5. Request Body¶

Body sources are mutually exclusive. You can use only one of body, bodyStream, form, or multipart — specifying two or more fails with an exception.

Typed JSON¶

client.post("/games").body(CreateGameReq("ranked-match-0611")).await<CreateGameRes>()

body(value) serializes the value with Jackson and sets content-type: application/json. A data class is serialized as-is.

Raw Body¶

client.post("/raw").body("plain text payload", "text/plain").awaitRaw()

body(content, contentType) (2 arguments) sets a raw body and an explicit content-type.

Form-Urlencoded¶

client.post("/login").form("user", "aria").form("password", "secret value").awaitRaw()
// content-type: application/x-www-form-urlencoded, percent-encoding applied

Multipart/Form-Data¶

client.post("/upload")
    .multipart("title", "patch notes")
    .multipartFile("file", "notes.txt", fileContent, "text/plain")
    .awaitRaw()

Streaming Upload¶

bodyStream(provider, contentType) sends the body chunk by chunk with chunked transfer-encoding. It ends when the provider returns null. A streaming request can't be rewound, so it's excluded from automatic retry.

val chunks = ArrayDeque(listOf("a".toByteArray(), "b".toByteArray()))
client.post("/upload-stream")
    .bodyStream({ if (chunks.isEmpty()) null else chunks.poll() }, "application/octet-stream")
    .awaitRaw()

Next: Handling Responses →