echo

echo

Rewrites the response: body replaces the upstream body, before_body / after_body are concatenated around it, and headers are set on the response. It is a response-phase node — place it after upstream (between upstream and client) so it sees the upstream response. It is intended as a demo/debugging utility.

Configuration

At least one of body / before_body / after_body is required.

Key	Type	Default	Description
body	string	—	Replaces the upstream response body.
before_body	string	—	Prepended to the body (after any body replacement).
after_body	string	—	Appended to the body.
headers	map or array	{}	Response headers to set. Accepts the map form {name: value} and the array form [{name, value}] (the shape the UI editor saves; blank-name rows are skipped). Values must be scalars (strings, numbers, bools — stringified); names are lowercased. Existing values for the same header are replaced, not appended (like ngx.header).

type: echo
config:
  before_body: "before the body modification "
  after_body: " after the body modification"
  headers:
    x-served-by: featherbit

Malformed shapes are rejected at config load: non-string body keys, a non-map headers, or non-scalar header values all fail with a descriptive error.

Behavior

This plugin never fails at execution time — it always exits through the success port, and the error port is never taken.

On each response, in order:

1. With body, the upstream body is discarded and replaced. Without it, the upstream body is kept — and if it is compressed (content-encoding: gzip, deflate, or br), it is decoded first so before_body/after_body concatenate onto text rather than onto a compressed stream. An unsupported encoding or corrupt stream falls back to the raw bytes.
2. before_body and after_body are concatenated around the result.
3. Per the body-mutation convention, content-length is removed (the server recomputes it from the final body) and content-encoding is removed (the body is left decoded).
4. headers are set on context.response.headers, replacing any existing values.