A formal, deterministic, language-agnostic specification language for intent contracts.

ICL defines a standard way to express intent contracts — machine-verifiable declarations of what a system intends to do. Every contract is deterministic (same input → identical output), verifiable (all properties machine-checkable), and bounded (execution bounded in memory and time).

contract HelloWorld {
  version: "1.0"
  identity {
    name: "hello-world"
  }
  intent {
    action: "greet"
    description: "A simple greeting contract"
  }
}

Guardrails and system prompts are suggestions an LLM can ignore or misinterpret. ICL contracts are mathematically enforced walls — verified before execution, impossible to bypass.

Where ICL is used: Trading agents that CANNOT exceed limits · Surgical robots that MUST stop if sensors fail · Drones that CANNOT enter restricted airspace · Code deploy agents that CANNOT ship without passing tests

See the full ICL vs Guardrails — 50+ real-world examples for when (and when not) to use ICL.

# Rust
cargo install icl-cli

# Python
pip install icl-runtime

# JavaScript
npm install icl-runtime

One Rust codebase, compiled to every target:

ICL Text → Parser → AST → Normalizer → Canonical Form
                           ↓
                        Verifier → Type Check + Invariants + Determinism
                           ↓
                        Executor → Sandboxed Execution

• Determinism is non-negotiable — same input → identical output, always
• Spec is authoritative — the specification defines truth, code must match
• Single codebase — all logic in Rust, compiled to every platform
• Verifiable — all contract properties are machine-checkable
• Bounded — all execution bounded in memory and time

MIT