---
title: "Fix JSON-RPC error -32700: Parse error / Invalid Windows backslashes (-32700)"
slug: "windows-backslash-json-parse-error"
code: "-32700"
category: "Configuration Syntax"
severity: "High"
canonical: "https://mcp-codex.com/errors/windows-backslash-json-parse-error"
source: "MCP Codex (https://mcp-codex.com)"
dateModified: "2026-09-28"
---

# Fix JSON-RPC error -32700: Parse error / Invalid Windows backslashes (-32700)

**Category**: Configuration Syntax | **Severity**: High

## Symptom
Config file fails to load or server crashes on startup with 'SyntaxError: Bad escaped character in JSON'.

## Root Cause
Single backslashes used in Windows file paths (e.g. 'C:\Projects') violate JSON string escape rules.

## Remediation & Quick Fix
Replace single backslashes with forward slashes (e.g. 'C:/Projects') or double-escaped backslashes ('C:\\Projects').

## OS Remediation Commands

### MAC
```bash
# Not applicable to macOS
```

### WINDOWS
```bash
# Format Windows paths with forward slashes in JSON:
"args": ["C:/Projects/my-app"]
```

### LINUX
```bash
# Not applicable to Linux
```

## Correct Configuration Example
```json
{
  "mcpServers": {
    "filesystem": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-filesystem", "C:/Projects/workspace"]
    }
  }
}
```

## Canonical Diagnostic Link
https://mcp-codex.com/errors/windows-backslash-json-parse-error

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