FEAT: Supporting Converter Configuration on REST API

pyrit/backend/models/__init__.py

@@ -23,6 +23,7 @@
         AttackSummary,
         ConversationMessagesResponse,
         ConversationSummary,
+        ConverterConfigurationRequest,
         ConverterOptionsResponse,
         CreateAttackRequest,
         CreateAttackResponse,
@@ -74,6 +75,7 @@
     "UpdateMainConversationResponse": "pyrit.backend.models.attacks",
     "ConversationMessagesResponse": "pyrit.backend.models.attacks",
     "ConversationSummary": "pyrit.backend.models.attacks",
+    "ConverterConfigurationRequest": "pyrit.backend.models.attacks",
     "ConverterOptionsResponse": "pyrit.backend.models.attacks",
     "CreateAttackRequest": "pyrit.backend.models.attacks",
     "CreateAttackResponse": "pyrit.backend.models.attacks",

pyrit/backend/models/attacks.py

@@ -10,9 +10,9 @@
 
 import uuid
 from datetime import datetime, timezone
-from typing import Any, Literal, cast
+from typing import Annotated, Any, Literal, cast
 
-from pydantic import BaseModel, Field, computed_field, field_serializer
+from pydantic import BaseModel, Field, computed_field, field_serializer, model_validator
 
 from pyrit.backend.models._media import build_filename, infer_mime_type
 from pyrit.backend.models.common import PaginationInfo
@@ -22,6 +22,7 @@
     ConversationReference,
     Message,
     MessagePiece,
+    PromptDataType,
     Score,
 )
 
@@ -472,6 +473,26 @@ class UpdateMainConversationResponse(BaseModel):
 # ============================================================================
 
 
+class ConverterConfigurationRequest(BaseModel):
+    """Registry-backed converter configuration for one ordered pipeline."""
+
+    converter_ids: list[str] = Field(
+        ...,
+        min_length=1,
+        description="Converter instance IDs to apply in order.",
+    )
+    indexes_to_apply: list[Annotated[int, Field(ge=0)]] | None = Field(
+        None,
+        min_length=1,
+        description="Zero-based message piece indexes to which this pipeline applies. Defaults to all indexes.",
+    )
+    prompt_data_types_to_apply: list[PromptDataType] | None = Field(
+        None,
+        min_length=1,
+        description="Prompt data types to which this pipeline applies. Defaults to all data types.",
+    )
+
+
 class AddMessageRequest(BaseModel):
     """
     Request to add a message to an attack.
@@ -492,7 +513,18 @@ class AddMessageRequest(BaseModel):
         description="Target registry name. Required when send=True so the backend knows which target to use.",
     )
     converter_ids: list[str] | None = Field(
-        None, description="Converter instance IDs to apply (overrides attack-level)"
+        None,
+        description="Deprecated global request converter pipeline. Use request_converter_configurations instead.",
+    )
+    request_converter_configurations: list[ConverterConfigurationRequest] | None = Field(
+        None,
+        min_length=1,
+        description="Ordered registry-backed converter pipelines to apply to the request.",
+    )
+    response_converter_configurations: list[ConverterConfigurationRequest] | None = Field(
+        None,
+        min_length=1,
+        description="Ordered registry-backed converter pipelines to apply to the response.",
     )
     target_conversation_id: str = Field(
         ...,
@@ -505,6 +537,43 @@ class AddMessageRequest(BaseModel):
         "When present, the operator must match the attack result's operator.",
     )
 
+    @model_validator(mode="after")
+    def _validate_converter_configurations(self) -> "AddMessageRequest":
+        """
+        Validate converter configuration combinations and request indexes.
+
+        Returns:
+            AddMessageRequest: The validated request.
+
+        Raises:
+            ValueError: If converter fields conflict, cannot run, or contain an out-of-range request index.
+        """
+        if self.converter_ids is not None and self.request_converter_configurations is not None:
+            raise ValueError("converter_ids and request_converter_configurations cannot both be provided")
+
+        has_converter_configurations = any(
+            configurations is not None
+            for configurations in (
+                self.converter_ids,
+                self.request_converter_configurations,
+                self.response_converter_configurations,
+            )
+        )
+        if not self.send and has_converter_configurations:
+            raise ValueError("Converter configurations require send=True")
+
+        piece_count = len(self.pieces)
+        for configuration in self.request_converter_configurations or []:
+            if configuration.indexes_to_apply is None:
+                continue
+            invalid_indexes = [index for index in configuration.indexes_to_apply if index >= piece_count]
+            if invalid_indexes:
+                raise ValueError(
+                    f"Request converter indexes {invalid_indexes} are out of range for {piece_count} message pieces"
+                )
+
+        return self
+
 
 class AddMessageResponse(BaseModel):
     """

pyrit/backend/routes/attacks.py

@@ -449,10 +449,10 @@ async def add_message(  # pyrit-async-suffix-exempt
     If send=False, just stores the message in memory without sending (useful for
     system messages, context injection, or replaying assistant responses).
 
-    Converters can be specified at three levels (in priority order):
-    1. request.converter_ids - per-message converter instances
-    2. request.converters - inline converter definitions
-    3. attack.converter_ids - attack-level defaults
+    Request and response converters can be supplied as ordered, registry-backed
+    configurations. Each configuration can target message piece indexes, prompt
+    data types, or both. The global ``converter_ids`` request pipeline remains
+    available for compatibility but is deprecated.
 
     Returns:
         AddMessageResponse: Updated attack with new message(s).