# Configuration
URL: https://usememos.com/docs/configuration

Configure Memos around how your instance runs, where its data lives, and how people sign in. These pages explain startup options, deployment-managed settings, database and attachment storage, and access controls.

<Cards>
  <Card title="Environment Variables" href="/docs/configuration/environment-variables" icon="Terminal">
    Set the listen address, port, data directory, database connection, and canonical instance URL.
  </Card>

  <Card title="Deployment-Managed Configuration" href="/docs/configuration/deployment-configuration" icon="Settings">
    Load selected instance settings and identity providers from mounted JSON files at startup.
  </Card>

  <Card title="Database" href="/docs/configuration/database" icon="Database">
    Configure SQLite, MySQL, or PostgreSQL and understand the operational tradeoffs.
  </Card>

  <Card title="Storage" href="/docs/configuration/storage" icon="HardDrive">
    Choose where attachments live and manage named storage configurations for new and existing files.
  </Card>

  <Card title="Authentication" href="/docs/configuration/authentication" icon="Key">
    Configure password sign-in, SSO providers, and personal access tokens.
  </Card>

  <Card title="Security" href="/docs/configuration/security" icon="Shield">
    Review HTTPS, credentials, sharing, and recovery as part of operating your instance.
  </Card>
</Cards>

## Choose the question you need to answer [#choose-the-question-you-need-to-answer]

| If you want to know…                                               | Start with…                                                                      |
| ------------------------------------------------------------------ | -------------------------------------------------------------------------------- |
| How do I change the port, data path, or external URL?              | [Environment Variables](/docs/configuration/environment-variables)               |
| How do I keep settings under deployment or secret-manager control? | [Deployment-Managed Configuration](/docs/configuration/deployment-configuration) |
| Which database fits my deployment?                                 | [Database](/docs/configuration/database)                                         |
| Where should uploads be stored?                                    | [Storage](/docs/configuration/storage)                                           |
| How do I set up SSO or authenticate an integration?                | [Authentication](/docs/configuration/authentication)                             |
| What should I review before exposing the instance?                 | [Security](/docs/configuration/security)                                         |

## Configuration layers [#configuration-layers]

Runtime flags and `MEMOS_*` environment variables control server startup. Instance settings manage policies and services through the UI or API. When a supported setting is supplied by a deployment-managed file, that file is authoritative for the server process; changes to it require a restart.

In Memos 0.31, the `ACCESS` instance setting selects public or private access independently of `MEMOS_INSTANCE_URL`. Set the URL to the canonical external HTTP(S) address, including for private instances behind a proxy. Manage access in instance settings or a [deployment-managed access file](/docs/configuration/deployment-configuration#access-policy).

For the installation itself, start with [Deploy](/docs/deploy). Once Memos is running, use [Admin](/docs/admin) for ongoing instance and account management, and [Reverse Proxy](/docs/deploy/reverse-proxy) for HTTPS and forwarded headers.