Custom User Data

Stack Auth allows storing additional user information through three types of metadata fields:

1. clientMetadata: Readable and writable from a client.
2. serverMetadata: Readable and writable only from a server.
3. clientReadOnlyMetadata: Readable from a client, writable only from a server.

Client metadata

You can use the clientMetadata field to store non-sensitive information that both the client and server can read and write.

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await user.update({
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  clientMetadata: {
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    mailingAddress: "123 Main St",
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  },
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});
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// On the client:
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const user = useUser();
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console.log(user.clientMetadata);

Server-side metadata

For sensitive information, use the serverMetadata field. This ensures the data is only accessible and modifiable by the server.

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const user = await stackServerApp.getUser();
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await user.update({
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  serverMetadata: {
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    secretInfo: "This is a secret",
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  },
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});
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// To read:
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const user = await stackServerApp.getUser();
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console.log(user.serverMetadata);

Client read-only metadata

Use clientReadOnlyMetadata for data that clients need to read but never modify, such as subscription status.

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// On the server:
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const user = await stackServerApp.getUser();
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await user.update({
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  clientReadOnlyMetadata: {
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    subscriptionPlan: "premium",
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  },
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});
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// On the client:
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const user = useUser();
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console.log(user.clientReadOnlyMetadata);