# Why Vector Search Breaks Production: Building a 2-Hop Relational Context Engine in Sanity

> Source: <https://dev.to/rajan_mishra_a9f78ad216b4/why-vector-search-breaks-production-building-a-2-hop-relational-context-engine-in-sanity-134c>
> Published: 2026-09-26 00:09:19+00:00

*This is a submission for the [Sanity Challenge, Path Two: Build a Knowledge Base or Context Engine](https://dev.to/challenges/sanity-2026-09-16).*

The AI community has spent the last three years building Retrieval-Augmented Generation (RAG) on top of vector similarity search (Pinecone, Chroma, pgvector). For prose and chat applications, cosine similarity on text chunks works well.

**For engineering infrastructure, vector search is a recipe for outages.**

Vector databases compress text into high-dimensional vectors. In doing so, they lose:

`Service A v4` strictly requires `Service B >= v3.0`.
For **Path Two**, we built a **deterministic 2-hop relational context engine** on top of the **Sanity Content Lake**. Instead of flattening our documentation into vectors, we model organizational knowledge as a structured, queryable graph of microservices, version constraints, policies, and semantic relationships.

When an engineer or autonomous coding assistant asks:

*"Can I upgrade payment service from v2 to v4 tonight?"*

Our engine doesn't guess with embeddings. It executes deterministic GROQ graph traversals that surface the hidden dependency chain, detect cluster pod collisions, and resolve documentation contradictions with 100% mathematical precision.

We designed 18 interconnected documents in Sanity (`70rd1u6b`) across three core schema types:

`component`` versionConstraint``targetComponent`, `requiredComponent`, `operator`, `version`, `criticality`).` knowledgeEntry``contradicts`: Directed references pointing to documents this entry intentionally overrides.`isExceptionOf`: Encodes conditional policy exemptions (e.g., emergency security hotfixes).`authorityLevel`: An integer (1–10) providing deterministic arbitration when documentation drifts.
Here is the core GROQ query executed by our context engine to resolve 2-hop dependency chains in a single database round-trip:

```
*[_type == "component" && name == $componentName][0] {
  name,
  currentVersion,
  "hop1_constraints": *[_type == "versionConstraint" && targetComponent._ref == ^._id] {
    "requiredServiceName": requiredComponent->name,
    "requiredClusterVersion": requiredComponent->currentVersion,
    operator,
    version,
    criticality
  },
  "drift_audit": *[_type == "knowledgeEntry" && references(^._id)] | order(authorityLevel desc) {
    title,
    authorityLevel,
    sourceType,
    "contradicts": contradicts[]->title,
    "isExceptionOf": isExceptionOf->title,
    body
  }
}
```

This single query traverses:

`Payment Service`).` requires Payment SDK >= v3.0.0`).` Payment SDK v2.4.1`).
We benchmarked our Sanity Context Engine against a standard vector similarity search (simulating Pinecone / LangChain RAG) over the exact same 18 documents.

**User Query:** *"Can I upgrade payment service from v2 to v4 tonight?"*

| Evaluation Metric | Naive Vector Search (Pinecone/RAG) | SHIPCHECK Sanity Context Engine | 
|---|---|---|
| **Verdict** | ❌ `SAFE TO SHIP`*(False Positive)* | ✅ `DO NOT SHIP YET`*(Hard Blocker)* | 
| **Why it reached this result** | Matched keywords "payment service" and "upgrade". Found documents saying v4 has great new features. Completely missed the SDK requirement because the word "SDK" was not in the prompt. | Traversed Hop-1 to find `Payment SDK >= v3.0.0` . Traversed Hop-2 to find cluster running`v2.4.1` . Detected collision immediately. | 
| **Documentation Drift** | Hallucinated a merge of XML and JSON specs. | Resolved by authority: Release Notes (Auth 10) explicitly supersedes Stale Wiki (Auth 4). | 
| **Production Outcome** | **P0 Outage:** Token HMAC verification failures across all checkout pods. | **0 Outages:** Outage prevented before code merged. | 

Our engine supports **in-memory graph mutation**. When an engineer clicks *"Simulate Fix"*, the engine re-evaluates the GROQ traversal with `Payment SDK v3.1.0` applied to the cluster representation. The 2-hop collision clears, all constraints evaluate to green, and the verdict live-flips to `SAFE TO SHIP`.

`lib/engine/groqTraversal.ts`` sanity/schemaTypes/``lib/engine/naiveSearchStub.ts`
When building this context engine for AI coding assistants (via MCP JSON-RPC), we noticed:

`70rd1u6b`
`production`
`2024-01-01`
*Built with ❤️ for the Sanity Context MCP Hackathon (Path Two).*