lu_verify_message
Replays message history against a protocol definition to validate whether the next message is allowed, returning validity, violation details, or expected step.
Instructions
Verify whether a message is valid in the context of an ongoing session.
Replays the existing message history against the protocol, then checks
whether next_message is the expected next step.
Args:
protocol_text: Full .lu protocol definition text.
messages: List of already-sent messages, each a dict with keys:
sender (str), receiver (str), action (str).
Actions are LU action names: "asks", "returns", "sends",
"proposes", "tells". These match the verbs in .lu source files.
next_message: The message to validate, same format as above.
Returns:
JSON string:
On success: {"valid": true, "step": N, "next_expected": "..."}
On violation: {"valid": false, "violation": "...", "expected": "...", "got": "..."}
On error: {"valid": false, "error": "..."}
Example:
protocol_text = "protocol Ping:\n roles: a, b\n a asks b to ping\n b returns pong to a\n properties:\n always terminates\n"
messages = [{"sender": "a", "receiver": "b", "action": "asks"}]
next_message = {"sender": "b", "receiver": "a", "action": "returns"}
# Returns: {"valid": true, ...}Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| protocol_text | Yes | ||
| messages | Yes | ||
| next_message | Yes |
Output Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |