LangChain in Supabase Edge Functions: Set up a RAG function

Understand the project

Practical overview

When it fits

Use it when you want a concrete TypeScript setup example for adding LangChain packages to a Supabase Edge Function and deploying that function.

Who it is for

Developers building with Supabase Edge Functions who need a documented way to import LangChain packages.
Developers prototyping serverless RAG or document-question-answering functions.

Documented uses

Initialize and start a Supabase project locally.
Create an Edge Function and configure LangChain package imports.
Deploy all Supabase Edge Functions or a specific function to a linked cloud project.

Before you choose

Requirements & limits

Docker is required to start the local Supabase project.
The import map pins specific package versions and uses esm.sh URLs for LangChain packages.
Deployment requires a link to a Supabase cloud project.
The guide does not document a complete document-ingestion workflow.

Check current requirements in the official documentation. Source-based guidance does not mean OpenViST has run or independently tested this project.

Source-based practical guide

Set up and deploy a Supabase Edge Function with LangChain imports

Initialize a Supabase project, create an Edge Function, configure the documented package imports, and deploy the function.

Before you start

Docker installed for starting the local Supabase project.
A Supabase cloud project linked before deployment.

Steps

Run the command below in the chosen project directory.
Documented command
```
npx supabase init
```
Run the command below, then create a function with the command below.
Documented command
```
npx supabase start
```
Documented command
```
npx supabase functions new 
```
Create import_map.json in the functions folder using the README's listed Supabase and LangChain package mappings; include trailing slashes for package submodules.
Deploy all functions with the command below, or deploy a named function with the command below.
Documented command
```
npx supabase functions deploy
```
Documented command
```
npx supabase functions deploy 
```

Expected outcome

A Supabase Edge Function set up with the documented LangChain-related package imports and deployed to the linked Supabase cloud project.

Guide limitations

The guide describes package setup for a basic RAG pipeline but does not provide a complete document-ingestion workflow.
Local project startup uses Docker, and deployment requires the project to be linked to Supabase cloud.

Documentation 1 ↗

COMPARE OPTIONS

Compare options for Retrieval-augmented applications

These projects document a common task and share a project role. This is a source-based comparison, not an execution benchmark or a guarantee of interchangeability.

Project	Documented purpose	Platform
LangChain in Supabase Edge Functions	Initialize and start a Supabase project locally.	Cloud, Server
Rag Powered AI Assistant Transforming Data Retrieval And Analysis Across The Web And Pdfs	Retrieve relevant passages from web and PDF content to answer a question.	Web
Fiftyone Multimodal Rag Plugin	Create a FiftyOne dataset from directories containing images, text files and PDFs	Cloud

Evidence and transparency

Sources & review

Official repository ↗

Source record details

Source availability: Active
Sources checked: 18 October 2026
Original website title: GreatHayat/supabase-edge-functions-rag · Official homepage title · retained in its source language

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LangChain in Supabase Edge Functions