Shopify GraphQL Checkout Create Mutation - graphql

Question

I cannot create a checkout with Shopify's Graphql API
I am literally copying the example from this page in Shopify's Checkout Guide and pasting it into Shopify's GraphiQL App installed on the store where I am trying to create the checkout.
This is my mutation, where the only thing I changed was the variantId so it matches one on my store:
mutation {
checkoutCreate(input: {
lineItems: [{ variantId: "gid://shopify/ProductVariant/46037988422", quantity: 1 }]
}) {
checkout {
id
webUrl
lineItems(first: 5) {
edges {
node {
title
quantity
}
}
}
}
}
}
This is the response I'm getting from Shopify:
{
"errors": [
{
"message": "Field 'checkoutCreate' doesn't exist on type 'Mutation'",
"locations": [
{
"line": 2,
"column": 3
}
],
"path": [
"mutation",
"checkoutCreate"
],
"extensions": {
"code": "undefinedField",
"typeName": "Mutation",
"fieldName": "checkoutCreate"
}
}
The weird thing is that obviously checkoutCreate IS a mutation, according to Shopify. See the link to the page here
Then I noticed, that the mutation on that page is different. So I'm trying that version, without a variable like this:
mutation checkoutCreate(input: {
lineItems: [{ variantId: "gid://shopify/ProductVariant/46037988422", quantity: 1 }]
}) {
checkout {
id
}
checkoutUserErrors {
code
field
message
}
}
And now the error I'm getting back is:
{
"errors": [
{
"message": "Parse error on \"input\" (INPUT) at [1, 25]",
"locations": [
{
"line": 1,
"column": 25
}
]
}
]
}
Finally I tried this version with a variable and it also failed:
mutation checkoutCreate($input: CheckoutCreateInput!) {
checkoutCreate(input: $input) {
checkout {
id
}
checkoutUserErrors {
code
field
message
}
}
}
{
"input": {
lineItems: [{ variantId: "gid://shopify/ProductVariant/46037988422", quantity: 1 }]
}
}
The error here was:
{
"errors": [
{
"message": "Parse error on \"input\" (STRING) at [15, 3]",
"locations": [
{
"line": 15,
"column": 3
}
]
}
]
}
On top of all this, Shopify has interactive docs in their GraphiQL App.. and it does NOT list checkoutCreate as an available mutation. See this screenshot: https://nimb.ws/af4iHx

Answer 1

I believe your input is parsed as JSON, so try putting quotes even around the nested properties of your mutation variables when testing.
{
"input": {
"lineItems": [{ "variantId": "gid://shopify/ProductVariant/46037988422",
"quantity": 1 }]
}
}

Answer 2

The mutations that complete checkouts are only available for sales channels. These apps must be public. So it might not work if you are creating a private app.
https://shopify.dev/tutorials/create-a-checkout-with-storefront-api
https://shopify.dev/tutorials/authenticate-a-public-app-with-oauth#turn-an-app-into-a-sales-channel