moss-langgraph

MOSS signing integration for LangGraph. Unsigned output is broken output.

Installation

pip install moss-langgraph

Quick Start: Explicit Signing (Recommended)

Sign node outputs, checkpoints, and state transitions:

from moss_langgraph import sign_node_output, sign_checkpoint, sign_state_transition

# Sign a node output
state = {"messages": ["Hello"], "step": 1}
result = sign_node_output(state, agent_id="my-graph", node="processor")
print(f"Signed: {result.signature[:20]}...")

# Sign a checkpoint
checkpoint = {"thread_id": "t1", "values": state}
result = sign_checkpoint(checkpoint, agent_id="my-graph", checkpoint_id="cp_1")

# Sign a state transition
result = sign_state_transition(
    from_state={"step": 1},
    to_state={"step": 2},
    agent_id="my-graph",
    from_node="step1",
    to_node="step2"
)

Enterprise Mode

Set MOSS_API_KEY for automatic policy evaluation:

import os
os.environ["MOSS_API_KEY"] = "your-api-key"

from moss_langgraph import sign_node_output, enterprise_enabled

print(f"Enterprise: {enterprise_enabled()}")  # True

result = sign_node_output(
    {"action": "high_value_trade"},
    agent_id="trading-graph",
    node="executor",
    context={"user_id": "u123"}
)

if result.blocked:
    print(f"Blocked by policy: {result.policy.reason}")

Verification

from moss_langgraph import verify_envelope

verify_result = verify_envelope(result.envelope)
if verify_result.valid:
    print(f"Signed by: {verify_result.subject}")

All Functions

Legacy API: Auto-Signing Decorator

The old decorator API is still available:

from langgraph.graph import StateGraph
from moss_langgraph import signed_node, SignedNodeFactory

# Wrap individual nodes
graph.add_node("step", signed_node(my_node, "moss:flow:step"))

# Or use factory for multiple nodes
factory = SignedNodeFactory("moss:flow:pipeline")
graph.add_node("step1", factory.wrap(step1_fn))
graph.add_node("step2", factory.wrap(step2_fn))

Enterprise Features

Links

• moss-sdk - Core MOSS SDK
• mosscomputing.com - Project site

License

This package is licensed under the Business Source License 1.1.

• Free for evaluation, testing, and development
• Free for non-production use
• Production use requires a MOSS subscription
• Converts to Apache 2.0 on January 25, 2030