fix: allow POST requests without body / content-type header (#6881)

This is not possible for most routes as request will fail schema validation

packages/api/src/utils/server/handler.ts

@@ -65,15 +65,22 @@ export function createFastifyHandler<E extends Endpoint>(
  returnBytes: responseWireFormat === WireFormat.ssz,
  });
  } else {
+ let requestWireFormat: WireFormat;
  const contentType = req.headers[HttpHeader.ContentType];
- if (contentType === undefined) {
- throw new ApiError(400, "Content-Type header is required");
+ if (contentType === undefined && req.body === undefined) {
+ // Default to json parser if body is omitted. This is not possible for most
+ // routes as request will fail schema validation before this handler is called
+ requestWireFormat = WireFormat.json;
+ } else {
+ if (contentType === undefined) {
+ throw new ApiError(400, "Content-Type header is required");
+ }
+ const requestMediaType = parseContentTypeHeader(contentType);
+ if (requestMediaType === null) {
+ throw new ApiError(415, `Unsupported media type: ${contentType.split(";", 1)[0]}`);
+ }
+ requestWireFormat = getWireFormat(requestMediaType);
  }
- const requestMediaType = parseContentTypeHeader(contentType);
- if (requestMediaType === null) {
- throw new ApiError(415, `Unsupported media type: ${contentType.split(";", 1)[0]}`);
- }
- const requestWireFormat = getWireFormat(requestMediaType);
 
  const {onlySupport} = definition.req as RequestWithBodyCodec<E>;
  if (onlySupport !== undefined && onlySupport !== requestWireFormat) {