feat: add dynamic tool registration for plugins and external services (#2420)

packages/plugin/src/index.ts

@@ -18,9 +18,34 @@ export type PluginInput = {
   directory: string
   worktree: string
   $: BunShell
+  Tool: {
+    define(
+      id: string,
+      init: any | (() => Promise<any>)
+    ): any
+  }
+  z: any // Zod instance for creating schemas
 }
 export type Plugin = (input: PluginInput) => Promise<Hooks>
 
+// Lightweight schema spec for HTTP-registered tools
+export type HttpParamSpec = {
+  type: "string" | "number" | "boolean" | "array"
+  description?: string
+  optional?: boolean
+  items?: "string" | "number" | "boolean"
+}
+export type HttpToolRegistration = {
+  id: string
+  description: string
+  parameters: {
+    type: "object"
+    properties: Record<string, HttpParamSpec>
+  }
+  callbackUrl: string
+  headers?: Record<string, string>
+}
+
 export interface Hooks {
   event?: (input: { event: Event }) => Promise<void>
   config?: (input: Config) => Promise<void>
@@ -99,4 +124,16 @@ export interface Hooks {
       metadata: any
     },
   ) => Promise<void>
+  /**
+   * Allow plugins to register additional tools with the server.
+   * Use registerHTTP to add a tool that calls back to your plugin/service.
+   * Use register to add a native/local tool with direct function execution.
+   */
+  "tool.register"?: (
+    input: {},
+    output: {
+      registerHTTP: (tool: HttpToolRegistration) => void | Promise<void>
+      register: (tool: any) => void | Promise<void>  // Tool.Info type from opencode
+    },
+  ) => Promise<void>
 }