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/src/.env when that file exists.

The production backend container runs pending Drizzle migrations before starting the API. Set DATABASE_URL in the container environment before startup. Keep migration execution in the container’s startup command rather than the image build so the image can be built without database access.

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_OAUTH_*`, `GITHUB_APP_SLUG`, `GITHUB_WEBHOOK_VERIFICATION_SECRET`	`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_OAUTH_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_OAUTH_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_OAUTH_SCOPE`	Yes for GitHub OAuth Apps	Set to `user:email`. The login flow uses it to retrieve a private primary email address.
`GITHUB_APP_SLUG`	Yes for GitHub App links	Copy the slug from the GitHub App installation URL or app settings.
`GITHUB_WEBHOOK_VERIFICATION_SECRET`	Yes for GitHub webhooks	Create a strong random secret in the GitHub webhook settings and configure the same value in the backend environment. GitHub uses it to generate the `X-Hub-Signature-256` header.

`GITHUB_WEBHOOK_VERIFICATION_SECRET`

This secret authenticates incoming POST /webhook requests. The backend verifies GitHub’s HMAC-SHA256 signature against the raw request body before checking the event type or writing to PostgreSQL and Redis. Configure the same secret in both places:

In the GitHub repository or GitHub App webhook settings, enter it in the Secret field.
In backend/src/.env or the production backend environment, set GITHUB_WEBHOOK_VERIFICATION_SECRET to the same value.

Do not add the secret to the frontend, commit it to source control, or include it in logs. The /webhook endpoint does not require a user session because GitHub authenticates it with this signature.

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_OAUTH_CLIENT_ID="YOUR_VALUE_HERE"
GITHUB_OAUTH_CLIENT_SECRET="YOUR_VALUE_HERE"
GITHUB_OAUTH_SCOPE="user:email"
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

`GITHUB_WEBHOOK_VERIFICATION_SECRET`

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

​GITHUB_WEBHOOK_VERIFICATION_SECRET

​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

`GITHUB_WEBHOOK_VERIFICATION_SECRET`

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`)