feat: add UV runtime support in manifest v0.4

Add UV as a new server type for Python extensions that use UV runtime
for dependency management instead of bundling dependencies.

Schema changes (v0.4):
- Add "uv" to server.type enum
- Make mcp_config optional (not needed for UV type)
- UV extensions rely on pyproject.toml for dependencies

Documentation:
- Add UV runtime section to MANIFEST.md explaining benefits and usage
- Update README.md to recommend UV runtime for Python
- Add complete hello-world-uv example

Benefits of UV runtime:
- Cross-platform support (Windows/macOS/Linux, Intel/ARM)
- Small bundle size (~100 KB vs 5-10 MB)
- Handles compiled dependencies portably
- No user Python installation required

Example manifest:
{
  "manifest_version": "0.4",
  "server": {
    "type": "uv",
    "entry_point": "src/server.py"
  }
}

Co-authored-by: Joan <joan@anthropic.com>

MANIFEST.md

@@ -1,7 +1,7 @@
 # MCPB Manifest.json Spec
 
 Current version: `0.3`
-Last updated: 2025-10-24
+Last updated: 2025-12-02
 
 ## Manifest Schema
 
@@ -398,6 +398,55 @@ The `server` object defines how to run the MCP server:
 
 ### Server Types
 
+Four server types are supported:
+
+- **`node`**: Node.js server with bundled dependencies
+- **`python`**: Python server with bundled dependencies
+- **`binary`**: Compiled executable
+- **`uv`**: Python server using UV runtime (experimental, v0.4+)
+
+### UV Runtime (Experimental, v0.4+)
+
+> **Note:** UV runtime support is experimental and may change in future versions.
+
+The `uv` server type enables cross-platform Python extensions without bundling dependencies. Instead, dependencies are declared in `pyproject.toml` and installed by the host application using UV.
+
+**Benefits:**
+- Cross-platform support (Windows, macOS, Linux; Intel, ARM)
+- Small bundle size (~100 KB vs 5-10 MB)
+- Handles compiled dependencies (pydantic, numpy, etc.)
+- No user Python installation required
+
+**Example:**
+```json
+{
+  "manifest_version": "0.4",
+  "server": {
+    "type": "uv",
+    "entry_point": "src/server.py"
+  }
+}
+```
+
+**Requirements:**
+- Must include `pyproject.toml` with dependencies
+- Must NOT include `server/lib/` or `server/venv/`
+- `mcp_config` is optional (host manages execution)
+
+**Package structure:**
+```
+extension.mcpb
+├── manifest.json       # server.type = "uv"
+├── pyproject.toml      # Dependencies
+├── .mcpbignore        # Exclude .venv, server/lib
+└── src/
+    └── server.py
+```
+
+See `examples/hello-world-uv` for a complete example.
+
+### Node, Python, and Binary Types
+
 1. **Python**: `server.type = "python"`
    - Requires `entry_point` to Python file
    - All dependencies must be bundled in the MCPB

README.md

@@ -109,12 +109,22 @@ bundle.mcpb (ZIP file)
 
 ### Bundling Dependencies
 
-**Python Bundles:**
+**UV Runtime (Experimental - v0.4+):**
 
+- Use `server.type = "uv"` in manifest
+- Include `pyproject.toml` with dependencies (no bundled packages needed)
+- Host application manages Python and dependencies automatically
+- Works cross-platform without user Python installation
+- See `examples/hello-world-uv`
+
+**Python Bundles (Traditional):**
+
+- Use `server.type = "python"` in manifest
 - Bundle all required packages in `server/lib/` directory
 - OR bundle a complete virtual environment in `server/venv/`
 - Use tools like `pip-tools`, `poetry`, or `pipenv` to create reproducible bundles
 - Set `PYTHONPATH` to include bundled packages via `mcp_config.env`
+- **Limitation**: Cannot portably bundle compiled dependencies (e.g., pydantic, which the MCP Python SDK requires)
 
