Development and Custom Transforms

Input Constraints

Modified on: Tue, 14 Jul, 2026 at 11:36 AM

Input constraints control which entities can trigger a transform. They're evaluated by the Maltego client before showing the transform to users, so users only see transforms that apply to their selection.

Basic Usage

Add constraints via the input_constraint parameter in @register_transform:

from maltego.server import register_transform
from maltego.model.input_constraints import EntityTypeConstraint


@register_transform(
    display_name="Domain Transform",
    transform_set="My Transforms",
    input_constraint=EntityTypeConstraint(entity_type="maltego.Domain")
)
async def domain_only(entity):
    # Only runs on Domain entities
    ...

Entity Type Constraints

Single Entity Type

from maltego.model.input_constraints import EntityTypeConstraint

input_constraint=EntityTypeConstraint(entity_type="maltego.Domain")

Multiple Entity Types (OR)

from maltego.model.input_constraints import EntitySatisfiesAny, EntityTypeConstraint

input_constraint=EntitySatisfiesAny(
    constraints=[
        EntityTypeConstraint(entity_type="maltego.Domain"),
        EntityTypeConstraint(entity_type="maltego.IPv4Address"),
    ]
)

Property Constraints

Property Exists

from maltego.model.input_constraints import (
    EntityHasPropertySatisfying,
    PropertyNameEquals
)

# Entity must have an 'email' property
input_constraint=EntityHasPropertySatisfying(
    constraint=PropertyNameEquals(value="email")
)

Property Value Equals

from maltego.model.input_constraints import (
    EntityHasPropertySatisfying,
    PropertySatisfiesAll,
    PropertyNameEquals,
    PropertyValueEquals
)

# Property 'status' must equal 'active'
input_constraint=EntityHasPropertySatisfying(
    constraint=PropertySatisfiesAll(
        constraints=[
            PropertyNameEquals(value="status"),
            PropertyValueEquals(value="active", ignore_case=True),
        ]
    )
)

Property String Matching

from maltego.model.input_constraints import (
    EntityHasPropertySatisfying,
    PropertySatisfiesAll,
    PropertyNameEquals,
    PropertyValueStringMatch,
    ConstraintStringMatchType
)

# Property 'domain' starts with 'www.'
input_constraint=EntityHasPropertySatisfying(
    constraint=PropertySatisfiesAll(
        constraints=[
            PropertyNameEquals(value="domain"),
            PropertyValueStringMatch(
                value="www.",
                match_type=ConstraintStringMatchType.STARTSWITH,
                ignore_case=True
            ),
        ]
    )
)

String Match Types:

Type	Description
`STARTSWITH`	Value starts with pattern
`ENDSWITH`	Value ends with pattern
`CONTAINS`	Value contains pattern

Property Regex Matching

from maltego.model.input_constraints import (
    EntityHasPropertySatisfying,
    PropertyValueMatchesRegex
)

# Property value matches email pattern
input_constraint=EntityHasPropertySatisfying(
    constraint=PropertyValueMatchesRegex(
        regex=r"^[\w.-]+@[\w.-]+\.\w+$"
    )
)

Property Type Checking

from maltego.model.input_constraints import (
    EntityHasPropertySatisfying,
    PropertyTypeEquals
)

# Entity has a DATE-type property
input_constraint=EntityHasPropertySatisfying(
    constraint=PropertyTypeEquals(value="DATE")
)

Property Types: STRING, INT, DOUBLE, BOOLEAN, DATE, DATETIME, DATETIME_RANGE

Combining Constraints

AND Logic (All Must Match)

from maltego.model.input_constraints import EntitySatisfiesAll

input_constraint=EntitySatisfiesAll(
    constraints=[
        EntityTypeConstraint(entity_type="maltego.Domain"),
        EntityHasPropertySatisfying(
            constraint=PropertyNameEquals(value="registrar")
        ),
    ]
)

