Server Configuration

Quick Setup with copy-env
From the backend/ directory, scaffold the runtime env file in one command:

pnpm install
pnpm run copy-env

This reads copy-env-config.json and copies src/.env.example to src/.env. The backend loads src/.env at startup; fill in the generated placeholders before running the server. Docker Compose can additionally load backend/.env when that file exists.

Configuration Overview Table

Feature / Setting	Option / Key	Where to Toggle	Default Value
HTTP Listening Port	`PORT`	`backend/src/.env` or Compose	`5000`
CORS Origin Allowance	`CLIENT_URL`	`backend/src/.env` or Compose	`http://localhost:3000`
PostgreSQL Connection String	`DATABASE_URL`	`backend/src/.env` or Compose	Required
Redis Broker URI	`REDIS_URL`	`backend/src/.env` or Compose	`redis://localhost:6379`
Default Fallback AI Model	`BASE_MODEL`	`backend/src/.env` or Compose	Provider-specific
Platform AI Provider API Key	`AI_API_KEY`	`backend/src/.env` or Compose	Unset / None
Custom AI Endpoint Gateway	`AI_BASE_URL`	`backend/src/.env` or Compose	Provider-specific
OpenAI Client Invocation Method	`OPEN_AI_INTERFACE`	`backend/src/.env` or Compose	`chat`
Email Delivery (Resend API)	`RESEND_API_KEY`	`backend/src/.env` or Compose	Unset / None
GitHub Integration	`GITHUB_ACESSES_TOKEN`, `GITHUB_APP_*`	`backend/src/.env` or Compose	Unset / None
Encryption & Auth	`API_ENCRYPTION_KEY`, `BETTER_AUTH_URL`	`backend/src/.env` or Compose	Unset / None
Per-User Free Spend Allowance	`perUserSpendLimit`	`backend/src/config/config.ts`	`$0.30` USD
Platform Free Model Pricing	`goBetterFreeModels`	`backend/src/config/config.ts`	Model price map
Platform InceptionLabs Gateway	`goBetterBaseUrl`	`backend/src/config/config.ts`	InceptionLabs gateway URL

Detailed Configuration Breakdown

Where to Get Each Backend Value

Create the backend file from backend/src/.env.example and replace every YOUR_VALUE_HERE placeholder. Keep this file private: backend environment values are secrets unless marked public configuration.

Variable	Required	How to acquire it
`PORT`	Yes	Use `5000` locally. In a hosted container, use the port required by the platform and keep the Compose mapping in sync. Public configuration.
`BASE_MODEL`	Yes	Copy the model ID from the AI provider’s model catalog, for example `mercury-2` for InceptionLabs.
`AI_BASE_URL`	Yes	Copy the OpenAI-compatible API base URL from the provider’s API documentation.
`AI_API_KEY`	Yes	Create an API key in the selected AI provider’s dashboard. Store it only in the backend environment.
`OPEN_AI_INTERFACE`	Yes	Use `chat` for chat-completions providers. Use `responses` only when the selected provider supports it.
`GITHUB_ACESSES_TOKEN`	Optional	This is the current spelling in the template. The current backend does not read it directly; prefer the GitHub App values below.
`REDIS_URL`	Yes	Create a Redis database with Redis Cloud, Upstash, Railway, or locally. Copy its full connection URI.
`DATABASE_URL`	Yes	Create a PostgreSQL database with Neon, Supabase, Railway, or locally. Copy its connection string and keep SSL parameters intact.
`API_ENCRYPTION_KEY`	Yes	Generate a unique 32-byte secret encoded as base64. Do not reuse a password or commit it.
`CLIENT_URL`	Yes	Set this to the browser origin allowed to call the API, such as `http://localhost:3000` or your deployed frontend URL. Public configuration.
`API_BASE_URL`	Yes for GitHub callbacks	Set this to the public backend origin, such as `http://localhost:5000` or `https://api.example.com`. Public configuration.
`BETTER_AUTH_URL`	Yes for hosted auth	Set this to the backend’s public origin. It normally matches `API_BASE_URL`. Public configuration.
`RESEND_API_KEY`	Yes for email	Create an API key in the Resend dashboard. Verify the sending domain and sender address first.
`GITHUB_APP_CLIENT_ID`	Yes for GitHub login	Create or open a GitHub OAuth App and copy its Client ID. Set its callback URL to `<API_BASE_URL>/auth/github/callback`.
`GITHUB_APP_CLIENT_SECRET`	Yes for GitHub login	Copy or generate the Client secret from the same GitHub OAuth App. Store it only in the backend environment.
`GITHUB_APP_SLUG`	Yes for GitHub App links	Copy the slug from the GitHub App installation URL or app settings.

