---
title: "Deploy LangServe RAG API + pgvector"
description: "LangServe RAG API with FastAPI, Postgres, pgvector, and auth."
category: "AI/ML"
url: https://railway.com/deploy/langserve-pgvector-rag
---

# Deploy LangServe RAG API + pgvector

LangServe RAG API with FastAPI, Postgres, pgvector, and auth.

**[Deploy LangServe RAG API + pgvector on Railway](https://railway.com/template/langserve-pgvector-rag)**

- **Creator:** leodev
- **Category:** AI/ML

## Template content

### langserve

- **Image:** python:3.12-slim
- **Start command:** `/bin/sh -c 'set -eu; mkdir -p /app; echo import hashlib
import math
import os
import uuid
from typing import Any

import psycopg
from fastapi import Depends, FastAPI, Header, HTTPException
from langchain_core.runnables import RunnableLambda
from langserve import add_routes
from psycopg.types.json import Jsonb
from pydantic import BaseModel, Field


DATABASE_URL = os.environ["DATABASE_URL"]
EMBEDDING_DIMENSIONS = int(os.getenv("EMBEDDING_DIMENSIONS", "64"))
COLLECTION = os.getenv("LANGSERVE_COLLECTION", "railway_docs")
REQUIRE_API_KEY = os.getenv("REQUIRE_API_KEY", "true").lower() == "true"
APP_API_KEY = os.getenv("APP_API_KEY", "")
OPENAI_API_KEY = os.getenv("OPENAI_API_KEY", "")
OPENAI_MODEL = os.getenv("OPENAI_MODEL", "gpt-4.1-mini")


class IngestRequest(BaseModel):
  text: str = Field(min_length=1)
  metadata: dict[str, Any] = Field(default_factory=dict)


class SearchRequest(BaseModel):
  query: str = Field(min_length=1)
  k: int = Field(default=4, ge=1, le=12)


class RagInput(BaseModel):
  question: str = Field(min_length=1)
  k: int = Field(default=4, ge=1, le=12)


class RagOutput(BaseModel):
  answer: str
  used_llm: bool
  contexts: list[dict[str, Any]]


def require_api_key(authorization: str | None = Header(default=None)) -> None:
  if not REQUIRE_API_KEY:
    return
  if not APP_API_KEY:
    raise HTTPException(status_code=500, detail="APP_API_KEY is required when REQUIRE_API_KEY=true")
  if authorization != f"Bearer {APP_API_KEY}":
    raise HTTPException(status_code=401, detail="Missing or invalid bearer token")


def embedding_for(text: str) -> list[float]:
  vector = [0.0] * EMBEDDING_DIMENSIONS
  for token in text.lower().split():
    digest = hashlib.sha256(token.encode("utf-8")).digest()
    index = int.from_bytes(digest[:4], "big") % EMBEDDING_DIMENSIONS
    sign = 1.0 if digest[4] % 2 == 0 else -1.0
    vector[index] += sign
  norm = math.sqrt(sum(value * value for value in vector)) or 1.0
  return [round(value / norm, 6) for value in vector]


def vector_literal(values: list[float]) -> str:
  return "[" + ",".join(str(value) for value in values) + "]"


def connect() -> psycopg.Connection:
  return psycopg.connect(DATABASE_URL)


def ensure_schema() -> None:
  with connect() as conn:
    with conn.cursor() as cur:
      cur.execute("CREATE EXTENSION IF NOT EXISTS vector")
      cur.execute(
        f"""
        CREATE TABLE IF NOT EXISTS documents (
          id uuid PRIMARY KEY,
          collection text NOT NULL,
          content text NOT NULL,
          metadata jsonb NOT NULL DEFAULT '{{}}'::jsonb,
          embedding vector({EMBEDDING_DIMENSIONS}) NOT NULL,
          created_at timestamptz NOT NULL DEFAULT now()
        )
        """
      )
      cur.execute("CREATE INDEX IF NOT EXISTS documents_collection_idx ON documents (collection)")
    conn.commit()


def search_documents(query: str, k: int) -> list[dict[str, Any]]:
  ensure_schema()
  query_vector = vector_literal(embedding_for(query))
  with connect() as conn:
    with conn.cursor() as cur:
      cur.execute(
        """
        SELECT id::text, content, metadata, 1 - (embedding <=> %s::vector) AS score
        FROM documents
        WHERE collection = %s
        ORDER BY embedding <=> %s::vector
        LIMIT %s
        """,
        (query_vector, COLLECTION, query_vector, k),
      )
      return [
        {"id": row[0], "text": row[1], "metadata": row[2], "score": float(row[3])}
        for row in cur.fetchall()
      ]


def ingest_document(payload: IngestRequest) -> dict[str, str]:
  ensure_schema()
  document_id = uuid.uuid4()
  with connect() as conn:
    with conn.cursor() as cur:
      cur.execute(
        """
        INSERT INTO documents (id, collection, content, metadata, embedding)
        VALUES (%s, %s, %s, %s, %s::vector)
        """,
        (
          document_id,
          COLLECTION,
          payload.text,
          Jsonb(payload.metadata),
          vector_literal(embedding_for(payload.text)),
        ),
      )
    conn.commit()
  return {"id": str(document_id)}


