# Chunking to Embedding Contract — Guardrails and Fix Pattern
🧭 Quick Return to Map
> You are in a sub-page of **RAG_VectorDB**.
> To reorient, go back here:
>
> - [**RAG_VectorDB** — vector databases for retrieval and grounding](./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 **retrieval fails because the chunk schema is not aligned with the embedding ingestion contract**.
If the retriever expects fields that were never embedded, or chunks omit IDs/offsets/anchors, then citations drift and ΔS rises.
---
## Open these first
- Visual map and recovery: [RAG Architecture & Recovery](https://github.com/onestardao/WFGY/blob/main/ProblemMap/rag-architecture-and-recovery.md)
- Snippet and citation schema: [data-contracts.md](https://github.com/onestardao/WFGY/blob/main/ProblemMap/data-contracts.md)
- Retrieval traceability: [retrieval-traceability.md](https://github.com/onestardao/WFGY/blob/main/ProblemMap/retrieval-traceability.md)
- Chunking checklist: [chunking-checklist.md](https://github.com/onestardao/WFGY/blob/main/ProblemMap/chunking-checklist.md)
---
## Core acceptance
- Every chunk has `chunk_id`, `section_id`, `source_url`, `offsets`, `tokens`.
- Embedding index was built from the same schema as retrieval contract.
- ΔS(question, retrieved) ≤ 0.45 across 3 paraphrases.
- Coverage ≥ 0.70 to the target section.
---
## Typical breakpoints and the right fix
- **Missing fields** in ingestion (e.g., no `section_id`)
→ Enforce [data-contracts.md](https://github.com/onestardao/WFGY/blob/main/ProblemMap/data-contracts.md).
- **Different schema for ingest vs retrieve**
→ Corpus ingested raw text, retriever expects chunk JSON → rebuild with schema.
- **Offsets not tracked**
→ Cannot map back to original document → enforce `offsets` at ingest.
- **Tokenizer drift**
→ Chunk IDs differ between preprocessing runs → use [chunking-checklist.md](https://github.com/onestardao/WFGY/blob/main/ProblemMap/chunking-checklist.md).
---
## Fix in 60 seconds
1. **Check ingestion schema**
Compare the fields stored in the index with the fields expected in retrieval.
2. **Align contracts**
Define `chunk = {chunk_id, section_id, source_url, offsets, tokens, text}`.
Enforce that this exact object is used both in ingestion and retrieval.
3. **Rebuild index if misaligned**
If fields differ, re-ingest corpus with enforced schema.
---
## Copy-paste schema
```json
{
"chunk_id": "uuid-v4",
"section_id": "doc-23-sec-7",
"source_url": "https://example.com/doc23",
"offsets": [120, 320],
"tokens": 512,
"text": "...."
}
````
Target: retriever always returns this schema, LLM consumes directly.
---
## Common gotchas
* Only `text` embedded, no IDs → cannot trace back → citations drift.
* Chunk boundaries not logged → hallucinations reappear.
* JSON schema updated mid-deploy → index mismatch.
---
### 🔗 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
| Layer | Page | What it’s for |
| --- | --- | --- |
| ⭐ Proof | [WFGY Recognition Map](/recognition/README.md) | External citations, integrations, and ecosystem proof |
| ⚙️ Engine | [WFGY 1.0](/legacy/README.md) | Original PDF tension engine and early logic sketch (legacy reference) |
| ⚙️ Engine | [WFGY 2.0](/core/README.md) | Production tension kernel for RAG and agent systems |
| ⚙️ Engine | [WFGY 3.0](/TensionUniverse/EventHorizon/README.md) | TXT based Singularity tension engine (131 S class set) |
| 🗺️ Map | [Problem Map 1.0](/ProblemMap/README.md) | Flagship 16 problem RAG failure taxonomy and fix map |
| 🗺️ Map | [Problem Map 2.0](/ProblemMap/wfgy-rag-16-problem-map-global-debug-card.md) | Global Debug Card for RAG and agent pipeline diagnosis |
| 🗺️ Map | [Problem Map 3.0](/ProblemMap/wfgy-ai-problem-map-troubleshooting-atlas.md) | Global AI troubleshooting atlas and failure pattern map |
| 🧰 App | [TXT OS](/OS/README.md) | .txt semantic OS with fast bootstrap |
| 🧰 App | [Blah Blah Blah](/OS/BlahBlahBlah/README.md) | Abstract and paradox Q&A built on TXT OS |
| 🧰 App | [Blur Blur Blur](/OS/BlurBlurBlur/README.md) | Text to image generation with semantic control |
| 🏡 Onboarding | [Starter Village](/StarterVillage/README.md) | Guided entry point for new users |
If this repository helped, starring it improves discovery so more builders can find the docs and tools.
[](https://github.com/onestardao/WFGY)