# LOGIC.md — declarative reasoning contracts that compile to LangGraph StateGraph

**URL:** <https://forum.langchain.com/t/logic-md-declarative-reasoning-contracts-that-compile-to-langgraph-stategraph/3472>\
**Category:** LangGraph\
**Tags:** python-help\
**Created:** [April 20, 2026, 1:13pm UTC](https://forum.langchain.com/t/logic-md-declarative-reasoning-contracts-that-compile-to-langgraph-stategraph/3472 "2026-04-20T13:13:39Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![SingleSourceAI](https://yyz1.discourse-cdn.com/flex007/user_avatar/forum.langchain.com/singlesourceai/32/2825_2.png) [@SingleSourceAI](https://forum.langchain.com/u/SingleSourceAI)\
**Post date:** [April 20, 2026, 1:13pm UTC](https://forum.langchain.com/t/logic-md-declarative-reasoning-contracts-that-compile-to-langgraph-stategraph/3472/1 "2026-04-20T13:13:39Z")

</div>

Been building a declarative spec format for multi-agent reasoning, and the LangGraph adapter is the most developed integration. Posting here for feedback from people running StateGraph systems in production.

**What LOGIC.md is**

A YAML file that declares step DAGs, output contracts, quality gates, tool permissions, and fallback chains. Framework-agnostic, compiles to LangGraph today (CrewAI and AutoGen planned).

**Why this might matter for LangGraph users**

Right now, if you want StateGraph to enforce output contracts, quality gates, or tool permissions, you write it imperatively — validation logic in each node function, retry logic scattered across the graph. With LOGIC.md you declare it once:

yaml

```auto
contracts:
  outputs:
    sources: { type: array, items: { type: object } }
quality_gates:
  post_output:
    - check: "outputs.sources.length > 0"
      action: retry
      max_retries: 3

```

The adapter compiles this to StateGraph node definitions with:

- Type-validated state schemas

- Pre/post node hooks for contract enforcement

- Automatic retry logic for failed quality gates

- Per-node tool permission checks

- Fallback edge routing

typescript

```auto
import { compile_to_langgraph } from "@logic-md/adapters/langgraph";

const spec = parse(markdownContent);
const graph_builder = compile_to_langgraph(spec);
const graph = graph_builder.compile();
// graph is a LangGraph StateGraph with LOGIC.md contracts baked in

```

**Adapter state (honest)**

Proof of concept. Core node compilation works. Quality gates and tool permissions are stubbed. Needs real workflows to validate the API — I built it in isolation so there are almost certainly design issues a production LangGraph user would catch immediately.

**What I’m looking for feedback on**

1. Does the LOGIC.md data model fit how you actually build LangGraph workflows, or are there primitives missing?

2. For those running LangGraph at scale — what do you currently do for output contracts and quality gates? Imperative code, or something else?

3. Streaming: how should declarative contracts behave when reasoning happens incrementally? Open design question.

4. Are there LangGraph patterns you’d want the adapter tested against?

**Links**

- Repo: [https://github.com/SingularityAI-Dev/logic-md](https://github.com/SingularityAI-Dev/logic-md)

- LangGraph adapter: [https://github.com/SingularityAI-Dev/logic-md/tree/main/adapters/langgraph](https://github.com/SingularityAI-Dev/logic-md/tree/main/adapters/langgraph)

- Spec: [https://github.com/SingularityAI-Dev/logic-md/blob/main/docs/SPEC.md](https://github.com/SingularityAI-Dev/logic-md/blob/main/docs/SPEC.md)

Happy to pair with anyone who wants to push the adapter forward, or take feedback issues on the repo.