/**
* Inspection tools - stack_trace, scopes, variables, evaluate, threads
*/
import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { z } from "zod";
import { Variable } from "../dap-client.js";
import { sessionManager } from "../session-manager.js";
import { sessionIdParam, textResponse } from "./types.js";
import { sessionPrefix, formatStackFrame, formatVariable } from "../utils.js";
export function registerInspectionTools(server: McpServer): void {
// Tool: stack_trace
server.tool(
"stack_trace",
"Get the current call stack",
{
threadId: z.number().optional().describe("Thread ID"),
depth: z
.number()
.optional()
.default(20)
.describe("Maximum number of frames to return"),
sessionId: sessionIdParam,
},
async ({ threadId, depth, sessionId }) => {
const session = sessionManager.getSession(sessionId);
const frames = await session.getStackTrace(threadId, depth);
if (frames.length === 0) {
return textResponse(
`${sessionPrefix(session.id)}No stack frames available. Is the program stopped?`
);
}
const formatted = frames.map(formatStackFrame).join("\n");
return textResponse(`${sessionPrefix(session.id)}Call Stack:\n${formatted}`);
}
);
// Tool: scopes
server.tool(
"scopes",
"Get variable scopes for a stack frame",
{
frameId: z.number().describe("Stack frame ID (from stack_trace)"),
sessionId: sessionIdParam,
},
async ({ frameId, sessionId }) => {
const session = sessionManager.getSession(sessionId);
const scopes = await session.getScopes(frameId);
const lines = scopes.map(
(s) => `${s.name} (ref: ${s.variablesReference}, expensive: ${s.expensive})`
);
return textResponse(`${sessionPrefix(session.id)}Scopes:\n${lines.join("\n")}`);
}
);
// Tool: variables
server.tool(
"variables",
"Get variables from a scope or variable container",
{
variablesReference: z
.number()
.describe("Variables reference (from scopes or parent variable)"),
sessionId: sessionIdParam,
},
async ({ variablesReference, sessionId }) => {
const session = sessionManager.getSession(sessionId);
const vars = await session.getVariables(variablesReference);
if (vars.length === 0) {
return textResponse(`${sessionPrefix(session.id)}No variables in this scope`);
}
const lines = vars.map((v) => formatVariable(v, 0));
return textResponse(`${sessionPrefix(session.id)}Variables:\n${lines.join("\n")}`);
}
);
// Tool: evaluate
server.tool(
"evaluate",
"Evaluate an expression in the current debug context",
{
expression: z.string().describe("Expression to evaluate"),
frameId: z
.number()
.optional()
.describe("Stack frame ID for context (from stack_trace)"),
sessionId: sessionIdParam,
},
async ({ expression, frameId, sessionId }) => {
const session = sessionManager.getSession(sessionId);
const result = await session.evaluate(expression, frameId);
const type = result.type ? ` (${result.type})` : "";
return textResponse(`${sessionPrefix(session.id)}${expression}${type} = ${result.result}`);
}
);
// Tool: threads
server.tool(
"threads",
"List all threads in the debugged process",
{
sessionId: sessionIdParam,
},
async ({ sessionId }) => {
const session = sessionManager.getSession(sessionId);
const threads = await session.getThreads();
const lines = threads.map((t) => ` Thread ${t.id}: ${t.name}`);
return textResponse(`${sessionPrefix(session.id)}Threads:\n${lines.join("\n")}`);
}
);
}
