Build a RAG application via VerticalAPI

from openai import OpenAI

client = OpenAI(
    base_url="https://api.verticalapi.com/v1",
    api_key="vapi_...",
    default_headers={"X-Provider-Key": "sk-ant-..."}
)

# 1. Embed query (Cohere via VerticalAPI)
query_emb = client.embeddings.create(
    model="embed-english-v3",
    input=user_question
).data[0].embedding

# 2. Vector search (your DB — pgvector, Pinecone, ...)
chunks = vector_db.search(query_emb, k=20)

# 3. Rerank (Cohere) and pick top 5
top_chunks = rerank(chunks, user_question)[:5]

# 4. Generate with citations
response = client.chat.completions.create(
    model="claude-sonnet-4-5",
    messages=[{
        "role": "user",
        "content": f"Answer using these sources:\n\n{top_chunks}\n\nQ: {user_question}"
    }]
)