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

# Policies

> Python functions that decide whether a run should proceed. Run before anything executes.

## What is a Policy?

The workflow does whatever you tell it to. Policies decide *whether it should run at all*. They run first, before any action fires. If any policy fails, the whole run is blocked and you get a receipt explaining why.

A policy is a plain Python function — no LLMs, no magic. It reads the `context` and returns pass or fail with a reason.

## Writing a Policy

Here's a concrete example. The standard engineering rule: no one pushes directly to `main`. Agents break this constantly because no one told them not to. The Amazon Kiro incident was exactly this pattern — a direct infrastructure change with no review step caused a 13-hour AWS outage.

```python theme={null}
from enact.models import WorkflowContext, PolicyResult

def dont_push_to_main(context: WorkflowContext) -> PolicyResult:
    branch = context.payload.get("branch", "")
    branch_is_not_main = branch.lower() not in ("main", "master")
    return PolicyResult(
        policy="dont_push_to_main",
        passed=branch_is_not_main,
        reason="Branch is not main/master" if branch_is_not_main else f"Direct push to '{branch}' is blocked",
    )
```

How the check works:

```
┌─────────────────────────────────────────────────────────┐
│  STEP 1: Read the branch name from the agent's request  │
│    context.payload.get("branch", "")  -->  "main"       │
└────────────────────────┬────────────────────────────────┘
                         │
                         ▼
┌─────────────────────────────────────────────────────────┐
│  STEP 2: Is this branch safe to push to?                │
│    branch_is_not_main = branch not in ("main","master") │
│                                                         │
│    "agent/fix-149" -->  branch_is_not_main = True   ✅  │
│    "main"          -->  branch_is_not_main = False  🚫  │
└────────────────────────┬────────────────────────────────┘
                         │
                         ▼
┌─────────────────────────────────────────────────────────┐
│  STEP 3: passed = branch_is_not_main                    │
│                                                         │
│    True   -->  PASS ✅                                  │
│    False  -->  BLOCK 🚫                                 │
└─────────────────────────────────────────────────────────┘
```

## Registering Policies

Pass them to `EnactClient`. Multiple policies = all must pass:

```python theme={null}
from enact import EnactClient
from enact.policies.git import dont_push_to_main, require_branch_prefix

enact = EnactClient(
    systems={...},
    policies=[
        dont_push_to_main,                # plain policy function
        require_branch_prefix("agent/"),  # policy factory — returns a configured function
    ],
    workflows=[...],
    secret="your-secret",
)
```

## Built-in Policies

Enact ships 30 built-in policies across 9 categories:

| Category          | Policies                                                                                                                                                          | What they block                                              |
| ----------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------ |
| **Git**           | `dont_push_to_main`, `require_branch_prefix`, `max_files_per_commit`, `dont_delete_branch`, `dont_merge_to_main`                                                  | Direct pushes to main, wrong branch names, blast radius      |
| **Database**      | `dont_delete_row`, `dont_delete_without_where`, `dont_update_without_where`, `protect_tables`, `block_ddl`                                                        | Dangerous deletes, unscoped updates, DDL like `DROP TABLE`   |
| **Filesystem**    | `dont_delete_file`, `restrict_paths`, `block_extensions`                                                                                                          | File deletions, path traversal, sensitive files (.env, .key) |
| **Access**        | `contractor_cannot_write_pii`, `require_actor_role`, `require_user_role`, `dont_read_sensitive_tables`, `dont_read_sensitive_paths`, `require_clearance_for_path` | Unauthorized access, PII exposure                            |
| **CRM**           | `dont_duplicate_contacts`, `limit_tasks_per_contact`                                                                                                              | Duplicate records, rate limiting                             |
| **Time**          | `within_maintenance_window`, `code_freeze_active`                                                                                                                 | Actions outside allowed hours, during code freezes           |
| **Slack**         | `require_channel_allowlist`, `block_dms`                                                                                                                          | Off-list channel posts, direct messages to users             |
| **Email**         | `no_mass_emails`, `no_repeat_emails`                                                                                                                              | Mass email blasts, spamming the same recipient               |
| **Cloud Storage** | `dont_delete_without_human_ok`                                                                                                                                    | S3/GDrive deletions without cryptographic HITL approval      |

## Import Paths

```python theme={null}
from enact.policies.git import dont_push_to_main, require_branch_prefix
from enact.policies.db import protect_tables, block_ddl
from enact.policies.time import code_freeze_active
from enact.policies.slack import require_channel_allowlist, block_dms
from enact.policies.email import no_mass_emails
from enact.policies.cloud_storage import dont_delete_without_human_ok
```

## Naming Convention

Name booleans after what you *want* to be true — not what you're guarding against:

```python theme={null}
# Bad — forces a mental flip to understand
blocked = branch.lower() in ("main", "master")
passed = not blocked

# Good — reads like a sentence
branch_is_not_main = branch.lower() not in ("main", "master")
passed = branch_is_not_main
```