python SDK guide](/v0.4/guides/python-sdk).