 **Node.js Bundles:**
 

examples/hello-world-uv/.mcpbignore

@@ -0,0 +1,8 @@
+.venv/
+__pycache__/
+*.pyc
+.pytest_cache/
+.mypy_cache/
+*.egg-info/
+server/lib/
+server/venv/

examples/hello-world-uv/README.md

@@ -0,0 +1,62 @@
+# Hello World UV Runtime Example (Experimental)
+
+> **Note:** UV runtime support is experimental and may change in future versions.
+
+This example demonstrates a minimal MCP server using **UV runtime**.
+
+## What is UV Runtime?
+
+UV runtime lets Claude Desktop automatically manage Python and dependencies for your extension:
+- Downloads the correct Python version for the user's platform
+- Creates an isolated virtual environment
+- Installs dependencies from `pyproject.toml`
+- Works cross-platform (Windows, macOS, Linux) without user setup
+
+## Structure
+
+```
+hello-world-uv/
+├── manifest.json       # server.type = "uv"
+├── pyproject.toml      # Dependencies listed here
+├── .mcpbignore        # Exclude build artifacts
+└── src/
+    └── server.py       # MCP server implementation
+```
+
+## Key Differences from Python Runtime
+
+**UV Runtime** (this example):
+- `server.type = "uv"`
+- No bundled dependencies
+- No `mcp_config` needed
+- Small bundle size (~2 KB)
+- Works on any platform
+
+**Python Runtime** (traditional):
+- `server.type = "python"`
+- Must bundle dependencies in `server/lib/`
+- Requires `mcp_config` with PYTHONPATH
+- Larger bundle size
+- Only works with pure Python (no compiled deps)
+
+## Installing
+
+```bash
+mcpb pack
+```
+
+Install the generated `.mcpb` file in Claude Desktop.
+
+## Testing Locally
+
+```bash
+# Install dependencies
+uv sync
+
+# Run server
+uv run src/server.py
+```
+
+## Tools
+
+- **say_hello** - Greets a person by name

examples/hello-world-uv/manifest.json

@@ -0,0 +1,23 @@
+{
+  "manifest_version": "0.4",
+  "name": "hello-world-uv",
+  "display_name": "Hello World (UV Runtime)",
+  "version": "1.0.0",
+  "description": "Simple MCP server using UV runtime",
+  "author": {
+    "name": "Anthropic"
+  },
+  "icon": "icon.png",
+  "server": {
+    "type": "uv",
+    "entry_point": "src/server.py"
+  },
+  "compatibility": {
+    "platforms": ["darwin", "linux", "win32"],
+    "runtimes": {
+      "python": ">=3.10"
+    }
+  },
+  "keywords": ["example", "hello-world", "uv"],
+  "license": "MIT"
+}

examples/hello-world-uv/pyproject.toml

@@ -0,0 +1,8 @@
+[project]
+name = "hello-world-uv"
+version = "1.0.0"
+description = "Simple MCP server using UV runtime"
+requires-python = ">=3.10"
+dependencies = [
+    "mcp>=1.0.0",
+]

examples/hello-world-uv/src/server.py

@@ -0,0 +1,65 @@
+#!/usr/bin/env python3
+"""Hello World MCP server using UV runtime."""
+
+import asyncio
+from mcp.server.models import InitializationOptions
+import mcp.types as types
+from mcp.server import NotificationOptions, Server
+import mcp.server.stdio
+
+
+server = Server("hello-world-uv")
+
+
+@server.list_tools()
+async def handle_list_tools() -> list[types.Tool]:
+    """List available tools."""
+    return [
+        types.Tool(
+            name="say_hello",
+            description="Say hello to someone",
+            inputSchema={
+                "type": "object",
+                "properties": {
+                    "name": {
+                        "type": "string",
+                        "description": "Name to greet",
+                    }
+                },
+                "required": ["name"],
+            },
+        )
+    ]
+
+
+@server.call_tool()
+async def handle_call_tool(
+    name: str, arguments: dict | None
+) -> list[types.TextContent | types.ImageContent | types.EmbeddedResource]:
+    """Handle tool calls."""
+    if name == "say_hello":
+        person_name = arguments.get("name", "World") if arguments else "World"
+        return [types.TextContent(type="text", text=f"Hello, {person_name}!")]
+
+    raise ValueError(f"Unknown tool: {name}")
+
+
+async def main():
+    """Run the server."""
+    async with mcp.server.stdio.stdio_server() as (read_stream, write_stream):
+        await server.run(
+            read_stream,
+            write_stream,
+            InitializationOptions(
+                server_name="hello-world-uv",
+                server_version="1.0.0",
+                capabilities=server.get_capabilities(
+                    notification_options=NotificationOptions(),
+                    experimental_capabilities={},
+                ),
+            ),
+        )
+
+
+if __name__ == "__main__":
+    asyncio.run(main())

