Choose Your Runtime
Compare the available agent runtimes and pick the right one for your use case.
x3s.host supports five agent runtimes. Each one is a different piece of open-source agent software, packaged and managed for you.
Runtimes at a glance
| Runtime | Best for | Browser included | Auth method |
|---|---|---|---|
| OpenClaw | Most use cases — interactive agent with full tool library | ✓ | Username + password |
| Moltis | Multi-model workloads and API-first integrations | ✓ | Runtime token |
| OpenFang | Lightweight Rust-based agent, no API key required at deploy | ✓ | API key |
| ZeroClaw | High-performance Rust runtime | ✓ | Pairing code |
| NullClaw | Minimal footprint, zero-overhead Zig binary | ✓ | Pairing code |
Which should I choose?
Start with OpenClaw if you're unsure. It has the most complete feature set, supports browser automation, and works well for the widest range of tasks.
Choose Moltis if you're routing across multiple AI models or building API-driven integrations that need a lightweight orchestration layer.
Choose OpenFang if you want a Rust-native runtime and prefer not to configure an API key at deploy time.
Choose ZeroClaw or NullClaw if you have specific performance requirements or are already familiar with these runtimes and their pairing-code auth flow.
What every runtime includes
All runtimes on x3s.host come with:
- A dedicated Public URL (
https://your-agent.x3s.host) with automatic TLS - A built-in browser sidecar for web automation tasks
- An in-dashboard Terminal for direct shell access
- Optional Tailscale integration for private SSH access
- Secrets management — inject API keys and tokens without editing config files
Switching runtimes
You can deploy additional agents with different runtimes at any time — each uses one subscription slot. There is no migration path between runtime types; if you want to switch, deploy a new agent and decommission the old one.