Darkmown 2.7 # What the API actually said A real API explains why it refused. `_error` used to read `Error: HTTP 422` no matter what came back. It is now the body's own `error` or `message` string, and the whole parsed body lands in `_error_body`, so a page can render per-field errors without a line of its own JavaScript.

## A refusal, rendered `/api/echo` only accepts POST, so a plain `:fetch` gets a `405` whose JSON body carries an `error` string. :fetch probe from "/api/echo/" :if probe_loading Asking the endpoint… :endif :if probe_error The endpoint said: **{ probe_error }** :endif :if probe_error_body And the whole body is available too: `ok` came back as { probe_error_body.ok }. :endif

## Field-level errors `/api/upload` answers a fileless POST with a `422` whose body carries both a sentence and a per-field map: ```json { "error": "Pick a file first.", "fields": { "photo": "No file was attached." } } ``` A page renders each half where it belongs: ```wd-fragment :if signup_error { signup_error } :endif { signup_error_body.fields.email } ``` The [upload demo](/upload/) has this wired up end to end.

## The rules - `_error` prefers the body's `error` field, then its `message` field, and falls back to `HTTP ` when the body has neither or is not JSON at all. - `_error_body` is the parsed JSON body, or `null` when the response was not JSON. - Both keys are auto-declared by `:fetch` and by a round-trip `:form`, and both are cleared on the next success. Read the docs on fetching data