PHP-RAG

An AI assistant ("chatbot") built with PHP, Solr (or other DB backend) and LLM of choice. Proof of concept mostly.

Idea

What is retrieval-augmented generation? | IBM

Installation

This project uses DDEV to manage the environment.

After installing DDEV, run:

ddev start
ddev composer i
cp env.example .env

If you are not using DDEV, you will need:

• PHP 8.1 with at least curl extension
• Composer
• Solr server
• Access to a LLM service

Configuration

.env / env.example has the following configuration options:

• SOLR_HOST - Hostname of Solr server
• SOLR_PORT - Port of Solr server
• SOLR_CORE - Name of the core of the Solr server
• ELASTIC_HOST - Hostname and port of Elastic server
• ELASTIC_API_KEY - API key of Elastic server
• ELASTIC_INDEX - Name of the index of the Elastic server
• CONTEXT_TOKEN_COUNT - Maximum token count to be included in LLM context
• REPLICATE_API_KEY - Replicate API key (if using Replicate LLM)
• REPLICATE_MODEL_VERSION - Hash of the model version used in Replicate (if using Replicate LLM)
• KOBOLDAI_HORDE_API_KEY - KoboldAI Horde API key (if using KoboldAI Horde LLM)
• OPENAI_API_KEY - OpenAI API key
• OPENAI_MODEL - Name of the model used in OpenAI query

Backend (database)

• Solr
• ElasticSearch

More backends (like MySQL or Sqlite) can be done easily, just implement the Krisseck\PhpRag\Backend\BackendInterface.

LLM

• OpenAI
• Replicate
• KoboldAI Horde

Replicate is the easiest to use, you can get a free API key on https://replicate.com/.

For Replicate, you need to provide the hash of the model version you will be using. You can get the hash from "Versions" tab on a model's page.

Demo

There's an example script in examples folder. To run it with DDEV:

ddev start
ddev ssh
cd examples
php chicago-prompt.php

Note that fetching the output can take a while on free APIs, so be patient. 🙂