macOS: SQLite "disk I/O error"

Troubleshooting

This guide covers common issues and their solutions when running ContextForge.

macOS: SQLite "disk I/O error"

If the gateway fails on macOS with sqlite3.OperationalError: disk I/O error (works on Linux/Docker), it's usually a filesystem/locking quirk rather than a schema bug.

Quick Fixes

Avoid iCloud-synced directories:

• Don't clone/run the repo under ~/Documents or ~/Desktop if iCloud "Desktop & Documents" sync is enabled
• Use a project folder directly under your home directory:

mkdir -p "$HOME/mcp-context-forge" && cd "$HOME/mcp-context-forge"

Use a safe, local APFS path for SQLite:

Avoid iCloud/Dropbox/OneDrive/Google Drive, network shares, or external exFAT/NAS.

=== "Application Support" bash mkdir -p "$HOME/Library/Application Support/mcpgateway" export DATABASE_URL="sqlite:////Users/$USER/Library/Application Support/mcpgateway/mcp.db"

=== "Project Local" bash mkdir -p "$HOME/mcp-context-forge/data" export DATABASE_URL="sqlite:////Users/$USER/mcp-context-forge/data/mcp.db"

Additional Steps

Clean stale SQLite artifacts after any crash:

pkill -f mcpgateway || true && rm -f mcp.db-wal mcp.db-shm mcp.db-journal

Reduce startup concurrency:

GUNICORN_WORKERS=1 make serve  # or use `make dev` which runs single-process

Run the diagnostic helper:

python3 scripts/test_sqlite.py --verbose

Lower pool pressure while debugging:

DB_POOL_SIZE=10 DB_MAX_OVERFLOW=0 DB_POOL_TIMEOUT=60 DB_MAX_RETRIES=10 DB_RETRY_INTERVAL_MS=5000

Disable file-lock leader path (temporary):

export CACHE_TYPE=none

Update SQLite and ensure Python links against it:

brew install sqlite3 && brew link --force sqlite3
brew install python3 && /opt/homebrew/bin/python3 -c 'import sqlite3; print(sqlite3.sqlite_version)'

!!! tip "Full SQLite Guide" See the Migration Guide for deeper steps including WAL cleanup, integrity check, and recovery.

WSL2: Port Publishing Issues

When using rootless Podman or Docker Desktop on WSL2, you may encounter port publishing issues.

Diagnose the Listener

# Inside your WSL distro
ss -tlnp | grep 4444        # Use ss
netstat -anp | grep 4444    # or netstat

!!! info "IPv6 Wildcard" Seeing :::4444 LISTEN rootlessport is normal - the IPv6 wildcard socket (::) also accepts IPv4 traffic when net.ipv6.bindv6only = 0 (default on Linux).

Why localhost Fails on Windows

WSL 2's NAT layer rewrites only the IPv6 side of the dual-stack listener. From Windows, http://127.0.0.1:4444 (or Docker Desktop's "localhost") therefore times out.

Fix for Podman Rootless

# Inside the WSL distro
echo "wsl" | sudo tee /etc/containers/podman-machine
systemctl --user restart podman.socket

ss should now show 0.0.0.0:4444 instead of :::4444, and the service becomes reachable from Windows and the LAN.

Fix for Docker Desktop (> 4.19)

Docker Desktop adds a "WSL integration" switch per-distro. Turn it on for your distro, restart Docker Desktop, then restart the container:

docker restart mcpgateway

Gateway Exits Immediately

Error: "Failed to read DATABASE_URL" or similar startup failures.

Solution: Copy .env.example to .env and configure required variables:

cp .env.example .env

Then edit DATABASE_URL, JWT_SECRET_KEY, BASIC_AUTH_PASSWORD, etc. Missing or empty required vars cause a fast-fail at startup.

See the Configuration Reference for all available options.

Common Issues

Getting Help

• GitHub Issues — Report bugs or request features
• Discussions — Ask questions and share ideas
• API Usage Guide — Comprehensive API examples