BaseHttpLink

Get GraphQL results over a network using HTTP fetch


BaseHttpLink is a terminating link that sends a GraphQL operation to a remote endpoint over HTTP. It serves as a base link to HttpLink.

BaseHttpLink supports both POST and GET requests, and you can configure HTTP options on a per-operation basis. You can use these options for authentication, persisted queries, dynamic URIs, and other granular updates.

note
Prefer using HttpLink over BaseHttpLink. Use BaseHttpLink when you need to disable client awareness features and would like to tree-shake the implementation of ClientAwarenessLink out of your app bundle.
TypeScript
1 import { BaseHttpLink } from "@apollo/client/link/http";
2
3 const link = new BaseHttpLink({
4   uri: "http://localhost:4000/graphql",
5   headers: {
6     authorization: `Bearer ${token}`,
7   },
8 });

Constructor signature

TypeScript
1constructor(
2  options: BaseHttpLink.Options = {}
3): BaseHttpLink

Usage

See the HttpLink documentation for more information on how to use BaseHttpLink.

Types

Options passed to BaseHttpLink through request context. Previous non-terminating links in the link chain also can set these values to customize the behavior of BaseHttpLink for each operation.

note
Some of these values can also be provided to the HttpLink constructor. If a value is provided to both, the value in context takes precedence.
Properties
Name / Type
Description
RequestCredentials

The credentials policy to use for each fetch call.

Any overrides of the fetch options argument to pass to the fetch call.

An object containing options to use for each call to fetch. If a particular option is not included in this object, the default value of that option is used.

note
If you set fetchOptions.method to GET, HttpLink follows standard GraphQL HTTP GET encoding.

See available options

Record<string, string>

An object representing headers to include in every HTTP request.

JSON
1 {
2   "Authorization": "Bearer 1234"
3 }
BaseHttpLink.HttpOptions

An object that configures advanced functionality, such as support for persisted queries.

string | BaseHttpLink.UriFunction

The URL of the GraphQL endpoint to send requests to. Can also be a function that accepts an ApolloLink.Operation object and returns the string URL to use for that operation.

Options passed to BaseHttpLink through the http property of a request context.

Properties
Name / Type
Description

A list of additional accept headers to include in the request, as defined in http://datatracker.ietf.org/doc/html/rfc7231#section-5.3.2

JSON
1 ["application/custom+json;q=1.0"]

If true, includes the extensions field in operations sent to your GraphQL endpoint.

If false, the GraphQL query string is not included in the request. Set this option if you're sending a request that uses a persisted query.

If true, header names won't be automatically normalized to lowercase. This allows for non-http-spec-compliant servers that might expect capitalized header names.

Options provided to the BaseHttpLink constructor.

note
Some of these options are also available to override in request context. Context options override the options passed to the constructor. Treat these options as default values that are used when the request context does not override the value.
Properties
Name / Type
Description
RequestCredentials

The credentials policy to use for each fetch call.

typeof fetch

A function to use instead of calling the Fetch API directly when sending HTTP requests to your GraphQL endpoint. The function must conform to the signature of fetch.

By default, the Fetch API is used unless it isn't available in your runtime environment.

See Customizing fetch.

Any overrides of the fetch options argument to pass to the fetch call.

An object containing options to use for each call to fetch. If a particular option is not included in this object, the default value of that option is used.

note
If you set fetchOptions.method to GET, HttpLink follows standard GraphQL HTTP GET encoding.

See available options

Record<string, string>

An object representing headers to include in every HTTP request.

JSON
1 {
2   "Authorization": "Bearer 1234"
3 }

If true, includes the extensions field in operations sent to your GraphQL endpoint.

If true, unused variables from the operation will not be stripped from the request and will instead be sent to the GraphQL endpoint.

Read more...

Unused variables are likely to trigger server-side validation errors, per http://spec.graphql.org/draft/#sec-All-Variables-Used. includeUnusedVariables can be useful if your server deviates from the GraphQL specification by not strictly enforcing that rule.

If true, header names won't be automatically normalized to lowercase. This allows for non-http-spec-compliant servers that might expect capitalized header names.

BaseHttpLink.Printer

A function to use when transforming a GraphQL document into a string. It accepts an ASTNode (typically a DocumentNode) and the original print function as arguments, and is expected to return a string. This option enables you to, for example, use stripIgnoredCharacters to remove whitespace from queries.

By default the GraphQL print function is used.

TypeScript
1 import { stripIgnoredCharacters } from "graphql";
2
3 const httpLink = new HttpLink({
4   uri: "/graphql",
5   print: (ast, originalPrint) => stripIgnoredCharacters(originalPrint(ast)),
6 });
string | BaseHttpLink.UriFunction

The URL of the GraphQL endpoint to send requests to. Can also be a function that accepts an ApolloLink.Operation object and returns the string URL to use for that operation.

If true, the link uses an HTTP GET request when sending query operations to your GraphQL endpoint. Mutation operations continue to use POST requests. If you want all operations to use GET requests, set fetchOptions.method instead.

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