> ## Documentation Index
> Fetch the complete documentation index at: https://conductorone-luisinasantos-sync-coupa-v0-1-13-docs.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# CEL expressions

> Common Expression Language reference for baton-http and baton-sql data transformation.

Both meta-connectors use the Common Expression Language (CEL) for data transformation. CEL is a simple, fast, and secure expression language - a safer alternative to embedding arbitrary code in your config.

## Basic field mapping

```yaml theme={null}
map:
  id: ".id"                                           # Direct field access
  display_name: ".first_name + ' ' + .last_name"      # String concatenation
  status: ".is_active ? 'enabled' : 'disabled'"       # Ternary
```

## Available functions

| Function | Purpose | Example |
| - | - | - |
| `lowercase()` | Convert to lowercase | `lowercase(.email)` |
| `uppercase()` | Convert to uppercase | `uppercase(.code)` |
| `titlecase()` | Title case | `titlecase(.name)` |
| `trim()` | Remove whitespace | `trim(.value)` |
| `match()` | Regex matching | `match(.email, ".*@corp\\.com")` |
| `extract()` | Extract regex group | `extract(.urn, "user-([0-9]+)")` |
| `replace()` | String replacement | `replace(.name, {"old": "_", "new": "-"})` |
| `get()` | Get with default | `get(.optional, "default")` |
| `has()` | Check field exists | `has(input.employee_id)` |
| `parse_json()` | Parse JSON string | `parse_json(.metadata).type` |
| `json_path()` | Extract from JSON | `json_path(.data, "user.name")` |

## Context variables

Available variables depend on context:

| Variable | Available in | Purpose |
| - | - | - |
| `item` or `.column` | List/Grants | Current row/item |
| `resource` | Grants, Provisioning | Current resource |
| `principal` | Provisioning | User being granted/revoked |
| `entitlement` | Provisioning | Entitlement being modified |
| `input` | Account creation | User-provided form values |
| `password` | Account creation | Generated password |

## Common patterns

### Conditional field mapping

```yaml theme={null}
account_type: ".type == 'employee' ? 'human' : 'service'"
```

### Null handling

```yaml theme={null}
last_login: ".last_login != null ? string(.last_login) : ''"
```

### String operations

```yaml theme={null}
# Lowercase email
email: "lowercase(.email)"

# Build full name
display_name: ".first_name + ' ' + .last_name"

# Extract username from email
username: "extract(.email, '([^@]+)@.*')"
```

### Type conversion

```yaml theme={null}
# Convert numeric ID to string
id: "string(.numeric_id)"
```

### Field existence check

```yaml theme={null}
# Use optional field with fallback
department: "has(input.department) ? input.department : 'Unknown'"
```

### Skip conditions in grants

```yaml theme={null}
grants:
  - query: "SELECT * FROM role_members WHERE role_id = ?<role_id>"
    map:
      - skip_if: ".user_type == 'system'"    # Skip system accounts
        principal_id: ".user_id"
        principal_type: "user"
        entitlement_id: "member"
```

## Quick reference

```yaml theme={null}
# Direct field access
".field_name"

# String concatenation
".first + ' ' + .last"

# Ternary
".active ? 'enabled' : 'disabled'"

# Null check
".value != null ? .value : 'default'"

# Type conversion
"string(.numeric_id)"

# Field existence check
"has(input.optional_field)"

# Lowercase/uppercase
"lowercase(.email)"
"uppercase(.code)"
```