jep-langgraph-adapter

JEP runtime adapter for LangGraph: replayable delegation and verifiable AI accountability semantics.

This package instruments LangGraph-style node callables without modifying LangGraph core. Wrapped node execution naturally emits a deterministic, hash-linked JEP accountability chain containing:

• Judgment Event
• Delegation Event
• Termination Event
• Verification Event

Each event records node_name, agent_id, tool_name, state_transition, authority_scope, and previous_event_hash.

Install

pip install -e .

LangGraph is optional for tests and examples because the adapter works at the callable-node boundary:

pip install -e '.[langgraph]'

Usage

from jep_langgraph_adapter import LangGraphEventAdapter

adapter = LangGraphEventAdapter(
    session_id="demo-session",
    agent_id="planner-agent",
    authority_scope={"tools": ["search"], "max_steps": 3},
)

def plan(state):
    return {**state, "plan": "call search"}

wrapped_plan = adapter.wrap_node(plan, node_name="plan")
next_state = wrapped_plan({"question": "What changed?"})
adapter.exporter().export_jsonl("session.jsonl")

For a StateGraph, add wrapped nodes through instrument_state_graph:

adapter.instrument_state_graph(graph, {"plan": plan, "answer": answer})

Replay CLI

jep-langgraph replay session.jsonl

The replay command validates deterministic event hashes, sequence numbers, and previous_event_hash links.

Components

• JEPNodeMiddleware: wraps sync or async LangGraph node callables.
• JEPExecutionTracer: records judgment, delegation, termination, and verification events.
• JEPReplayExporter: exports JSON/JSONL and validates replay chains.
• LangGraphEventAdapter: high-level facade for node and graph instrumentation.

Examples

• examples/multi_step_graph.py: multi-step graph execution.
• examples/sub_agent_delegation.py: sub-agent delegation chain.
• examples/tool_invocation_replay.py: tool invocation verification and replay.

Runtime and verification notes

See HARDENING.md for supported behavior, regression checks, and compatibility boundaries.