Ollama: connection refused on localhost:11434

Your client (curl, an SDK, or another tool) is trying to reach the Ollama HTTP server at port 11434 but Ollama isn't running there. Common causes:

• ollama serve was never started (most common on Linux without the systemd service)
• Ollama is running but bound to a different host/port (e.g., OLLAMA_HOST=0.0.0.0 for remote access)
• Firewall blocking localhost (rare but happens with overzealous corp security)

Start Ollama:

# macOS / Linux foreground
ollama serve
# In another terminal, verify:
curl http://localhost:11434/api/tags

Linux (run as a service):

sudo systemctl start ollama
sudo systemctl enable ollama  # auto-start on boot

Windows: The Ollama installer registers a Windows service that should auto-start. Check Services (services.msc) for "Ollama" — set it to Automatic.

If running on a non-default port, point your client there:

export OLLAMA_HOST=http://localhost:11500
# Or in your code, set the base URL explicitly

If running in Docker, make sure the port is published:

docker run -d -p 11434:11434 --name ollama ollama/ollama