Generate an Encryption Key

node -e "console.log(require('crypto').randomBytes(32).toString('base64'))"

Backend Secrets and Rotation

Never place AI_API_KEY, DATABASE_URL, REDIS_URL, RESEND_API_KEY, GitHub secrets, or API_ENCRYPTION_KEY in frontend files, source control, Docker images, or public issue reports. If a secret is exposed, revoke it at the provider immediately and replace it in the backend environment.

1. Networking & CORS

`PORT`

Location: backend/.env
Description: Defines which port the server listens on upon startup (app.listen(port)).
Example:
PORT=5000

`CLIENT_URL`

Location: backend/src/.env or the Compose environment

Description: Configured in Express’s cors() middleware in backend/src/server.ts:

app.use(cors({
  origin: process.env.CLIENT_URL,
  credentials: true,
}));

Example:
CLIENT_URL=http://localhost:3000

2. Database & Storage

`DATABASE_URL`

Location: backend/.env
Description: Target PostgreSQL database instance. Required for running migrations via Drizzle ORM and managing client queries through pg.Pool.
Format: postgresql://[user]:[password]@[host]:[port]/[database]?sslmode=[mode]

Example:

DATABASE_URL=postgresql://postgres:postgres@localhost:5432/gobetter_db

`REDIS_URL`

Location: backend/.env
Description: Redis instance utilized for BullMQ task distribution, queueing pull request webhooks, managing user sessions, and coordinating async worker jobs.
Example:
REDIS_URL=redis://localhost:6379

3. AI Engine & Provider Routing

`BASE_MODEL`

Location: backend/.env
Description: Default model slug invoked when a review job does not supply an explicit model preference.
Example:
BASE_MODEL=openai/gpt-4o

`AI_API_KEY` & `AI_BASE_URL`

Location: backend/.env
Description: Supplies authentication and custom base URL for the backend’s AI service (backend/src/service/ai.service.ts).

Example:

AI_API_KEY=sk-proj-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
AI_BASE_URL=https://api.openai.com/v1

`OPEN_AI_INTERFACE`

Location: backend/.env
Description: Determines interface method on OpenAI SDK (chat by default).

4. Email Service & Delivery

`RESEND_API_KEY`

Location: backend/.env
Description: Authenticates with Resend API (backend/src/lib/resendEmail.ts) to dispatch transactional authentication emails (email verification OTPs, password reset links).
Example:
RESEND_API_KEY=re_123456789_abcdefg

5. Platform Branding & Email Theming

Configured in backend/.env or defaults in backend/src/config/config.ts:

Variable	Default	Purpose
`BRAND_NAME`	`Go Better`	Visible brand name in notification headings and emails
`BRAND_URL`	`https://gobetter.dev`	Landing page URL linked in footers
`BRAND_TAGLINE`	`Autonomous AI Code Reviews`	Subtitle displayed in email headers
`FROM_EMAIL`	`noreply@mail.gobetter.dev`	Envelope sender address
`FROM_SENDER`	`Go Better <noreply@mail.gobetter.dev>`	Friendly from-name and address
`EMAIL_THEME`	`dark`	Email template theme (`dark` or `light`)
`BRAND_LOGO_URL`	`https://gobetter.dev/gobetter-logo.png`	Public URL for email header badge

6. In-Code Platform Pricing & Quotas

Located in backend/src/config/config.ts:

