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Community exampleVerifiedAvailable2026-10-08

langgraph-jev 0.1.0

A community LangGraph and LangChain package that wraps Jev as a typed decision node with scoped state, confidence policies, and deterministic routing.

Install

pip install langgraph-jev

Server environment variables

TYPESAFE_API_KEY

Prerequisites

  • Python 3.11 or newer
  • langgraph-jev 0.1.0 pinned and tested in the application
  • A TypeSafe API key stored in the server environment
  • A human-review node for low-confidence outcomes

Implementation steps

  1. 1Install and pin the community package.
  2. 2Create a JevNode with typed questions and optional confidence thresholds.
  3. 3Use state_key and output_key when only part of the graph state should be sent or updated.
  4. 4Choose allow, human_review, or error as the low-confidence policy.
  5. 5Add the node to LangGraph and route its typed decision with application code.
  6. 6Use invoke or ainvoke through JevRunnable when integrating with LangChain.
Server example
from langgraph_jev import JevNode, choice, route_by_decision

jev = JevNode(
    state_key="structured_request",
    output_key="decision",
    questions={
        "work_type": choice(["bug", "support", "documentation"]),
    },
    thresholds={"work_type": 0.85},
    low_confidence="human_review",
)

def route_work(state):
    decision = state["decision"]
    if decision.requires_review:
        return "human_review"
    return route_by_decision(
        decision,
        field="work_type",
        routes={
            "bug": "coding_agent",
            "support": "support_agent",
            "documentation": "documentation_agent",
        },
        fallback="human_review",
    )

Production checks

  • This is a community package and is not an official TypeSafe or LangChain integration.
  • Close long-lived JevClient resources during application shutdown.
  • Keep TYPESAFE_API_KEY on the server and exclude state fields that are not required for the decision.
  • Calibrate every confidence threshold on representative workflow data.
  • Keep downstream routing deterministic and make side effects idempotent.

Limitations and verification notes

langgraph-jev 0.1.0 is a community-maintained adapter that calls the hosted Jev API. Package behavior, TypeSafe API behavior, and LangGraph compatibility can change independently, so pin and regression-test all three boundaries.

Related pages

Sources

This guide is independently maintained by Type Safe. Check the provider’s current documentation, versions, and terms before use.