schemas/mcpb-manifest-v0.4.schema.json

@@ -0,0 +1,376 @@
+{
+  "type": "object",
+  "properties": {
+    "$schema": {
+      "type": "string"
+    },
+    "dxt_version": {
+      "type": "string",
+      "const": "0.4",
+      "description": "@deprecated Use manifest_version instead"
+    },
+    "manifest_version": {
+      "type": "string",
+      "const": "0.4"
+    },
+    "name": {
+      "type": "string"
+    },
+    "display_name": {
+      "type": "string"
+    },
+    "version": {
+      "type": "string"
+    },
+    "description": {
+      "type": "string"
+    },
+    "long_description": {
+      "type": "string"
+    },
+    "author": {
+      "type": "object",
+      "properties": {
+        "name": {
+          "type": "string"
+        },
+        "email": {
+          "type": "string",
+          "format": "email"
+        },
+        "url": {
+          "type": "string",
+          "format": "uri"
+        }
+      },
+      "required": [
+        "name"
+      ],
+      "additionalProperties": false
+    },
+    "repository": {
+      "type": "object",
+      "properties": {
+        "type": {
+          "type": "string"
+        },
+        "url": {
+          "type": "string",
+          "format": "uri"
+        }
+      },
+      "required": [
+        "type",
+        "url"
+      ],
+      "additionalProperties": false
+    },
+    "homepage": {
+      "type": "string",
+      "format": "uri"
+    },
+    "documentation": {
+      "type": "string",
+      "format": "uri"
+    },
+    "support": {
+      "type": "string",
+      "format": "uri"
+    },
+    "icon": {
+      "type": "string"
+    },
+    "icons": {
+      "type": "array",
+      "items": {
+        "type": "object",
+        "properties": {
+          "src": {
+            "type": "string"
+          },
+          "size": {
+            "type": "string",
+            "pattern": "^\\d+x\\d+$"
+          },
+          "theme": {
+            "type": "string",
+            "minLength": 1
+          }
+        },
+        "required": [
+          "src",
+          "size"
+        ],
+        "additionalProperties": false
+      }
+    },
+    "screenshots": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      }
+    },
+    "localization": {
+      "type": "object",
+      "properties": {
+        "resources": {
+          "type": "string",
+          "pattern": "\\$\\{locale\\}"
+        },
+        "default_locale": {
+          "type": "string",
+          "pattern": "^[A-Za-z0-9]{2,8}(?:-[A-Za-z0-9]{1,8})*$"
+        }
+      },
+      "required": [
+        "resources",
+        "default_locale"
+      ],
+      "additionalProperties": false
+    },
+    "server": {
+      "type": "object",
+      "properties": {
+        "type": {
+          "type": "string",
+          "enum": [
+            "python",
+            "node",
+            "binary",
+            "uv"
+          ]
+        },
+        "entry_point": {
+          "type": "string"
+        },
+        "mcp_config": {
+          "type": "object",
+          "properties": {
+            "command": {
+              "type": "string"
+            },
+            "args": {
+              "type": "array",
+              "items": {
+                "type": "string"
+              }
+            },
+            "env": {
+              "type": "object",
+              "additionalProperties": {
+                "type": "string"
+              }
+            },
+            "platform_overrides": {
+              "type": "object",
+              "additionalProperties": {
+                "type": "object",
+                "properties": {
+                  "command": {
+                    "$ref": "#/properties/server/properties/mcp_config/properties/command"
+                  },
+                  "args": {
+                    "$ref": "#/properties/server/properties/mcp_config/properties/args"
+                  },
+                  "env": {
+                    "$ref": "#/properties/server/properties/mcp_config/properties/env"
+                  }
+                },
+                "additionalProperties": false
+              }
