Configure the Kotlin Client

The trailing-lambda constructor configures the client through the same validated options as Java — a null property keeps the default:

RepostClient {
    apiKey = System.getenv("REPOST_SEND_API_KEY")
    operationTimeout = Duration.ofSeconds(30)
    maxAttempts = 4
    maxInFlightOperations = 128
}

Credential and endpoint precedence

Credential precedence, highest first: an apiKeyProvider → a fixed apiKey → the REPOST_SEND_API_KEY environment variable → the REPOST_TOKEN environment variable. With none set, the first send fails with a CONFIGURATION error and never touches the network. Base URI: an explicit baseUri → REPOST_API_URL → the default https://api.repost.sh. Plain http:// is accepted only for loopback hosts.

Defaults

The defaults match the Java SDK: 120s operation deadline, 30s per attempt, 4 attempts, 256 in-flight operations, a 64 MiB byte budget. The config object never prints your credential.

Proxy, TLS, and mTLS

Build HttpTransportOptions and set it via the httpTransportOptions property: an explicit proxy with an optional credentials provider, a borrowed SSLContext for a custom truststore or mutual TLS, and an allowlisted TLS protocol (TLS 1.2/1.3) and cipher list. HTTP redirects are disabled.

Continue

Reliability

Idempotency, the five delivery states, and coroutine cancellation.

Observability

Diagnostics, lifecycle observers, Micrometer, and OpenTelemetry.

Frameworks

Spring Boot properties, Jakarta CDI config, and container lifecycle.

Send

Schema

Publishing

Delivery

Customer experience

TypeScript

Go

C#

Python

Java

Kotlin

Configure the Kotlin Client

Credential and endpoint precedence

Defaults

Proxy, TLS, and mTLS

Continue

Reliability

Observability

Frameworks

​Credential and endpoint precedence

​Defaults

​Proxy, TLS, and mTLS

​Continue

Reliability

Observability

Frameworks

Credential and endpoint precedence

Defaults

Proxy, TLS, and mTLS

Continue