// Amount user can spend on the platform before they need to enable BYOK
export const perUserSpendLimit = 0.30;

export const goBetterFreeModels = {
    'alibaba/qwen3.7-flash': {
        inputCost: 0.03,
        outputCost: 0.13
    },
    'deepseek/deepseek-v4-flash-0731': {
        inputCost: 0.05,
        outPutCost: 0.10
    },
    'nvidia/nemotron-3.5-lightning': {
        inputCost: 0.05,
        outPutCost: 0.15
    },
    'zai/glm-4.7-flashx': {
        inputCost: 0.06,
        outputCost: 0.40
    },
    'openai/gpt-oss-20b': {
        inputCost: 0.07,
        outputCost: 0.30
    },
};

export const goBetterBaseUrl = 'https://api.inceptionlabs.ai/v1/chat/completions';

Server Environment Template (`backend/.env.example`)

# Copy backend/src/.env.example to backend/src/.env, then replace placeholders.
PORT="YOUR_VALUE_HERE"
BASE_MODEL="YOUR_VALUE_HERE"
AI_BASE_URL="YOUR_VALUE_HERE"
AI_API_KEY="YOUR_VALUE_HERE"
OPEN_AI_INTERFACE="YOUR_VALUE_HERE"
GITHUB_ACESSES_TOKEN="YOUR_VALUE_HERE"
REDIS_URL="YOUR_VALUE_HERE"
DATABASE_URL="YOUR_VALUE_HERE"
API_ENCRYPTION_KEY="YOUR_VALUE_HERE"
CLIENT_URL="YOUR_VALUE_HERE"
API_BASE_URL="YOUR_VALUE_HERE"
BETTER_AUTH_URL="YOUR_VALUE_HERE"
RESEND_API_KEY="YOUR_VALUE_HERE"
GITHUB_APP_CLIENT_ID="YOUR_VALUE_HERE"
GITHUB_APP_CLIENT_SECRET="YOUR_VALUE_HERE"
GITHUB_APP_SLUG="YOUR_VALUE_HERE"

Get Started

Configuration

Architecture & Workflows

AI Engine & Harness

Engineering Standards

API Reference

Server Configuration

Configuration Overview Table

Detailed Configuration Breakdown

Where to Get Each Backend Value

Generate an Encryption Key

Backend Secrets and Rotation

1. Networking & CORS

`PORT`

`CLIENT_URL`

2. Database & Storage

`DATABASE_URL`

`REDIS_URL`

3. AI Engine & Provider Routing

`BASE_MODEL`

`AI_API_KEY` & `AI_BASE_URL`

`OPEN_AI_INTERFACE`

4. Email Service & Delivery

`RESEND_API_KEY`

5. Platform Branding & Email Theming

6. In-Code Platform Pricing & Quotas

Server Environment Template (`backend/.env.example`)

​Configuration Overview Table

​Detailed Configuration Breakdown

​Where to Get Each Backend Value

​Generate an Encryption Key

​Backend Secrets and Rotation

​1. Networking & CORS

​PORT

​CLIENT_URL

​2. Database & Storage

​DATABASE_URL

​REDIS_URL

​3. AI Engine & Provider Routing

​BASE_MODEL

​AI_API_KEY & AI_BASE_URL

​OPEN_AI_INTERFACE

​4. Email Service & Delivery

​RESEND_API_KEY

​5. Platform Branding & Email Theming

​6. In-Code Platform Pricing & Quotas

​Server Environment Template (backend/.env.example)

Configuration Overview Table

Detailed Configuration Breakdown

Where to Get Each Backend Value

Generate an Encryption Key

Backend Secrets and Rotation

1. Networking & CORS

`PORT`

`CLIENT_URL`

2. Database & Storage

`DATABASE_URL`

`REDIS_URL`

3. AI Engine & Provider Routing

`BASE_MODEL`

`AI_API_KEY` & `AI_BASE_URL`

`OPEN_AI_INTERFACE`

4. Email Service & Delivery

`RESEND_API_KEY`

5. Platform Branding & Email Theming

6. In-Code Platform Pricing & Quotas

Server Environment Template (`backend/.env.example`)