def answer_question(payload: RagInput | dict[str, Any]) -> RagOutput:
  if isinstance(payload, dict):
    payload = RagInput.model_validate(payload)

  contexts = search_documents(payload.question, payload.k)
  context_text = "\n\n".join(f"- {item['text']}" for item in contexts) or "No matching context found."
  prompt = (
    "Answer the question using only the retrieved context. "
    "If the context is insufficient, say what is missing.\n\n"
    f"Question: {payload.question}\n\nContext:\n{context_text}"
  )

  if OPENAI_API_KEY and not OPENAI_API_KEY.startswith("REPLACE_"):
    from langchain_openai import ChatOpenAI

    answer = ChatOpenAI(model=OPENAI_MODEL, temperature=0).invoke(prompt).content
    return RagOutput(answer=answer, used_llm=True, contexts=contexts)

  answer = (
    "OPENAI_API_KEY is not configured, so this starter returned retrieved context only.\n\n"
    f"{context_text}"
  )
  return RagOutput(answer=answer, used_llm=False, contexts=contexts)


app = FastAPI(
  title="LangServe pgvector RAG starter",
  version="1.0.0",
  description="A Railway-ready LangServe starter with Postgres/pgvector ingestion and retrieval.",
)


@app.on_event("startup")
def startup() -> None:
  ensure_schema()


@app.get("/")
def root() -> dict[str, str]:
  return {"service": "langserve-pgvector", "docs": "/docs", "health": "/health", "rag": "/rag/invoke"}


@app.get("/health")
def health() -> dict[str, Any]:
  ensure_schema()
  with connect() as conn:
    with conn.cursor() as cur:
      cur.execute("SELECT count(*) FROM documents WHERE collection = %s", (COLLECTION,))
      count = cur.fetchone()[0]
  return {"ok": True, "collection": COLLECTION, "documents": count}


@app.post("/ingest", dependencies=[Depends(require_api_key)])
def ingest(payload: IngestRequest) -> dict[str, str]:
  return ingest_document(payload)


@app.post("/search", dependencies=[Depends(require_api_key)])
def search(payload: SearchRequest) -> dict[str, Any]:
  return {"results": search_documents(payload.query, payload.k)}


rag_runnable = RunnableLambda(answer_question).with_types(input_type=RagInput, output_type=RagOutput)
add_routes(app, rag_runnable, path="/rag", dependencies=[Depends(require_api_key)])
 | base64 -d > /app/main.py; cd /app; python -m pip install --no-cache-dir fastapi==0.115.14 uvicorn[standard]==0.35.0 langserve==0.3.1 langchain-core==0.3.68 langchain-openai==0.3.27 psycopg[binary]==3.2.9 pgvector==0.4.1 pydantic==2.11.7 sse-starlette==2.4.1; exec python -m uvicorn main:app --host 0.0.0.0 --port "${PORT:-8000}"'`
- **Health check:** /health
- **Public domain:** Yes

### postgres

- **Image:** pgvector/pgvector:pg17

## Documentation

# Deploy and Host LangServe RAG API + pgvector on Railway

Run a production-shaped LangServe/FastAPI starter with Postgres, pgvector, health checks, ingest/search routes, and API-key protection.

## About Hosting LangServe RAG API + pgvector on Railway

- `langserve`: public FastAPI/LangServe service
- `postgres`: private Postgres database with pgvector
- `/health`, `/ingest`, `/search`, and `/rag/invoke` endpoints
- Generated API key for protected write/invoke routes
- No bundled model provider key

## Why Deploy LangServe RAG API + pgvector on Railway

The published template deploy test created `langserve` and `postgres`; both reached `SUCCESS`; `/health`, `/ingest`, and `/rag/invoke` returned HTTP `200`; and vector search still found the ingested document after restarting `langserve`.

This is a useful RAG API starter, not a novelty prompt demo.

## Common Use Cases

- RAG API prototypes
- Private document search starters
- LangServe evaluation environments
- pgvector integration tests
- AI backend starter services

## Dependencies for LangServe RAG API + pgvector Hosting

The app requires Postgres with pgvector for document storage and vector search. Model provider keys are intentionally not bundled, and should be supplied by the deployer when generated answers are needed.

### Deployment Dependencies

- `DATABASE_URL`: private Postgres connection string
- `APP_API_KEY`: generated bearer token for protected endpoints
- `OPENAI_API_KEY`: optional deployer-provided provider key
- `OPENAI_MODEL`: chat model to use when a provider key is supplied

## After Deploy

1. Set the model provider key your app needs.
2. Call `/health`.
3. Ingest a small test document.
4. Call `/search` or `/rag/invoke` with the generated API key.

## Support Checklist

If a deploy fails, include `langserve` and `postgres` deployment IDs, the `/health` response, and logs mentioning pgvector, database setup, or API key validation.


## Similar templates

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- [Hermes Agent | OpenClaw Alternative with Dashboard](https://railway.com/deploy/hermes-agent-or-openclaw-alternative-wit) — Self-Hosted Hermes AI Agent for Telegram, Discord & Slack

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