feat: generate types.py from genkit-schema.json using datamodel-codegen

#1807

    ISSUE: #1807

    CHANGELOG:
    - [ ] Add a bin/generate_schema_types script that generates the Pydantic
      types.py module.
    - [ ] Update the pre-commit hooks to ensure this file gets regenerated
      routinely.
    - [ ] Remove timestamp to ensure we do not treat a file with identical
      content differently preventing the hassles of updating this file per
    commit.

py/bin/generate_schema_types

@@ -0,0 +1,33 @@
+#!/usr/bin/env bash
+#
+# Copyright 2025 Google LLC
+# SPDX-License-Identifier: Apache-2.0
+
+set -euo pipefail
+
+TOP_DIR=$(git rev-parse --show-toplevel)
+
+uv run --directory "$TOP_DIR/py" \
+  datamodel-codegen \
+  --collapse-root-models \
+  --disable-timestamp \
+  --enable-version-header \
+  --input "$TOP_DIR/genkit-tools/genkit-schema.json" \
+  --input-file-type jsonschema \
+  --output-model-type pydantic_v2.BaseModel \
+  --output "$TOP_DIR/py/packages/genkit/src/genkit/core/types.py" \
+  --target-python-version 3.12 \
+  --use-schema-description \
+  --use-standard-collections \
+  --use-union-operator
+
+addlicense \
+  -c "Google LLC" \
+  -s=only \
+  "$TOP_DIR/py/packages/genkit/src/genkit/core/types.py"
+
+uv run --directory "$TOP_DIR/py" \
+  ruff check --fix "${TOP_DIR}/py/packages/genkit/src/genkit/core/types.py"
+
+uv run --directory "$TOP_DIR/py" \
+  ruff format "${TOP_DIR}/py/packages/genkit/src/genkit/core/types.py"

py/captainhook.json

@@ -33,6 +33,9 @@
         {
           "run": "pnpm i --frozen-lockfile"
         },
+        {
+          "run": "py/bin/generate_schema_types"
+        },
         {
           "run": "py/bin/fmt"
         },
@@ -81,6 +84,9 @@
         {
           "run": "pnpm i --frozen-lockfile"
         },
+        {
+          "run": "py/bin/generate_schema_types"
+        },
         {
           "run": "py/bin/fmt"
         },