can1357/oh-my-pi · error · ToolError

count is required for read_memory

Error message

count is required for read_memory

What it means

For action="read_memory", the tool requires an explicit count of bytes to read; the DAP readMemory request needs it to bound the transfer. The tool rejects the call with a ToolError before any adapter round-trip when params.count is undefined. This prevents unbounded memory reads and matches the DAP request contract.

Source

Thrown at packages/coding-agent/src/tools/debug.ts:1022

					resolveDisassemblyReference(params.memory_reference),
					params.instruction_count,
					params.offset,
					params.instruction_offset,
					params.resolve_symbols,
					combinedSignal,
					timeoutSec * 1000,
				);
				details.snapshot = response.snapshot;
				details.disassembly = response.instructions;
				return result.text(formatDisassembly(response.instructions)).done();
			}
			case "read_memory": {
				requireCapability("supportsReadMemoryRequest", "memory reads");
				if (!params.memory_reference) {
					throw new ToolError("memory_reference is required for read_memory");
				}
				if (params.count === undefined) {
					throw new ToolError("count is required for read_memory");
				}
				const response = await dapSessionManager.readMemory(
					params.memory_reference,
					params.count,
					params.offset,
					combinedSignal,
					timeoutSec * 1000,
				);
				details.snapshot = response.snapshot;
				details.memoryAddress = response.address;
				details.memoryData = response.data;
				details.unreadableBytes = response.unreadableBytes;
				return result.text(formatMemoryRead(response.address, response.data, response.unreadableBytes)).done();
			}
			case "write_memory": {
				requireCapability("supportsWriteMemoryRequest", "memory writes");
				if (!params.memory_reference) {
					throw new ToolError("memory_reference is required for write_memory");

View on GitHub (pinned to 9690622007)

Solutions

1. Add an explicit byte count to the call, e.g. count: 256, keeping it reasonable (reads are formatted as hex dumps).
2. Confirm the parameter name is count, not size/length/bytes.
3. If you want progressive reading, keep count fixed and vary params.offset instead of omitting count.
4. Pair with a valid memory_reference — the memory_reference check runs first, so this error means that check already passed.

Example fix

// before
await debugTool.run({ action: "read_memory", memory_reference: ref });
// after
await debugTool.run({ action: "read_memory", memory_reference: ref, count: 256 });

if (typeof count !== "number" || !Number.isInteger(count) || count <= 0) throw new Error("read_memory requires a positive integer count");

function hasCount(p: { count?: number }): p is { count: number } {
  return typeof p.count === "number" && p.count > 0;
}

try {
  await debugTool.run({ action: "read_memory", memory_reference: ref, count: 256 });
} catch (err) {
  if (err instanceof ToolError && err.message.includes("count is required")) {
    // supply a sensible default byte count and retry once
  } else throw err;
}

When it happens

Trigger: Calling the debug tool with action="read_memory" and a valid memory_reference but omitting params.count (or passing undefined). Also occurs when count is accidentally placed under a different key (bytes, size, length).

Common situations: LLM-generated tool calls that include the memory reference but forget the byte count; scripts ported from DAP clients where count was optional at a higher abstraction layer; callers expecting a default read size that this tool does not provide.

Understand the failure class

Background: Missing required parameter errors: what 'X is required' and 'the required X param is missing' mean, and how to fix them — this error's family across 27 libraries.

Related errors

• memory_reference is required for read_memory
• memory_reference is required for write_memory
• data is required for write_memory
• command is required for custom_request
• Debugger reported no threads.

AI-assisted analysis of can1357/oh-my-pi@9690622007 (2026-08-31). Data as JSON: /api/errors/7801e5ec95476077. Report an issue: GitHub.