> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/TinsFox/ai-review/llms.txt
> Use this file to discover all available pages before exploring further.

# Environment variables

> Complete reference for all environment variables used by AI Review.

Copy `.env.example` from the repository root to `.env` and fill in the required
values before starting the server.

## Required

<ParamField path="DATABASE_URL" type="string" required>
  PostgreSQL connection string.

  Format: `postgresql://username:password@host:port/database`

  Example: `postgresql://ai_review:ai_review@localhost:15432/ai_review`
</ParamField>

<ParamField path="BETTER_AUTH_SECRET" type="string" required>
  Secret key used by Better Auth for session signing. Must be at least 32
  characters long.
</ParamField>

## Server

<ParamField path="NODE_ENV" type="string" default="development">
  Runtime environment. Accepted values: `development`, `production`, `test`.
</ParamField>

<ParamField path="PORT" type="number" default="3000">
  Port the API server listens on.
</ParamField>

<ParamField path="HOSTNAME" type="string" default="localhost">
  Hostname or IP address the server binds to.
</ParamField>

<ParamField path="APP_URL" type="string (URL)">
  Public URL of the application. Used as the canonical base URL and as the
  default value for `APP_URLs` and `BETTER_AUTH_URL` when those are not set
  explicitly.
</ParamField>

<ParamField path="APP_URLs" type="string" default="http://localhost:3000">
  Comma-separated list of allowed application URLs used for CORS and redirect
  validation. Defaults to `APP_URL` when `APP_URL` is set.
</ParamField>

<ParamField path="API_URL" type="string (URL)">
  Backend API URL used by the web development proxy. Defaults to `APP_URL`.
</ParamField>

<ParamField path="WEBHOOK_BASE_URL" type="string (URL)">
  Base URL for outbound webhook callbacks (e.g., GitLab/GitHub event
  verification replies).
</ParamField>

<ParamField path="BETTER_AUTH_URL" type="string (URL)">
  Override the URL Better Auth uses for its endpoints. Defaults to the first
  entry in the resolved `APP_URLs` list.
</ParamField>

<ParamField path="SYSTEM_NAME" type="string">
  Display name for the platform. Appears in logs, emails, and notification
  messages. Example: `AI Review Platform`.
</ParamField>

<ParamField path="CORS_ORIGIN" type="string">
  Explicit CORS origin override. If not set, CORS is derived from `APP_URLs`.
</ParamField>

## Queue

<ParamField path="REDIS_URL" type="string" required>
  Redis connection URL required by BullMQ for persistent task queues. The server throws an error on startup if this is not set.

  Example: `redis://localhost:16379`
</ParamField>

## AI provider

<ParamField path="VOLCENGINE_API_KEY" type="string">
  API key for the Volcengine (Doubao) AI provider. Required for AI-powered code
  reviews — Volcengine is the only currently active provider.
</ParamField>

<ParamField path="VOLCENGINE_ENDPOINT" type="string">
  Inference endpoint URL for your Volcengine deployment. Required alongside
  `VOLCENGINE_API_KEY`.
</ParamField>

<ParamField path="AI_REVIEW_CONCURRENCY" type="number" default="3">
  Maximum number of AI review jobs executed concurrently by the server.
</ParamField>

<ParamField path="REVIEW_TIMEOUT_MINUTES" type="number" default="30">
  Timeout in minutes for a single review job before it is marked as failed.
</ParamField>

<ParamField path="OPENAI_API_KEY" type="string">
  OpenAI API key. Parsed by the schema but not active in the current release.
</ParamField>

<ParamField path="ANTHROPIC_API_KEY" type="string">
  Anthropic Claude API key. Parsed by the schema but not active in the current
  release.
</ParamField>

<ParamField path="AZURE_OPENAI_API_KEY" type="string">
  Azure OpenAI API key. Parsed by the schema but not active in the current
  release.
</ParamField>

<ParamField path="AZURE_OPENAI_ENDPOINT" type="string">
  Azure OpenAI endpoint URL. Parsed by the schema but not active in the current
  release.
</ParamField>

<ParamField path="VERCEL_API_KEY" type="string">
  Vercel AI API key. Parsed by the schema but not active in the current release.
</ParamField>

<ParamField path="MOONSHOT_API_KEY" type="string">
  Moonshot API key. Parsed by the schema but not active in the current release.
</ParamField>

## Runner

<ParamField path="RUNNER_HEARTBEAT_TIMEOUT_MS" type="number" default="60000">
  Milliseconds after which a Runner that has not sent a heartbeat is considered
  offline. Default is 60 000 ms (60 seconds).
</ParamField>

## Logging

<ParamField path="LOG_DIR" type="string">
  Directory path where log files are written. Example: `./logs`.
</ParamField>

<ParamField path="LOG_LEVEL" type="string">
  Minimum log level to emit. Accepted values: `error`, `warn`, `info`, `debug`.
</ParamField>

<ParamField path="LOG_RETENTION_DAYS" type="number">
  Number of days to retain log files before automatic cleanup.
</ParamField>

## Backup

<ParamField path="BACKUP_DIR" type="string">
  Directory path for database backup files. Example: `./backups`.
</ParamField>

<ParamField path="AUTO_BACKUP_ENABLED" type="boolean" default="false">
  When `true`, the server runs an automatic database backup daily at 02:00.
</ParamField>

<ParamField path="BACKUP_RETENTION_DAYS" type="number">
  Number of days to keep backup files before they are deleted.
</ParamField>

## Metrics

<ParamField path="METRICS_RETENTION_DAYS" type="number">
  Number of days to retain metrics data. Example: `90`.
</ParamField>

## System

<ParamField path="RESET_DB_KEY" type="string">
  Secret key required to call `POST /api/system/reset`. Keep this value private;
  the endpoint deletes all data.
</ParamField>

<ParamField path="ROOT_EMAIL" type="string">
  Email address for the initial root user created on first startup. Has no
  effect after the root user already exists.
</ParamField>

<ParamField path="ROOT_PASSWORD" type="string">
  Password for the initial root user created on first startup.
</ParamField>

## OAuth (optional)

<ParamField path="GITHUB_CLIENT_ID" type="string">
  GitHub OAuth application client ID. Reserved for future OAuth login support.
</ParamField>

<ParamField path="GITHUB_CLIENT_SECRET" type="string">
  GitHub OAuth application client secret. Reserved for future OAuth login
  support.
</ParamField>

<ParamField path="GITLAB_CLIENT_ID" type="string">
  GitLab OAuth application client ID. Reserved for future OAuth login support.
</ParamField>

<ParamField path="GITLAB_CLIENT_SECRET" type="string">
  GitLab OAuth application client secret. Reserved for future OAuth login
  support.
</ParamField>

<ParamField path="GITLAB_CLIENT_ISSUER" type="string">
  Issuer URL for the GitLab instance used for OAuth. Example:
  `https://gitlab.example.com`.
</ParamField>