C13. Set an Overall Timeout

The three timeouts from C12. Set timeouts all apply to a single send or recv call. To cap the total time a request can take, use set_max_timeout().

Basic usage

httplib::Client cli("http://localhost:8080");

cli.set_max_timeout(5000); // 5 seconds (in milliseconds)

auto res = cli.Get("/slow-endpoint");

httplib::Client cli("http://localhost:8080");

cli.set_max_timeout(5000); // 5 seconds (in milliseconds)

auto res = cli.Get("/slow-endpoint");

The value is in milliseconds. Connection, send, and receive together — the whole request is aborted if it exceeds the limit.

Use std::chrono

There's also an overload that takes a std::chrono duration.

using namespace std::chrono_literals;
cli.set_max_timeout(5s);

using namespace std::chrono_literals;
cli.set_max_timeout(5s);

When to use which

set_read_timeout fires when no data arrives for a while. If data keeps trickling in bit by bit, it will never fire. An endpoint that sends one byte per second can make set_read_timeout useless no matter how short you set it.

set_max_timeout caps elapsed time, so it handles those cases cleanly. It's great for calls to external APIs or anywhere you don't want users waiting forever.

cli.set_connection_timeout(3s);
cli.set_read_timeout(10s);
cli.set_max_timeout(30s); // abort if the whole request takes over 30s

cli.set_connection_timeout(3s);
cli.set_read_timeout(10s);
cli.set_max_timeout(30s); // abort if the whole request takes over 30s

Note: set_max_timeout() works alongside the regular timeouts. Short stalls get caught by set_read_timeout; long-running requests get capped by set_max_timeout. Use both for a safety net.