A language for verified AI agent protocols.
Lingua Universale
A language for verified AI agent protocols.
**Try it in your browser** -- no install needed. **Watch AI agents live** -- 3 agents on a verified protocol.
The Problem
Your AI agents talk to each other, but nothing guarantees they follow the rules. Wrong sender, wrong message order, missing steps -- and you only find out in production.
Lingua Universale (LU) is a type checker for AI agent conversations. You define the protocol, LU proves it's correct, and the runtime enforces it.
from cervellaswarm_lingua_universale import Protocol, ProtocolStep, MessageKind, SessionChecker, TaskRequest
# Define: who sends what, to whom, in what order
review = Protocol(name="Review", roles=("dev", "reviewer"), elements=(
ProtocolStep(sender="dev", receiver="reviewer", message_kind=MessageKind.TASK_REQUEST),
ProtocolStep(sender="reviewer", receiver="dev", message_kind=MessageKind.TASK_RESULT),
))
checker = SessionChecker(review)
checker.send("dev", "reviewer", TaskRequest(task_id="1", description="Review auth")) # OK
checker.send("dev", "reviewer", TaskRequest(task_id="2", description="Oops")) # ProtocolViolation!
# ^^^ wrong turn: reviewer must send next
The protocol says reviewer goes next. The runtime blocks it. Not because you trust the code -- because the session type makes it impossible.
Install
pip install cervellaswarm-lingua-universale
Or try it first: **Playground** (runs in your browser via Pyodide).
Write a Protocol
protocol DelegateTask:
roles: supervisor, worker, validator
supervisor asks worker to execute analysis
worker returns result to supervisor
supervisor asks validator to verify result
when validator decides:
pass:
validator returns approval to supervisor
fail:
validator sends feedback to supervisor
properties:
always terminates
no deadlock
no deletion
all roles participate
Then verify it:
lu verify delegate_task.lu
[1/4] always_terminates ... PROVED
[2/4] no_deadlock ... PROVED
[3/4] no_deletion ... PROVED
[4/4] all_roles_participate ... PROVED
All 4 properties PASSED.
Mathematical proof. Not a test that passes today and fails tomorrow.
What You Get
| Feature | Description |
|---|---|
| Full compiler | Tokenizer, parser (64 rules), AST, contract checker, Python codegen |
| 9 verified properties | always_terminates, no_deadlock, no_deletion, role_exclusive, and more |
| 20 stdlib protocols | AI/ML, Business, Communication, Data, Security -- ready to use |
| Linter + Formatter | lu lint (10 rules) + lu fmt (zero-config, like gofmt) |
| LSP server | Diagnostics, hover, completion, go-to-definition, formatting |
| VS Code extension | Install from Marketplace |
| Interactive chat | lu chat -- build protocols conversationally (English, Italian, Portuguese) |
| Browser playground | Try it now -- Check, Lint, Run, Chat |
| Lean 4 bridge | Generate and verify mathematical proofs |
| REPL | lu repl for interactive exploration |
| Project scaffolding | lu init --template rag_pipeline from 20 verified templates |
36 modules. 3920 tests. Zero external dependencies. Pure Python stdlib.
CLI
lu check file.lu # Parse and compile
lu verify file.lu # Formal property verification
lu run file.lu # Execute
lu lint file.lu # 10 style and correctness rules
lu fmt file.lu # Zero-config auto-formatter
lu chat --lang en # Build a protocol conversationally
lu demo --lang it # See the La Nonna demo
lu init --template NAME # Scaffold from stdlib templates
lu mcp-audit --manifest t.json # Audit MCP server protocols
lu repl # Inte
Tools (4)
parse_protocolsParses and compiles protocol definitions into an AST.verify_messagesValidates message sequences against defined session types.check_safety_propertiesPerforms formal verification of safety properties like deadlock freedom.browse_stdlib_templatesLists and retrieves available standard library protocol templates.Configuration
{"mcpServers": {"cervellaswarm": {"command": "lu", "args": ["mcp-server"]}}}