+            }
+          },
+          "required": [
+            "command"
+          ],
+          "additionalProperties": false
+        }
+      },
+      "required": [
+        "type",
+        "entry_point"
+      ],
+      "additionalProperties": false
+    },
+    "tools": {
+      "type": "array",
+      "items": {
+        "type": "object",
+        "properties": {
+          "name": {
+            "type": "string"
+          },
+          "description": {
+            "type": "string"
+          }
+        },
+        "required": [
+          "name"
+        ],
+        "additionalProperties": false
+      }
+    },
+    "tools_generated": {
+      "type": "boolean"
+    },
+    "prompts": {
+      "type": "array",
+      "items": {
+        "type": "object",
+        "properties": {
+          "name": {
+            "type": "string"
+          },
+          "description": {
+            "type": "string"
+          },
+          "arguments": {
+            "type": "array",
+            "items": {
+              "type": "string"
+            }
+          },
+          "text": {
+            "type": "string"
+          }
+        },
+        "required": [
+          "name",
+          "text"
+        ],
+        "additionalProperties": false
+      }
+    },
+    "prompts_generated": {
+      "type": "boolean"
+    },
+    "keywords": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      }
+    },
+    "license": {
+      "type": "string"
+    },
+    "privacy_policies": {
+      "type": "array",
+      "items": {
+        "type": "string",
+        "format": "uri"
+      }
+    },
+    "compatibility": {
+      "type": "object",
+      "properties": {
+        "claude_desktop": {
+          "type": "string"
+        },
+        "platforms": {
+          "type": "array",
+          "items": {
+            "type": "string",
+            "enum": [
+              "darwin",
+              "win32",
+              "linux"
+            ]
+          }
+        },
+        "runtimes": {
+          "type": "object",
+          "properties": {
+            "python": {
+              "type": "string"
+            },
+            "node": {
+              "type": "string"
+            }
+          },
+          "additionalProperties": false
+        }
+      },
+      "additionalProperties": false
+    },
+    "user_config": {
+      "type": "object",
+      "additionalProperties": {
+        "type": "object",
+        "properties": {
+          "type": {
+            "type": "string",
+            "enum": [
+              "string",
+              "number",
+              "boolean",
+              "directory",
+              "file"
+            ]
+          },
+          "title": {
+            "type": "string"
+          },
+          "description": {
+            "type": "string"
+          },
+          "required": {
+            "type": "boolean"
+          },
+          "default": {
+            "anyOf": [
+              {
+                "type": "string"
+              },
+              {
+                "type": "number"
+              },
+              {
+                "type": "boolean"
+              },
+              {
+                "type": "array",
+                "items": {
+                  "type": "string"
+                }
+              }
+            ]
+          },
+          "multiple": {
+            "type": "boolean"
+          },
+          "sensitive": {
+            "type": "boolean"
+          },
+          "min": {
+            "type": "number"
+          },
+          "max": {
+            "type": "number"
+          }
+        },
+        "required": [
+          "type",
+          "title",
+          "description"
+        ],
+        "additionalProperties": false
+      }
+    },
+    "_meta": {
+      "type": "object",
+      "additionalProperties": {
+        "type": "object",
+        "additionalProperties": {}
+      }
+    }
+  },
+  "required": [
+    "name",
+    "version",
+    "description",
+    "author",
+    "server"
+  ],
+  "additionalProperties": false,
+  "$schema": "http://json-schema.org/draft-07/schema#"
+}

