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## 5.19.0

**`(feat):`** Add automatic idempotency-key generation, driven by the centralized
`idempotencyKeyGeneration` config in the IR. When enabled, the generated SDK attaches a
UUIDv4 idempotency-key header to requests whose HTTP method is listed in the IR. A
caller-supplied key still takes precedence.

## 5.18.4

**`(fix):`** Fix smart-casing snake\_case names dropping the word boundary after a number.
Sub-client accessors and methods like `ConversationsV2Configuration` now generate
`conversations_v2_configuration` instead of `conversations_v2configuration`.

## 5.18.3

**`(fix):`** Expose basic auth credentials (e.g. `account_sid` / `auth_token`) on the top-level
client when the API also configures OAuth (`auth: any`). Previously the root client
constructor only accepted OAuth client credentials or a bearer token, even though the
underlying client wrapper supported basic auth. The credentials are now optional
constructor parameters that are forwarded to the client wrapper, and the client can be
instantiated with basic auth alone without raising an error.