EdgeDB supports GET and POST methods for handling GraphQL over HTTP protocol. Both GET and POST methods use the following fields:

  • query - contains the GraphQL query string

  • operationName - contains the name of the operation that must be executed. It is required if the GraphQL query contains several named operations, otherwise it is optional.

  • variables - contains a JSON object where keys and values correspond to the variable names and values. It is required if the GraphQL query has variables, otherwise it is optional.

The protocol implementations conform to the official GraphQL HTTP protocol.

The protocol supports HTTP Keep-Alive.

The HTTP GET request passes the fields as query parameters: query, operationName, and variables.

The POST request should use application/json content type and submit the following JSON-encoded form with the necessary fields:

  "query": "...",
  "operationName": "...",
  "variables": { "varName": "varValue", ... }

The response format is the same for both methods. The body of the response is JSON of the following form:

  "data": { ... },
  "errors": [
    { "message": "Error message"}, ...

Note that the errors field will only be present if some errors actually occurred.

Caution is advised when reading decimal or bigint values (mapped onto Decimal and Bigint GraphQL custom scalar types) using HTTP protocol because the results are provides in JSON format. The JSON specification does not have a limit on significant digits, so a decimal or a bigint number can be losslessly represented in JSON. However, JSON decoders in many languages will read all such numbers as some kind of of 32- or 64-bit number type, which may result in errors or precision loss. If such loss is unacceptable, then consider creating a computed property which casts the value into str and decoding it on the client side into a more appropriate type.