feat: bundle-based schema sync + Sigstore verify + 4.0.0b1 on latest

.github/workflows/ci.yml

@@ -111,10 +111,13 @@ jobs:
         run: |
           VERSION=$(cat src/adcp/ADCP_VERSION)
           echo "ADCP_VERSION=$VERSION"
-          # Check if version contains pre-release identifiers (alpha, beta, rc)
-          if echo "$VERSION" | grep -qE '(alpha|beta|rc)'; then
+          # Skip regeneration + drift check for pre-release tags (alpha/beta/rc)
+          # and for `latest`, which is a moving dev snapshot — the committed
+          # generated types are frozen against the bundle we last synced, and
+          # CI's fresh sync against today's `latest.tgz` is expected to drift.
+          if echo "$VERSION" | grep -qE '(alpha|beta|rc)' || [ "$VERSION" = "latest" ]; then
             echo "is_prerelease=true" >> $GITHUB_OUTPUT
-            echo "Pre-release version detected - will skip schema sync (may not be publicly accessible)"
+            echo "Pre-release / latest version detected - will skip schema sync"
           else
             echo "is_prerelease=false" >> $GITHUB_OUTPUT
             echo "Stable version - will sync schemas from upstream"

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "adcp"
-version = "3.12.0"
+version = "4.0.0b1"
 description = "Official Python client for the Ad Context Protocol (AdCP)"
 authors = [
     {name = "AdCP Community", email = "maintainers@adcontextprotocol.org"}
@@ -14,7 +14,7 @@ requires-python = ">=3.10"
 license = {text = "Apache-2.0"}
 keywords = ["adcp", "mcp", "a2a", "protocol", "advertising"]
 classifiers = [
-    "Development Status :: 3 - Alpha",
+    "Development Status :: 4 - Beta",
     "Intended Audience :: Developers",
     "License :: OSI Approved :: Apache Software License",
     "Programming Language :: Python :: 3",
@@ -45,7 +45,10 @@ dev = [
     "mypy>=1.0.0",
     "black>=23.0.0",
     "ruff>=0.1.0",
-    "datamodel-code-generator[http]>=0.35.0",
+    # Pin to exact version: codegen's variant numbering (e.g. CreateMediaBuyResponse1 vs
+    # CreateMediaBuyResponse) shifts between versions, producing diff churn and breaking
+    # generated-code imports that reference specific suffixes.
+    "datamodel-code-generator[http]==0.56.1",
 ]
 docs = [
     "pdoc3>=0.10.0",
@@ -150,6 +153,6 @@ skips = ["B101"]  # Allow assert in code (we're not using -O optimization)
 
 [dependency-groups]
 dev = [
-    "datamodel-code-generator>=0.35.0",
+    "datamodel-code-generator==0.56.1",
     "pre-commit>=4.4.0",
 ]

schemas/cache/a2ui/bound-value.json

@@ -0,0 +1,80 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "title": "A2UI Bound Value",
+  "description": "A value that can be a literal or bound to a path in the data model",
+  "oneOf": [
+    {
+      "type": "object",
+      "description": "Literal string value",
+      "properties": {
+        "literalString": {
+          "type": "string",
+          "description": "Static string value"
+        }
+      },
+      "required": [
+        "literalString"
+      ],
+      "additionalProperties": false
+    },
+    {
+      "type": "object",
+      "description": "Literal number value",
+      "properties": {
+        "literalNumber": {
+          "type": "number",
+          "description": "Static number value"
+        }
+      },
+      "required": [
+        "literalNumber"
+      ],
+      "additionalProperties": false
+    },
+    {
+      "type": "object",
+      "description": "Literal boolean value",
+      "properties": {
+        "literalBoolean": {
+          "type": "boolean",
+          "description": "Static boolean value"
+        }
+      },
+      "required": [
+        "literalBoolean"
+      ],
+      "additionalProperties": false
+    },
+    {
+      "type": "object",
+      "description": "Path to data model value",
+      "properties": {
+        "path": {
+          "type": "string",
+          "description": "JSON pointer path to value in data model (e.g., '/products/0/title')"
+        }
+      },
+      "required": [
+        "path"
+      ],
+      "additionalProperties": false
+    },
+    {
+      "type": "object",
+      "description": "Literal with path binding (sets default and binds)",
+      "properties": {
+        "literalString": {
+          "type": "string"
+        },
+        "path": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "literalString",
+        "path"
+      ],
+      "additionalProperties": false
+    }
+  ]
+}