scripts/build-mcpb-schema.js

@@ -1,6 +1,7 @@
 import { McpbManifestSchema as McpbManifestSchema_v0_1 } from "../dist/schemas/0.1.js";
 import { McpbManifestSchema as McpbManifestSchema_v0_2 } from "../dist/schemas/0.2.js";
 import { McpbManifestSchema as McpbManifestSchema_v0_3 } from "../dist/schemas/0.3.js";
+import { McpbManifestSchema as McpbManifestSchema_v0_4 } from "../dist/schemas/0.4.js";
 import { McpbSignatureInfoSchema } from "../dist/shared/common.js";
 import { zodToJsonSchema } from "zod-to-json-schema";
 import fs from "node:fs/promises";
@@ -14,6 +15,7 @@ const versionedManifestSchemas = {
   "mcpb-manifest-v0.1": McpbManifestSchema_v0_1,
   "mcpb-manifest-v0.2": McpbManifestSchema_v0_2,
   "mcpb-manifest-v0.3": McpbManifestSchema_v0_3,
+  "mcpb-manifest-v0.4": McpbManifestSchema_v0_4,
 };
 
 // Other schemas

src/schemas/0.4.ts

@@ -0,0 +1,145 @@
+// v0.4: Adds UV runtime support for Python extensions
+import * as z from "zod";
+
+export const MANIFEST_VERSION = "0.4";
+
+const LOCALE_PLACEHOLDER_REGEX = /\$\{locale\}/i;
+const BCP47_REGEX = /^[A-Za-z0-9]{2,8}(?:-[A-Za-z0-9]{1,8})*$/;
+const ICON_SIZE_REGEX = /^\d+x\d+$/;
+
+export const McpServerConfigSchema = z.strictObject({
+  command: z.string(),
+  args: z.array(z.string()).optional(),
+  env: z.record(z.string(), z.string()).optional(),
+});
+
+export const McpbManifestAuthorSchema = z.strictObject({
+  name: z.string(),
+  email: z.string().email().optional(),
+  url: z.string().url().optional(),
+});
+
+export const McpbManifestRepositorySchema = z.strictObject({
+  type: z.string(),
+  url: z.string().url(),
+});
+
+export const McpbManifestPlatformOverrideSchema =
+  McpServerConfigSchema.partial();
+
+export const McpbManifestMcpConfigSchema = McpServerConfigSchema.extend({
+  platform_overrides: z
+    .record(z.string(), McpbManifestPlatformOverrideSchema)
+    .optional(),
+});
+
+export const McpbManifestServerSchema = z.strictObject({
+  type: z.enum(["python", "node", "binary", "uv"]),
+  entry_point: z.string(),
+  // mcp_config is optional for UV type (UV handles execution)
+  mcp_config: McpbManifestMcpConfigSchema.optional(),
+});
+
+export const McpbManifestCompatibilitySchema = z.strictObject({
+  claude_desktop: z.string().optional(),
+  platforms: z.array(z.enum(["darwin", "win32", "linux"])).optional(),
+  runtimes: z
+    .strictObject({
+      python: z.string().optional(),
+      node: z.string().optional(),
+    })
+    .optional(),
+});
+
+export const McpbManifestToolSchema = z.strictObject({
+  name: z.string(),
+  description: z.string().optional(),
+});
+
+export const McpbManifestPromptSchema = z.strictObject({
+  name: z.string(),
+  description: z.string().optional(),
+  arguments: z.array(z.string()).optional(),
+  text: z.string(),
+});
+
+export const McpbUserConfigurationOptionSchema = z.strictObject({
+  type: z.enum(["string", "number", "boolean", "directory", "file"]),
+  title: z.string(),
+  description: z.string(),
+  required: z.boolean().optional(),
+  default: z
+    .union([z.string(), z.number(), z.boolean(), z.array(z.string())])
+    .optional(),
+  multiple: z.boolean().optional(),
+  sensitive: z.boolean().optional(),
+  min: z.number().optional(),
+  max: z.number().optional(),
+});
+
+export const McpbManifestLocalizationSchema = z.strictObject({
+  resources: z
+    .string()
+    .regex(
+      LOCALE_PLACEHOLDER_REGEX,
+      'resources must include a "${locale}" placeholder',
+    ),
+  default_locale: z
+    .string()
+    .regex(
+      BCP47_REGEX,
+      "default_locale must be a valid BCP 47 locale identifier",
+    ),
+});
+
+export const McpbManifestIconSchema = z.strictObject({
+  src: z.string(),
+  size: z
+    .string()
+    .regex(
+      ICON_SIZE_REGEX,
+      'size must be in the format "WIDTHxHEIGHT" (e.g., "16x16")',
+    ),
+  theme: z.string().min(1, "theme cannot be empty when provided").optional(),
+});
+
+export const McpbManifestSchema = z
+  .strictObject({
+    $schema: z.string().optional(),
+    dxt_version: z
+      .literal(MANIFEST_VERSION)
+      .optional()
+      .describe("@deprecated Use manifest_version instead"),
+    manifest_version: z.literal(MANIFEST_VERSION).optional(),
+    name: z.string(),
+    display_name: z.string().optional(),
+    version: z.string(),
+    description: z.string(),
+    long_description: z.string().optional(),
+    author: McpbManifestAuthorSchema,
+    repository: McpbManifestRepositorySchema.optional(),
+    homepage: z.string().url().optional(),
+    documentation: z.string().url().optional(),
+    support: z.string().url().optional(),
+    icon: z.string().optional(),
+    icons: z.array(McpbManifestIconSchema).optional(),
+    screenshots: z.array(z.string()).optional(),
+    localization: McpbManifestLocalizationSchema.optional(),
+    server: McpbManifestServerSchema,
+    tools: z.array(McpbManifestToolSchema).optional(),
+    tools_generated: z.boolean().optional(),
+    prompts: z.array(McpbManifestPromptSchema).optional(),
+    prompts_generated: z.boolean().optional(),
+    keywords: z.array(z.string()).optional(),
+    license: z.string().optional(),
+    privacy_policies: z.array(z.string().url()).optional(),
+    compatibility: McpbManifestCompatibilitySchema.optional(),
+    user_config: z
+      .record(z.string(), McpbUserConfigurationOptionSchema)
+      .optional(),
+    _meta: z.record(z.string(), z.record(z.string(), z.any())).optional(),
+  })
+  .refine((data) => !!(data.dxt_version || data.manifest_version), {
+    message:
+      "Either 'dxt_version' (deprecated) or 'manifest_version' must be provided",
+  });

