chore: import upstream snapshot with attribution

entity/configs/node/literal.py

@@ -0,0 +1,69 @@
+"""Configuration for literal nodes."""
+
+from dataclasses import dataclass
+from typing import Mapping, Any
+
+from entity.configs.base import (
+    BaseConfig,
+    ConfigError,
+    ConfigFieldSpec,
+    EnumOption,
+    optional_str,
+    require_mapping,
+    require_str,
+)
+from entity.messages import MessageRole
+
+
+@dataclass
+class LiteralNodeConfig(BaseConfig):
+    """Config describing the literal payload emitted by the node."""
+
+    content: str = ""
+    role: MessageRole = MessageRole.USER
+
+    @classmethod
+    def from_dict(cls, data: Mapping[str, Any], *, path: str) -> "LiteralNodeConfig":
+        mapping = require_mapping(data, path)
+        content = require_str(mapping, "content", path)
+        if not content:
+            raise ConfigError("content cannot be empty", f"{path}.content")
+
+        role_value = optional_str(mapping, "role", path)
+        role = MessageRole.USER
+        if role_value:
+            normalized = role_value.strip().lower()
+            if normalized not in (MessageRole.USER.value, MessageRole.ASSISTANT.value):
+                raise ConfigError("role must be 'user' or 'assistant'", f"{path}.role")
+            role = MessageRole(normalized)
+
+        return cls(content=content, role=role, path=path)
+
+    def validate(self) -> None:
+        if not self.content:
+            raise ConfigError("content cannot be empty", f"{self.path}.content")
+        if self.role not in (MessageRole.USER, MessageRole.ASSISTANT):
+            raise ConfigError("role must be 'user' or 'assistant'", f"{self.path}.role")
+
+    FIELD_SPECS = {
+        "content": ConfigFieldSpec(
+            name="content",
+            display_name="Literal Content",
+            type_hint="text",
+            required=True,
+            description="Plain text emitted whenever the node executes.",
+        ),
+        "role": ConfigFieldSpec(
+            name="role",
+            display_name="Message Role",
+            type_hint="str",
+            required=False,
+            default=MessageRole.USER.value,
+            enum=[MessageRole.USER.value, MessageRole.ASSISTANT.value],
+            enum_options=[
+                EnumOption(value=MessageRole.USER.value, label="user"),
+                EnumOption(value=MessageRole.ASSISTANT.value, label="assistant"),
+            ],
+            description="Select whether the literal message should appear as a user or assistant entry.",
+        ),
+    }