add_watch
Monitor PHP variable values during debugging by adding watch expressions that evaluate on each breakpoint.
Instructions
Add a watch expression that will be evaluated on each break. Watch expressions persist across steps.
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| expression | Yes | PHP expression to watch (e.g., '$user->id', 'count($items)') |
Implementation Reference
- src/tools/advanced.ts:42-58 (handler)Handler function for the 'add_watch' tool. It calls ctx.watchManager.addWatch(expression) to add the watch and returns a success response with the watch ID and expression.async ({ expression }) => { const watch = ctx.watchManager.addWatch(expression); return { content: [ { type: 'text', text: JSON.stringify({ success: true, watch: { id: watch.id, expression: watch.expression, }, }), }, ], }; }
- src/tools/advanced.ts:37-59 (registration)Registration of the 'add_watch' MCP tool on the server, including name, description, input schema, and handler.'add_watch', 'Add a watch expression that will be evaluated on each break. Watch expressions persist across steps.', { expression: z.string().describe("PHP expression to watch (e.g., '$user->id', 'count($items)')"), }, async ({ expression }) => { const watch = ctx.watchManager.addWatch(expression); return { content: [ { type: 'text', text: JSON.stringify({ success: true, watch: { id: watch.id, expression: watch.expression, }, }), }, ], }; } );
- src/tools/advanced.ts:40-40 (schema)Input schema for the 'add_watch' tool, defining the 'expression' parameter as a string.expression: z.string().describe("PHP expression to watch (e.g., '$user->id', 'count($items)')"),
- src/session/watch-manager.ts:40-52 (helper)Core implementation of adding a watch expression in WatchManager class. Creates a unique ID, initializes WatchExpression object, stores it in a Map, and logs the addition.addWatch(expression: string): WatchExpression { const id = `watch_${++this.watchIdCounter}`; const watch: WatchExpression = { id, expression, hasChanged: false, evaluationCount: 0, createdAt: new Date(), }; this.watches.set(id, watch); logger.debug(`Watch added: ${id} = ${expression}`); return watch; }
- src/session/watch-manager.ts:12-21 (schema)TypeScript interface defining the structure of a WatchExpression used by the add_watch tool.id: string; expression: string; lastValue?: Property | null; previousValue?: Property | null; hasChanged: boolean; errorMessage?: string; evaluationCount: number; createdAt: Date; lastEvaluatedAt?: Date; }