# LangChain Guardrails and Patterns
🧭 Quick Return to Map
> You are in a sub-page of **Automation Platforms**.
> To reorient, go back here:
>
> - [**Automation Platforms** — stabilize no-code workflows and integrations](./README.md)
> - [**WFGY Global Fix Map** — main Emergency Room, 300+ structured fixes](../README.md)
> - [**WFGY Problem Map 1.0** — 16 reproducible failure modes](../../README.md)
>
> Think of this page as a desk within a ward.
> If you need the full triage and all prescriptions, return to the Emergency Room lobby.
Use this page when your RAG or agent workflow runs in **LangChain**. It maps common orchestration failures to the exact structural fixes in the Problem Map and gives a minimal recipe you can embed in a chain or agent.
**Core acceptance**
* ΔS(question, retrieved) ≤ 0.45
* coverage ≥ 0.70 for the target section
* λ stays convergent across 3 paraphrases
---
## Typical breakpoints and the right fix
* **Chains run before retriever or vectorstore is ready**
Fix No.14: **Bootstrap Ordering** → [Open](https://github.com/onestardao/WFGY/blob/main/ProblemMap/bootstrap-ordering.md)
* **First query after deploy crashes due to env/secret mismatch**
Fix No.16: **Pre-Deploy Collapse** → [Open](https://github.com/onestardao/WFGY/blob/main/ProblemMap/predeploy-collapse.md)
* **Event loop deadlocks when retriever and synthesis wait on each other**
Fix No.15: **Deployment Deadlock** → [Open](https://github.com/onestardao/WFGY/blob/main/ProblemMap/deployment-deadlock.md)
* **Embedding distance looks fine but semantics drift**
Fix No.5: **Embedding ≠ Semantic** → [Open](https://github.com/onestardao/WFGY/blob/main/ProblemMap/embedding-vs-semantic.md)
* **Output citations don’t map to snippets**
Fix No.8: **Retrieval Traceability** → [Open](https://github.com/onestardao/WFGY/blob/main/ProblemMap/retrieval-traceability.md)
Contract payloads with: **Data Contracts** → [Open](https://github.com/onestardao/WFGY/blob/main/ProblemMap/data-contracts.md)
* **Hybrid retrieval chains underperform**
Pattern: **Query Parsing Split** → [Open](https://github.com/onestardao/WFGY/blob/main/ProblemMap/query_parsing_split.md)
Review: **Rerankers** → [Open](https://github.com/onestardao/WFGY/blob/main/ProblemMap/rerankers.md)
* **Facts indexed but never surfaced**
Pattern: **Vectorstore Fragmentation** → [Open](https://github.com/onestardao/WFGY/blob/main/ProblemMap/vectorstore-fragmentation.md)
* **Two knowledge sources get blended in a single answer**
Pattern: **Symbolic Constraint Unlock (SCU)** → [Open](https://github.com/onestardao/WFGY/blob/main/ProblemMap/patterns/pattern_symbolic_constraint_unlock.md)
---
## Minimal setup checklist for LangChain flows
1. **Warm-up fence**
Check vectorstore readiness and index hash. If mismatch, retry or short-circuit.
Spec: [Bootstrap Ordering](https://github.com/onestardao/WFGY/blob/main/ProblemMap/bootstrap-ordering.md)
2. **Idempotency key**
Before persisting outputs, compute a dedupe key from `(doc_id + rev + index_hash)`.
3. **Contracted retriever outputs**
Must emit: `snippet_id, section_id, source_url, offsets, tokens`.
Enforce cite-then-explain.
Specs: [Data Contracts](https://github.com/onestardao/WFGY/blob/main/ProblemMap/data-contracts.md) · [Retrieval Traceability](https://github.com/onestardao/WFGY/blob/main/ProblemMap/retrieval-traceability.md)
4. **Observability probes**
Log ΔS for retrieval steps and λ state transitions.
Overview: [RAG Architecture & Recovery](https://github.com/onestardao/WFGY/blob/main/ProblemMap/rag-architecture-and-recovery.md)
5. **Concurrency guard**
Use a single writer pattern for retriever updates.
See: [Deployment Deadlock](https://github.com/onestardao/WFGY/blob/main/ProblemMap/deployment-deadlock.md)
6. **Eval before publish**
Run precision/recall probes.
