Keystone class

> This is the last active development release of this package as Keystone 5 is now in a 6 to 12 month active maintenance phase. For more information please read our Keystone 5 and beyond post.

Usage

``javascript
const { Keystone } = require('@open-keystone/keystone');

const keystone = new Keystone({
adapter,
appVersion,
cookie,
cookieSecret,
defaultAccess,
onConnect,
queryLimits,
sessionStore,
schemaNames,
});
`

$3

Configure the application version, which can be surfaced via HTTP headers or GraphQL.

The version can be any string value you choose to use for your system. If addVersionToHttpHeaders is true then all requests will have the header X-Keystone-App-Version set. The version can also be queried from the GraphQL API as { appVersion }. You can control whether this is exposed in your schema using access, which can be either a boolean, or an object with schemaName keys and boolean values.

`javascript
const keystone = new Keystone({
appVersion: {
version: '1.0.0',
addVersionToHttpHeaders: true,
access: true,
},
});
`

#### Why don't we just use access to control the HTTP header?

> We want to attach the HTTP header at the very top of the middleware stack, so if something gets rejected we can at least be sure of the system version that did the rejecting. This happens well before we have worked out which schema the person is trying to access, and therefore our access control isn’t ready to be used. Also, the access control that we set up is all about controlling access to the GraphQL API, and HTTP headers are a Different Thing, so even if it was technically possible to use the same mechanism, it really makes sense to decouple those two things.

$3

_Default:_ see Usage.

A description of the cookie properties is included in the express-session documentation.

#### secure

A secure cookie is only sent to the server with an encrypted request over the HTTPS protocol. If secure is set to true (as is the default with a production build) for a KeystoneJS project running on a non-HTTPS server (such as localhost), you will not be able to log in. In that case, be sure you set secure to false. This does not affect development builds since this value is already false.

You can read more about secure cookies on the MDN web docs.

#### Usage

`javascript
const keystone = new Keystone({
/ ...config /
cookie: {
secure: process.env.NODE_ENV === 'production', // Default to true in production
maxAge: 1000 60 60 24 30, // 30 days
sameSite: false,
},
});
`

$3

The secret used to sign session ID cookies. In production mode (process.env.NODE_ENV === 'production') this option is required. In development mode, if undefined, a random cookieSecret will be generated each time Keystone starts (this will cause sessions to be reset between restarts).

$3

_Default:_

`js
{
list: true,
field: true,
custom: true
}
`

Default list and field access. See the Access Control page for more details.

$3

_Default:_ undefined

Callback function that executes once keystone.connect() is complete. Takes no arguments.

$3

Configures global query limits.

These should be used together with list query limits.

`javascript
const keystone = new Keystone({
queryLimits: {
maxTotalResults: 1000,
},
});
`

- maxTotalResults: limit of the total results of all relationship subqueries

Note that maxTotalResults applies to the total results of all relationship queries separately, even if some are nested inside others.

$3

Sets the Express server's session middleware. This should be configured before deploying your app.

This example uses the connect-mongo middleware, but you can use any of the stores that work with express session.

`javascript
const expressSession = require('express-session');
const MongoStore = require('connect-mongo')(expressSession);

const keystone = new Keystone({
sessionStore: new MongoStore({ url: 'mongodb://localhost/my-app' }),
});
`

$3

_Default:_ ['public']

Methods

| Method | Description |
| --------------------- | ---------------------------------------------------------------------------- |
| connect | Manually connect to Adapter. |
| createAuthStrategy | Creates a new authentication middleware instance. |
| createList | Add a list to the Keystone schema. |
| disconnect | Disconnect from the adapter. |
| extendGraphQLSchema | Extend keystones generated schema with custom types, queries, and mutations. |
| prepare | Manually prepare Keystone middlewares. |
| createContext | Create a context object that can be used with executeGraphQL(). |
| executeGraphQL | Execute a server-side GraphQL operation within the given context. |

$3

Manually connect Keystone to the adapter. See Custom Server.

`javascript allowCopy=false showLanguage=false
keystone.connect();
`

> Note: keystone.connect() is only required for custom servers. Most example projects use the keystone start command to start a server and automatically connect.

