405 Not Allowed -

"I’d like to this letter into the library's collection," Eli said, sliding a sealed envelope toward the slot.

Eli, a young traveler, stood before the heavy oak doors of the . He had a simple task: he wanted to leave a letter for a friend. He walked up to the reception desk, where a clerk sat behind a glass partition.

The clerk didn't even look at the letter. Instead, he stamped a red mark on a form and slid it back. It read: 405 Not Allowed

Eli sighed, realizing his mistake. He had the right address, but he was trying to use an "enter" key on a door that only had a handle to "exit." He tucked his letter away and set off for the correct endpoint.

"If you want to leave something," the clerk explained, "you need to go to the . That building accepts the POST method. Here, we only let people look." "I’d like to this letter into the library's

For a quick technical breakdown of why this error happens in the real world, check out this summary:

The clerk pointed to a small plaque on the wall—the . It listed the only "verbs" the building accepted: GET, HEAD, OPTIONS . He walked up to the reception desk, where

"The library is right here," the clerk droned, pointing to the shelves of books behind him. "You’ve got the right place. But this is an . It is a read-only establishment. You can GET a book, you can HEAD a title, but you cannot POST a letter here. We simply don't allow that method of interaction." "But I have to leave this letter!" Eli insisted.