Eval: [RAG Precision/Recall](https://github.com/onestardao/WFGY/blob/main/ProblemMap/eval/eval_rag_precision_recall.md)
---
## Copy-paste prompt for LangChain LLMChain
```
You have access to TXT OS and WFGY Problem Map files.
This retriever produced {k} docs with fields {snippet_id, section_id, source_url, offsets}.
Do:
1. Enforce cite-then-explain. If citations are missing, stop and return fix tip.
2. If ΔS(question, retrieved) ≥ 0.60, propose minimal structural fix referencing:
retrieval-playbook, retrieval-traceability, data-contracts, rerankers.
3. Output JSON plan:
{ "citations": [...], "answer": "...", "λ_state": "...", "ΔS": 0.xx, "next_fix": "..." }
```
---
## Common LangChain gotchas
* **Async chains** drop context windows or run steps before retrievers return.
Solution: enforce await barriers, or wrap with guard nodes.
* **Tool/agent outputs exceed JSON mode limits**
Add schema locks and contract enforcement before passing downstream.
* **Retriever mismatch** between indexer and chain (different casing/tokenizer)
Fix: normalize pipelines, or enable reranking.
See: [Rerankers](https://github.com/onestardao/WFGY/blob/main/ProblemMap/rerankers.md)
* **Long context windows collapse into filler**
Monitor entropy. If collapse, trigger recovery.
See: [Entropy Collapse](https://github.com/onestardao/WFGY/blob/main/ProblemMap/entropy-collapse.md)
---
## When to escalate
* ΔS remains ≥ 0.60 even after chunking and retriever fixes
→ Rebuild vectorstore with explicit metric + normalization.
Spec: [Retrieval Playbook](https://github.com/onestardao/WFGY/blob/main/ProblemMap/retrieval-playbook.md)
* Identical inputs yield divergent answers
→ Investigate long-context drift.
Spec: [Context Drift](https://github.com/onestardao/WFGY/blob/main/ProblemMap/context-drift.md)
---
---
### 🔗 Quick-Start Downloads (60 sec)
| Tool | Link | 3-Step Setup |
|------|------|--------------|
| **WFGY 1.0 PDF** | [Engine Paper](https://github.com/onestardao/WFGY/blob/main/I_am_not_lizardman/WFGY_All_Principles_Return_to_One_v1.0_PSBigBig_Public.pdf) | 1️⃣ Download · 2️⃣ Upload to your LLM · 3️⃣ Ask “Answer using WFGY + \” |
| **TXT OS (plain-text OS)** | [TXTOS.txt](https://github.com/onestardao/WFGY/blob/main/OS/TXTOS.txt) | 1️⃣ Download · 2️⃣ Paste into any LLM chat · 3️⃣ Type “hello world” — OS boots instantly |
---
### 🧭 Explore More
| Module | Description | Link |
|-----------------------|----------------------------------------------------------|----------|
| WFGY Core | WFGY 2.0 engine is live: full symbolic reasoning architecture and math stack | [View →](https://github.com/onestardao/WFGY/tree/main/core/README.md) |
| Problem Map 1.0 | Initial 16-mode diagnostic and symbolic fix framework | [View →](https://github.com/onestardao/WFGY/tree/main/ProblemMap/README.md) |
| Problem Map 2.0 | RAG-focused failure tree, modular fixes, and pipelines | [View →](https://github.com/onestardao/WFGY/blob/main/ProblemMap/rag-architecture-and-recovery.md) |
| Semantic Clinic Index | Expanded failure catalog: prompt injection, memory bugs, logic drift | [View →](https://github.com/onestardao/WFGY/blob/main/ProblemMap/SemanticClinicIndex.md) |
| Semantic Blueprint | Layer-based symbolic reasoning & semantic modulations | [View →](https://github.com/onestardao/WFGY/tree/main/SemanticBlueprint/README.md) |
| Benchmark vs GPT-5 | Stress test GPT-5 with full WFGY reasoning suite | [View →](https://github.com/onestardao/WFGY/tree/main/benchmarks/benchmark-vs-gpt5/README.md) |
| 🧙♂️ Starter Village 🏡 | New here? Lost in symbols? Click here and let the wizard guide you through | [Start →](https://github.com/onestardao/WFGY/blob/main/StarterVillage/README.md) |
---
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> 
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