src/schemas/any.ts

@@ -3,13 +3,15 @@ import * as z from "zod";
 import * as v0_1 from "./0.1.js";
 import * as v0_2 from "./0.2.js";
 import * as v0_3 from "./0.3.js";
+import * as v0_4 from "./0.4.js";
 
 /**
- * Union schema that accepts any supported manifest version (0.1, 0.2, 0.3).
+ * Union schema that accepts any supported manifest version.
  * Use this when you need to validate manifests of any version.
  */
 export const McpbManifestSchema = z.union([
   v0_1.McpbManifestSchema,
   v0_2.McpbManifestSchema,
   v0_3.McpbManifestSchema,
+  v0_4.McpbManifestSchema,
 ]);

src/schemas/index.ts

@@ -1,10 +1,12 @@
 import { McpbManifestSchema as ManifestSchemaV0_1 } from "./0.1.js";
 import { McpbManifestSchema as ManifestSchemaV0_2 } from "./0.2.js";
 import { McpbManifestSchema as ManifestSchemaV0_3 } from "./0.3.js";
+import { McpbManifestSchema as ManifestSchemaV0_4 } from "./0.4.js";
 
 export * as v0_1 from "./0.1.js";
 export * as v0_2 from "./0.2.js";
 export * as v0_3 from "./0.3.js";
+export * as v0_4 from "./0.4.js";
 export * as vAny from "./any.js";
 
