pub fn main(world: World) -> Void raises {
    let maybe_request: Maybe<String> = std.args.get(1)
    if !maybe_request.has {
        check world.err.write("usage: pass HTTP request envelope\n")
        return
    }
    let net: Net = std.net.host()
    let client: HttpClient = std.http.client(net)
    var response: [512]u8 = [0_u8; 512]
    let result: HttpResult = std.http.fetch(client, std.mem.span(maybe_request.value), response, std.time.ms(5000))
    if !std.http.resultOk(result) {
        check world.err.write("http json fetch failed\n")
        return
    }
    let bytes: Maybe<Span<u8>> = std.http.responseBody(response, result)
    var arena_buf: [16]u8 = [0_u8; 16]
    var arena: FixedBufAlloc = std.mem.fixedBufAlloc(arena_buf)
    var parsed: Maybe<JsonDoc> = null
    if bytes.has {
        parsed = std.json.parseBytes(arena, bytes.value)
    }
    if bytes.has && parsed.has && std.json.validateBytes(bytes.value) && std.json.streamTokensBytes(bytes.value) == 3 {
        check world.out.write("http json ok\n")
        return
    }
    check world.err.write("http json parse failed\n")
}