Sync open source content 🐝 (from 3f48a621faa48868bd80438b763cb07f71a84bef)

Author: beezythebot

docs/sdks/customize/data-model/enums.mdx

@@ -67,6 +67,44 @@ schema:
     - COMPLETE
 ```
 
+## Preserve custom enum names in TypeScript
+
+When `x-speakeasy-enums` provides custom names, the TypeScript generator applies PascalCase transformation by default. This can mangle names where casing carries meaning. For example, `X86_64` becomes `X8664` because the transformation strips underscores and collapses digits.
+
+To preserve custom enum names exactly as written, enable the [`fixEnumNameSanitization`](/docs/speakeasy-reference/generation/ts-config#error-and-response-handling) option in `gen.yaml`:
+
+```yaml
+typescript:
+  fixEnumNameSanitization: true
+```
+
+With this option enabled, custom names provided via `x-speakeasy-enums` are kept as-is, with only illegal character sanitization applied. No PascalCase or other casing transformations are performed.
+
+For example, given the following OpenAPI schema and `gen.yaml` configuration:
+
+```yaml
+# gen.yaml
+typescript:
+  fixEnumNameSanitization: true
+```
+
+```yaml
+# OpenAPI spec
+ImageArchitecture:
+  enum: ["x86_64", "arm64"]
+  type: string
+  x-speakeasy-enums:
+    x86_64: X86_64
+```
+
+The generated enum member is `X86_64` instead of `X8664`.
+
+<Callout title="Note" type="info">
+  The `fixEnumNameSanitization` option is currently available for TypeScript only (including `mcp-typescript`). It applies exclusively to enums with `x-speakeasy-enums` overrides — enums without custom names are unaffected.
+</Callout>
+
+Because this option skips all casing transformations for custom names, names are used exactly as provided. For example, a custom name like `under_review` remains `under_review` in the generated output rather than being converted to `UnderReview`.
+
 ## Enum class naming
 
 Use the `x-speakeasy-name-override` attribute to customize enum class names:

docs/speakeasy-reference/generation/ts-config.mdx

@@ -278,6 +278,7 @@ typescript:
   clientServerStatusCodesAsErrors: true
   responseFormat: "flat"
   enumFormat: "union"
+  fixEnumNameSanitization: false
   defaultErrorName: "SDKError"
   baseErrorName: "HTTPError"
   acceptHeaderEnum: false
@@ -287,6 +288,7 @@ typescript:
   data={[
     { property: "[responseFormat](/docs/sdks/customize/responses/responses)", description: "Defines how responses are structured. Options: `envelope`, `envelope-http`, or `flat`.", type: "string", default: "flat" },
     { property: "enumFormat", description: "Determines how enums are generated. Options: `enum` (TypeScript enums) or `union` (union types).", type: "string", default: "union" },
+    { property: "[fixEnumNameSanitization](/docs/customize-sdks/enums#preserve-custom-enum-names-in-typescript)", description: "When `true`, custom enum names provided via `x-speakeasy-enums` are preserved exactly as written, with only illegal character sanitization applied. No PascalCase or other casing transformations are performed. Only affects enums with `x-speakeasy-enums` overrides.", type: "boolean", default: "false" },
     { property: "clientServerStatusCodesAsErrors", description: "Treats `4XX` and `5XX` status codes as errors. Set to `false` to treat them as normal responses.", type: "boolean", default: "true" },
     { property: "defaultErrorName", description: "The name of the fallback error class if no more specific error class is matched. Must start with a capital letter and contain only letters and numbers.", type: "string", default: "SDKError" },
     { property: "baseErrorName", description: "The name of the base error class used for HTTP error responses. Must start with a capital letter and contain only letters and numbers.", type: "string", default: "HTTPError" },