Aug 16, 2025
Compare AI RAG Tooling (2025)
By Core API Team
RAGRetrievalEmbeddings2025
Compare AI RAG Tooling (2025)
RAG systems combine embedding, storage, and retrieval with LLM reasoning. This guide compares popular stacks and shows how to wire calls through a unified API.
At‑a‑glance
| Stack | Strengths | Trade‑offs | Best for | 
|---|---|---|---|
| OpenAI + pgvector | Simple, reliable, SQL ecosystem | Managed Postgres costs | Product docs, app search | 
| OpenAI/Ada + Pinecone | Scalable vector DB, hybrid search | Vendor lock‑in | Large knowledge bases | 
| Cohere/Embed + Weaviate | Filters, hybrid, OSS option | Ops overhead (self‑host) | Privacy‑sensitive data | 
| Voyage/Embed + Milvus | High‑perf, cost‑effective | Infra complexity | Big embeddings at scale | 
Feature comparison
| Capability | OpenAI + pgvector | Pinecone | Weaviate | Milvus | 
|---|---|---|---|---|
| Hybrid (BM25+Vec) | ✅ (with ext.) | ✅ | ✅ | ✅ (via stack) | 
| Metadata filters | ✅ | ✅ | ✅ | ✅ | 
| Multi‑tenant | ✅ | ✅ | ✅ | ✅ | 
| Managed option | ✅ | ✅ | ✅ (Cloud) | ✅ (Cloud) | 
Unified API examples
Create embeddings — JavaScript
import axios from "axios";
const res = await axios.post(
  "https://api.coreapi.com/v1/openai/embeddings",
  {
    model: "text-embedding-3-large",
    input: [
      "RAG connects your data to an LLM via retrieval.",
      "Use chunking and metadata to improve recall.",
    ],
  },
  { headers: { Authorization: `Bearer ${process.env.CORE_API_KEY}` } }
);
console.log(res.data);
Retrieve → answer — Python
import requests, os
# 1) embed the query
e = requests.post(
    "https://api.coreapi.com/v1/openai/embeddings",
    json={"model": "text-embedding-3-large", "input": "How do fallbacks work?"},
    headers={"Authorization": f"Bearer {os.environ['CORE_API_KEY']}"},
).json()
query_vec = e["data"][0]["embedding"]
# 2) search your vector DB (pseudo‑code)
# matches = vector_db.search(query_vec, top_k=5, filter={"tag": "docs"})
contexts = [m["text"] for m in []]  # replace with results
# 3) ask LLM with contexts
r = requests.post(
    "https://api.coreapi.com/v1/openai/chat/completions",
    json={
        "model": "gpt-4o-mini",
        "messages": [
            {"role": "system", "content": "Answer with provided context."},
            {"role": "user", "content": f"Context: {'\n'.join(contexts)}\nQuestion: How do fallbacks work?"},
        ],
    },
    headers={"Authorization": f"Bearer {os.environ['CORE_API_KEY']}"},
)
print(r.json())
Implementation tips
- Chunk by structure (headings, sections) not only tokens.
 - Store metadata (source, section, updated_at) for filters and recency.
 - Evaluate with golden‑set queries; watch recall@k and answer utility.