OR Logic (Any Can Match)

from maltego.model.input_constraints import EntitySatisfiesAny

input_constraint=EntitySatisfiesAny(
    constraints=[
        EntityTypeConstraint(entity_type="maltego.Domain"),
        EntityTypeConstraint(entity_type="maltego.URL"),
    ]
)

NOT Logic (None Should Match)

from maltego.model.input_constraints import EntitySatisfiesNone

# Entity does NOT have status='inactive'
input_constraint=EntitySatisfiesNone(
    constraints=[
        EntityHasPropertySatisfying(
            constraint=PropertySatisfiesAll(
                constraints=[
                    PropertyNameEquals(value="status"),
                    PropertyValueEquals(value="inactive"),
                ]
            )
        ),
    ]
)

Complex Examples

Entity Type + Property Value

# Domain entities where registrar is "GoDaddy"
input_constraint=EntitySatisfiesAll(
    constraints=[
        EntityTypeConstraint(entity_type="maltego.Domain"),
        EntityHasPropertySatisfying(
            constraint=PropertySatisfiesAll(
                constraints=[
                    PropertyNameEquals(value="registrar"),
                    PropertyValueEquals(value="GoDaddy", ignore_case=True),
                ]
            )
        ),
    ]
)

Multiple Types + Property Condition

# (Domain OR Person) with email ending in @company.com
input_constraint=EntitySatisfiesAll(
    constraints=[
        EntitySatisfiesAny(
            constraints=[
                EntityTypeConstraint(entity_type="maltego.Domain"),
                EntityTypeConstraint(entity_type="maltego.Person"),
            ]
        ),
        EntityHasPropertySatisfying(
            constraint=PropertySatisfiesAll(
                constraints=[
                    PropertyNameEquals(value="email"),
                    PropertyValueStringMatch(
                        value="@company.com",
                        match_type=ConstraintStringMatchType.ENDSWITH,
                        ignore_case=True
                    ),
                ]
            )
        ),
    ]
)

Excluding Certain Values

# Domains that are NOT .gov or .mil
input_constraint=EntitySatisfiesAll(
    constraints=[
        EntityTypeConstraint(entity_type="maltego.Domain"),
        EntitySatisfiesNone(
            constraints=[
                EntityHasPropertySatisfying(
                    constraint=PropertyValueStringMatch(
                        value=".gov",
                        match_type=ConstraintStringMatchType.ENDSWITH
                    )
                ),
                EntityHasPropertySatisfying(
                    constraint=PropertyValueStringMatch(
                        value=".mil",
                        match_type=ConstraintStringMatchType.ENDSWITH
                    )
                ),
            ]
        ),
    ]
)

Complete Example

Run maltego-transforms start my_project to create a new project from the template. See transforms/input_constraints_example.py for runnable examples of all constraint types covered in this guide.

Constraint Reference

Entity-Level Constraints

Constraint	Description
`EntityTypeConstraint`	Match specific entity type
`EntitySatisfiesAll`	All constraints must match (AND)
`EntitySatisfiesAny`	At least one constraint must match (OR)
`EntitySatisfiesNone`	No constraints must match (NOT)
`EntityHasPropertySatisfying`	Entity has property matching constraint

Property-Level Constraints

Constraint	Description
`PropertyNameEquals`	Property name matches
`PropertyDisplayNameEquals`	Property display name matches
`PropertyValueEquals`	Property value exact match
`PropertyValueStringMatch`	Property value string pattern
`PropertyValueMatchesRegex`	Property value regex match
`PropertyTypeEquals`	Property type matches
`PropertySatisfiesAll`	All property constraints match (AND)
`PropertySatisfiesAny`	At least one property constraint matches (OR)

Best Practices

Be specific - Narrow constraints reduce clutter in transform menus
Use entity types first - They're the fastest filter
Combine with property checks - For precise targeting
Test constraints - Ensure transforms appear when expected
Document requirements - Help users understand when transforms apply