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[@salesforce/b2c-tooling-sdk](../../modules.md) / [clients](../index.md) / MRT\_READ\_ONLY\_HEADER

# Variable: MRT\_READ\_ONLY\_HEADER

> `const` **MRT\_READ\_ONLY\_HEADER**: `"X-MRT-Read-Only"` = `'X-MRT-Read-Only'`

Defined in: [packages/b2c-tooling-sdk/src/clients/mrt.ts:115](https://github.com/SalesforceCommerceCloud/b2c-developer-tooling/blob/1cc5681b8c76554833dc7a40097f33641882a372/packages/b2c-tooling-sdk/src/clients/mrt.ts#L115)

Header MRT sets on every response while in read-only (maintenance) mode.