Serializes PostgREST's error envelope to its exact wire bytes.

Two properties are pinned by the conformance suite and neither survives a plain map encode, so every error body goes through here.

Key emission order is ALPHABETICAL

errorPayload constructs the object as [code, message, details, hint] (Error.hs#L69-L74) but emits it with JSON.encode over an aeson KeyMap (Error.hs#L66). PostgREST pins aeson >= 2.0.3 && < 2.3 and overrides neither postgrest.cabal nor cabal.project for aeson's ordered-keymap flag, whose default is True — so KeyMap is a Data.Map.Strict and the encoder walks its keys in ascending order. The bytes on the wire are therefore {"code":…,"details":…,"hint":…,"message":…}, compact, and NOT in construction order.

Bier's default encoder (Elixir's stdlib JSON, via Bier.json_library/0) preserves neither: a map literal iterates in atom-creation order. The object is assembled here explicitly instead, one Bier.json_library/0-encoded value at a time.

client-error-verbosity

toJsonPgrstError (Error.hs#L69-L78) selects the members: :verbose (the default) emits code, message, details and hint; :minimal emits only code and message — details and hint are OMITTED entirely, not set to null. The verbosity is applied once, to every error the request pipeline produces (App.hs#L154), so it governs database errors as much as the PGRSTxxx ones, and Response.hs passes the same setting to the 416 body it builds inline while assembling a normal read response.