 /**
@@ -14,4 +16,5 @@ export const VERSIONED_MANIFEST_SCHEMAS = {
   "0.1": ManifestSchemaV0_1,
   "0.2": ManifestSchemaV0_2,
   "0.3": ManifestSchemaV0_3,
+  "0.4": ManifestSchemaV0_4,
 } as const;

src/schemas_loose/0.4.ts

@@ -0,0 +1,151 @@
+import * as z from "zod";
+
+export const MANIFEST_VERSION = "0.4";
+
+const LOCALE_PLACEHOLDER_REGEX = /\$\{locale\}/i;
+const BCP47_REGEX = /^[A-Za-z0-9]{2,8}(?:-[A-Za-z0-9]{1,8})*$/;
+const ICON_SIZE_REGEX = /^\d+x\d+$/;
+
+export const McpServerConfigSchema = z.object({
+  command: z.string(),
+  args: z.array(z.string()).optional(),
+  env: z.record(z.string(), z.string()).optional(),
+});
+
+export const McpbManifestAuthorSchema = z.object({
+  name: z.string(),
+  email: z.string().email().optional(),
+  url: z.string().url().optional(),
+});
+
+export const McpbManifestRepositorySchema = z.object({
+  type: z.string(),
+  url: z.string().url(),
+});
+
+export const McpbManifestPlatformOverrideSchema =
+  McpServerConfigSchema.partial();
+
+export const McpbManifestMcpConfigSchema = McpServerConfigSchema.extend({
+  platform_overrides: z
+    .record(z.string(), McpbManifestPlatformOverrideSchema)
+    .optional(),
+});
+
+export const McpbManifestServerSchema = z.object({
+  type: z.enum(["python", "node", "binary", "uv"]),
+  entry_point: z.string(),
+  // mcp_config is optional for UV type (UV handles execution)
+  mcp_config: McpbManifestMcpConfigSchema.optional(),
+});
+
+export const McpbManifestCompatibilitySchema = z
+  .object({
+    claude_desktop: z.string().optional(),
+    platforms: z.array(z.enum(["darwin", "win32", "linux"])).optional(),
+    runtimes: z
+      .object({
+        python: z.string().optional(),
+        node: z.string().optional(),
+      })
+      .optional(),
+  })
+  .passthrough();
+
+export const McpbManifestToolSchema = z.object({
+  name: z.string(),
+  description: z.string().optional(),
+});
+
+export const McpbManifestPromptSchema = z.object({
+  name: z.string(),
+  description: z.string().optional(),
+  arguments: z.array(z.string()).optional(),
+  text: z.string(),
+});
+
+export const McpbUserConfigurationOptionSchema = z.object({
+  type: z.enum(["string", "number", "boolean", "directory", "file"]),
+  title: z.string(),
+  description: z.string(),
+  required: z.boolean().optional(),
+  default: z
+    .union([z.string(), z.number(), z.boolean(), z.array(z.string())])
+    .optional(),
+  multiple: z.boolean().optional(),
+  sensitive: z.boolean().optional(),
+  min: z.number().optional(),
+  max: z.number().optional(),
+});
+
+export const McpbManifestLocalizationSchema = z
+  .object({
+    resources: z
+      .string()
+      .regex(
+        LOCALE_PLACEHOLDER_REGEX,
+        'resources must include a "${locale}" placeholder',
+      ),
+    default_locale: z
+      .string()
+      .regex(
+        BCP47_REGEX,
+        "default_locale must be a valid BCP 47 locale identifier",
+      ),
+  })
+  .passthrough();
+
+export const McpbManifestIconSchema = z
+  .object({
+    src: z.string(),
+    size: z
+      .string()
+      .regex(
+        ICON_SIZE_REGEX,
+        'size must be in the format "WIDTHxHEIGHT" (e.g., "16x16")',
+      ),
+    theme: z.string().min(1).optional(),
+  })
+  .passthrough();
+
+export const McpbManifestSchema = z
+  .object({
+    $schema: z.string().optional(),
+    dxt_version: z
+      .literal(MANIFEST_VERSION)
+      .optional()
+      .describe("@deprecated Use manifest_version instead"),
+    manifest_version: z.literal(MANIFEST_VERSION).optional(),
+    name: z.string(),
+    display_name: z.string().optional(),
+    version: z.string(),
+    description: z.string(),
+    long_description: z.string().optional(),
+    author: McpbManifestAuthorSchema,
+    repository: McpbManifestRepositorySchema.optional(),
+    homepage: z.string().url().optional(),
+    documentation: z.string().url().optional(),
+    support: z.string().url().optional(),
+    icon: z.string().optional(),
+    icons: z.array(McpbManifestIconSchema).optional(),
+    screenshots: z.array(z.string()).optional(),
+    localization: McpbManifestLocalizationSchema.optional(),
+    server: McpbManifestServerSchema,
+    tools: z.array(McpbManifestToolSchema).optional(),
+    tools_generated: z.boolean().optional(),
+    prompts: z.array(McpbManifestPromptSchema).optional(),
+    prompts_generated: z.boolean().optional(),
+    keywords: z.array(z.string()).optional(),
+    license: z.string().optional(),
+    privacy_policies: z.array(z.string().url()).optional(),
+    compatibility: McpbManifestCompatibilitySchema.optional(),
+    user_config: z
+      .record(z.string(), McpbUserConfigurationOptionSchema)
+      .optional(),
+    _meta: z.record(z.string(), z.record(z.string(), z.any())).optional(),
+  })
+  .passthrough()
+  .refine((data) => !!(data.dxt_version || data.manifest_version), {
+    message:
+      "Either 'dxt_version' (deprecated) or 'manifest_version' must be provided",
+  });

