> ## Documentation Index
> Fetch the complete documentation index at: https://ibm-llm-runtime-aaf3a78b.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# mellea.stdlib.tools.execution_policy

> Capability policy, artifact model, and compatibility matrix for code execution environments.

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Capability policy, artifact model, and compatibility matrix for code execution environments.

Four execution tiers are available, selectable by intent rather than by class name:

* `"local_unsafe"`  — subprocess in the current Python env, no policy applied.
* `"local"`         — subprocess in the current Python env, policy declared and partially enforced.
* `"docker_unsafe"` — Docker-isolated execution via llm-sandbox, no policy applied.
* `"docker"`        — Docker-isolated execution via llm-sandbox, policy declared and partially enforced.

`CapabilityPolicy` declares what a code execution environment is *allowed* to do.
Enforcement is honest: each capability has a companion `ENFORCED_*` class attribute
indicating whether the declared value is actively enforced at runtime or is informational
only.

`Artifact` represents a file produced by execution and exported from the environment.

`COMPATIBILITY_MATRIX` records which capabilities each tier supports.

## Classes

<div className="w-full h-px bg-gray-200 dark:bg-gray-700 my-4" />

### <span className="ml-2 inline-flex items-center rounded-full px-2 py-1 text-[0.7rem] font-bold tracking-wide bg-[#4ADE8033]/20 text-[#15803D]">CLASS</span> `Artifact` <sup><a href="https://github.com/generative-computing/mellea/blob/v0.7.0.dev0/mellea/stdlib/tools/execution_policy.py#L28" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

A file produced by code execution and exported from the execution environment.

**Args:**

* `path`: Absolute path on the host where the artifact was written.
* `size_bytes`: File size in bytes, or `None` if unknown.
* `content_type`: MIME type or informal label (e.g. `"text/csv"`,
  `"image/png"`), or `None` if undetermined.

<div className="w-full h-px bg-gray-200 dark:bg-gray-700 my-4" />

### <span className="ml-2 inline-flex items-center rounded-full px-2 py-1 text-[0.7rem] font-bold tracking-wide bg-[#4ADE8033]/20 text-[#15803D]">CLASS</span> `CapabilityPolicy` <sup><a href="https://github.com/generative-computing/mellea/blob/v0.7.0.dev0/mellea/stdlib/tools/execution_policy.py#L44" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

Declared capabilities and resource limits for a code execution environment.

The enforcement gap — the difference between what is *declared* and what is
*actively enforced at runtime* — is made explicit through per-field
`ENFORCED_*` class attributes.  Callers and UX layers can read these to
decide whether to prompt the user ("allow once / allow always") or display
a warning.

**Args:**

* `filesystem_read_roots`: Host paths the environment may
  read.  `None` means unrestricted.  Declared only — not enforced.
* `filesystem_write_roots`: Host paths the environment may
  write.  `None` means unrestricted.  Declared only — not enforced.
* `network_access`: Whether outbound network connections are allowed.
  Defaults to `False`.  Declared only — not enforced.
* `package_installation`: Whether the environment may install packages.
  Declared only — not enforced.
* `subprocess_execution`: Whether spawning child processes is allowed.
  Declared only — not enforced.
* `env_var_access`: Whether environment variables are readable.
  Declared only — not enforced.
* `timeout`: Wall-clock seconds before execution is killed.  Enforced.
* `stdout_max_bytes`: Truncate stdout to this byte count; `None`
  disables truncation.  Enforced.
* `stderr_max_bytes`: Truncate stderr to this byte count; `None`
  disables truncation.  Enforced.
* `artifact_export_paths`: Paths inside the container/environment
  to copy out after execution as `Artifact` objects.  Enforced.
* `packages`: Python packages to install (via `pip install`) before
  execution.  Enforced — the runtime installs packages prior to executing
  user code and aborts with a skipped `ExecutionResult` if installation
  fails.  Failed packages are not retried on subsequent calls (clear
  `_failed_packages` on the environment to force a retry).  Local tiers
  use `uv pip install` / `python -m pip`; Docker tiers run
  `pip install` inside the container.  Defaults to `[]`.

<div className="h-8" />

**Methods:**

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#### <span className="ml-2 inline-flex items-center rounded-full px-2 py-1 text-[0.7rem] font-bold tracking-wide bg-[#3064E3]/20 text-[#1D4ED8]">FUNC</span> `unenforced_capabilities` <sup><a href="https://github.com/generative-computing/mellea/blob/v0.7.0.dev0/mellea/stdlib/tools/execution_policy.py#L108" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python theme={null}
unenforced_capabilities(self) -> list[str]
```

Return capability names that are declared but not enforced at runtime.

**Returns:**

* list\[str]: Field names whose declared values are informational only.

<div className="w-full h-px bg-gray-200 dark:bg-gray-700 my-4" />

#### <span className="ml-2 inline-flex items-center rounded-full px-2 py-1 text-[0.7rem] font-bold tracking-wide bg-[#3064E3]/20 text-[#1D4ED8]">FUNC</span> `enforced_capabilities` <sup><a href="https://github.com/generative-computing/mellea/blob/v0.7.0.dev0/mellea/stdlib/tools/execution_policy.py#L120" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python theme={null}
enforced_capabilities(self) -> list[str]
```

Return capability names that are actively enforced at runtime.

**Returns:**

* list\[str]: Field names whose declared values are honoured by the runtime.

<div className="w-full h-px bg-gray-200 dark:bg-gray-700 my-4" />