405 Not Allowed Here

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

"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." 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. The clerk didn't even look at the letter

"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. That building accepts the POST method

"I don't understand," Eli said. "Is the library closed? Is the address wrong?"

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