---
title: CallFrame
description: CallFrame represents a single shadow stack frame from the VM.
source_url:
  html: https://thru.org/docs/api-ref/grpc/messages/thru/services/v1/call-frame/
  md: https://thru.org/docs/api-ref/grpc/messages/thru/services/v1/call-frame.md
---

# CallFrame

CallFrame represents a single shadow stack frame from the VM.

**Package:** `thru.services.v1`

## Fields

| Field | Type | # | Description |
| - | - | - | - |
| `program_acc_idx` | `uint32` | 1 · optional | |
| `program_counter` | `uint64` | 2 · optional | |
| `stack_pointer` | `uint64` | 3 · optional | |
| `saved_registers` | repeated `uint64` | 4 · optional | |
| `stack_window` | `bytes` | 5 · optional | Up to 1024 bytes above sp |
| `stack_window_base` | `uint64` | 6 · optional | Virtual address of first byte (== stack\_pointer) |