Allow blocks in deployment params

src/prefect/blocks/core.py

@@ -2,6 +2,7 @@
 import html
 import inspect
 import sys
+import uuid
 import warnings
 from abc import ABC
 from functools import partial
@@ -272,6 +273,15 @@ class Block(BaseModel, ABC):
     )
 
     def __init__(self, *args, **kwargs):
+        block_document_id = kwargs.pop("$ref", None)
+        if block_document_id:
+            block_document, block_document_name = self._get_block_document_by_id(
+                block_document_id
+            )
+            kwargs = {
+                **block_document.data,
+                **kwargs,
+            }
         super().__init__(*args, **kwargs)
         self.block_initialization()
 
@@ -790,6 +800,33 @@ async def _get_block_document(
 
         return block_document, block_document_name
 
+    @classmethod
+    @sync_compatible
+    @inject_client
+    async def _get_block_document_by_id(
+        cls,
+        block_document_id: Union[str, uuid.UUID],
+        client: Optional["PrefectClient"] = None,
+    ):
+        if isinstance(block_document_id, str):
+            try:
+                block_document_id = UUID(block_document_id)
+            except ValueError as e:
+                raise ValueError(
+                    f"Block document ID {block_document_id!r} is not a valid UUID"
+                ) from e
+
+        try:
+            block_document = await client.read_block_document(
+                block_document_id=block_document_id
+            )
+        except prefect.exceptions.ObjectNotFound as e:
+            raise ValueError(
+                f"Unable to find block document with ID {block_document_id!r}"
+            ) from e
+
+        return block_document, block_document.name
+
     @classmethod
     @sync_compatible
     @inject_client

src/prefect/utilities/schema_tools/validation.py

@@ -253,5 +253,24 @@ def preprocess_schema(
                 process_properties(
                     definition["properties"], required_fields, allow_none_with_default
                 )
+            # Allow block types to be referenced by their id
+            if "block_type_slug" in definition:
+                schema["definitions"][definition["title"]] = {
+                    "oneOf": [
+                        definition,
+                        {
+                            "type": "object",
+                            "properties": {
+                                "$ref": {
+                                    "type": "string",
+                                    "format": "uuid",
+                                },
+                            },
+                            "required": [
+                                "$ref",
+                            ],
+                        },
+                    ]
+                }
 
     return schema