Purpose-built runtime for
AI agent execution
Run agent code and tools inside an isolated environment with deterministic replay. Move from “it worked on my machine” to “we can prove what happened.”
Spin up isolated environments in microseconds for every agent run.
Every execution is reproducible. Same inputs, same outputs, always.
Run thousands of workflow variations cheaply for evals and search.
Three parts, one contract
Isolated execution
environment
Agent code runs in a minimal, isolated environment with a virtual filesystem and controlled time.
Sandbox requests,
host decides
Side effects happen through host operations you define. Credentials and policy stay outside.
Deterministic replay
for every run
Every run produces a compact record. Reproduce what happened exactly.
Nothing is allowed
unless you grant it
Tool access is explicit and validated at runtime. Define what your agent can touch, scope parameters, and block everything else by default.
Every run produces
an audit artifact
Structured records of inputs, tool calls, outputs, and replay bundles. Export incident reports for audits or customers.
What you can do with it
Agent Debugging
Reproduce failures exactly. Diff runs. Debug without guesswork.
Safe Tool Use
Let agents use shell utilities and file workflows without ambient access.
Parallel Evals
Run many variations of a workflow cheaply for evals, search, or testing.
Enterprise Isolation
A safer way to run agent workloads without heavy per-run infrastructure.
Security that doesn't rely on “please behave”
Most agent security today is prompts and policies. Saph assumes the agent will eventually do something weird and designs around that.
Isolation
Limits blast radius. Every agent runs in its own sandbox.
Capabilities
Prevents ambient authority. Nothing runs unless explicitly granted.
Replay
Makes incidents understandable. Replay any execution exactly.
Runtime now, control later
Start with the runtime. Add enforcement when your automation gets serious.
Ship agents that can
execute safely
Try the sandbox or talk to us about your use case.