$3

Creates a new authentication middleware instance. See:

- Authentication guide
- Authentication API docs

`javascript allowCopy=false showLanguage=false
const authStrategy = keystone.createAuthStrategy({...});
`

$3

Registers a new list with Keystone and returns a Keystone list object. See:

- Adding lists tutorial
- Data modelling guide

`javascript allowCopy=false showLanguage=false
keystone.createList('Posts', {...});
`

#### Config

| Option | Type | Default | Description |
| --------- | -------- | ------- | ------------------------------------------------------------------------------------------- |
| listKey | String | null | The name of the list. This should be singular, E.g. 'User' not 'Users'. |
| config | Object | {} | The list config. See the create list API docs for more details. |

$3

Disconnect the adapter.

$3

Extends keystones generated schema with custom types, queries, and mutations.

`javascript
keystone.extendGraphQLSchema({
types: [{ type: 'type MyType { original: Int, double: Float }' }],
queries: [
{
schema: 'double(x: Int): MyType',
resolver: (_, { x }) => ({ original: x, double: 2.0 * x }),
},
],
mutations: [
{
schema: 'triple(x: Int): Int',
resolver: (_, { x }) => 3 * x,
},
],
});
`

See the Custom schema guide for more information on utilizing custom schema.

#### Config

| Option | Type | Description |
| --------- | ------- | ---------------------------------------------------------------------------------------------- |
| types | array | A list of objects of the form { type, access } where the type string defines a GraphQL type. |
| queries | array | A list of objects of the form { schema, resolver, access }. |
| mutations | array | A list of objects of the form { schema, resolver, access }. |

- The schema for both queries and mutations should be a string defining the GraphQL schema element for the query/mutation, e.g.

`javascript
{
schema: 'getBestPosts(author: ID!): [Post]',
}
`

- The resolver for both queries and mutations should be a resolver function with following signature:

`javascript
{
resolver: (parent, args, context, info, extra) => {},
}
`

For more information about the first four arguments, please see the Apollo docs. The last argument extra is an object that contains the following property:

| Name | Description |
| -------- | -------------------------------------------------- |
| access | Access control information about the current user. |

- The access argument for types, queries, and mutations are all either boolean values which are used at schema generation time to include or exclude the item from the schema, or a function which must return boolean.
- See the Access control API docs for more details.

$3

Manually prepare middlewares. Returns a promise representing the processed middlewares. They are available as an array through the middlewares property of the returned object.

#### Usage

`javascript
const { middlewares } = await keystone.prepare({
apps,
dev: process.env.NODE_ENV !== 'production',
});
`

#### Config

| Option | Type | default | Description |
| ------------- | --------- | ------------------------------------- | ------------------------------------------------------------------------------------------------------------------- |
| apps | Array | [] | An array of 'Apps' which are express middleware. |
| cors | Object | { origin: true, credentials: true } | CORS options passed to the cors npm module |
| dev | Boolean | false | Sets the dev flag in Keystone' express middleware. |
| distDir | String | dist | The build directory for keystone. |
| pinoOptions | Object | undefined | Logging options passed to the express-pino-logger npm module |

$3

Create a context object that can be used with executeGraphQL().

#### Usage

`javascript
const { gql } = require('apollo-server-express');

// Create a context which can execute GraphQL operations with no access control
const context = keystone.createContext().sudo()

// Execute a GraphQL operation with no access control
const { data, errors } = await keystone.executeGraphQL({ context, query: gql ... , variables: { ... }})
`

#### Config

| Option | Type | default | Description |
| ------------------- | --------- | -------- | -------------------------------------------------------------------------------------------- |
| schemaName | String | public | The name of the GraphQL schema to execute against. |
| authentication | Object | {} | { item: { id }, listAuthKey: "" }. Specifies the item to be used in access control checks. |
| skipAccessControl | Boolean | false | Set to true to skip all access control checks. |

$3

Execute a server-side GraphQL query within the given context.

#### Usage

`javascript
const { gql } = require('apollo-server-express');

// Create a context which can execute GraphQL operations with no access control
const context = keystone.createContext().sudo()

// Execute a GraphQL operation with no access control
const { data, errors } = await keystone.executeGraphQL({ context, query: gql ... , variables: { ... }})
`

#### Config

| Option | Type | default | Description |
| ----------- | -------- | -------------------------- | ------------------------------------------------------- |
| context | Array | keystone.createContext() | A context object to be used by the GraphQL resolvers. |
| query | Object | undefined | The GraphQL operation to execute. |
| variables | Object | undefined` | The variables to be passed to the GraphQL operation. |