src/schemas_loose/index.ts

@@ -1,3 +1,4 @@
 export * as v0_1 from "./0.1.js";
 export * as v0_2 from "./0.2.js";
 export * as v0_3 from "./0.3.js";
+export * as v0_4 from "./0.4.js";

src/shared/constants.ts

@@ -1,14 +1,16 @@
 import { McpbManifestSchema as ManifestSchemaV0_1 } from "../schemas/0.1.js";
 import { McpbManifestSchema as ManifestSchemaV0_2 } from "../schemas/0.2.js";
 import { McpbManifestSchema as ManifestSchemaV0_3 } from "../schemas/0.3.js";
+import { McpbManifestSchema as ManifestSchemaV0_4 } from "../schemas/0.4.js";
 import { McpbManifestSchema as LooseManifestSchemaV0_1 } from "../schemas_loose/0.1.js";
 import { McpbManifestSchema as LooseManifestSchemaV0_2 } from "../schemas_loose/0.2.js";
 import { McpbManifestSchema as LooseManifestSchemaV0_3 } from "../schemas_loose/0.3.js";
+import { McpbManifestSchema as LooseManifestSchemaV0_4 } from "../schemas_loose/0.4.js";
 
 /**
  * Latest manifest version - indicates the maximum supported version by vAny schema
  */
-export const LATEST_MANIFEST_VERSION = "0.3" as const;
+export const LATEST_MANIFEST_VERSION = "0.4" as const;
 
 /**
  * Default manifest version for new packages
@@ -22,6 +24,7 @@ export const MANIFEST_SCHEMAS = {
   "0.1": ManifestSchemaV0_1,
   "0.2": ManifestSchemaV0_2,
   "0.3": ManifestSchemaV0_3,
+  "0.4": ManifestSchemaV0_4,
 } as const;
 
 /**
@@ -31,4 +34,5 @@ export const MANIFEST_SCHEMAS_LOOSE = {
   "0.1": LooseManifestSchemaV0_1,
   "0.2": LooseManifestSchemaV0_2,
   "0.3": LooseManifestSchemaV0_3,
+  "0.4": LooseManifestSchemaV0_4,
 } as const;