You shouldn't have to choose between simple and powerful. Or between the cloud and control.
So we stopped choosing. Sandcastle is an open-source orchestrator for AI agents — define a workflow in one file, run it on any model, ship it anywhere on your own rules, and let it get sharper every run.
$pip install sandcastle-aiBuild
anything.
Complex agents from one simple file. 22 step types — parallel fan-out, conditions, loops, gates, deterministic $0 steps. Or skip the YAML entirely and describe what you want in a sentence; Sandcastle designs the workflow.
Any
model.
Model-independent by design. Claude, GPT, Mistral, Gemini, Llama — or fully local. Swap providers in one line. And when one goes down, auto-failover moves to the next while you sleep.
Anywhere,
your rules.
Cloud, your own server, fully isolated or air-gapped, or EU-only. The same workflow, your gate. EU data residency is built in — when you enable it, every model call stays in region.
- Cloudready
- Your server (self-host)ready
- Isolated / air-gappedready
- EU-only residencyenabled
It
learns.
It self-tunes on what succeeds and heals what fails. Every run is recorded — so you can replay your past workflows against new models and keep the winner. Smarter over time, on autopilot.
No feature gates. One version. Every line above ships free.
The declaration ends. The build begins.