POST
Create or reuse a human direct conversation

Authorizations

Authorization
string
header
required

Better Auth user-session bearer used by the Relay app; never an Agent Token.

Headers

Idempotency-Key
string
required

Deriving it from the triggering event_id makes a retry safe.

Required string length: 8 - 255

Body

application/json
user_id
string
required

Verified Relay user to message.

Pattern: ^usr_

Response

Existing conversation for this user pair.

conversation
object
required