HTTP interceptors

Apollo Kotlin supports multi platform HttpInterceptor very similar to OkHttp Interceptors. Use them to add authentication headers, log the network calls or anything else.

The interface is a single method. For an example, implementing an authentication interceptors can be done with:

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class AuthorizationInterceptor(val token: String) : HttpInterceptor {
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  override suspend fun intercept(request: HttpRequest,  chain: HttpInterceptorChain): HttpResponse {
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    return chain.proceed(request.newBuilder().addHeader("Authorization", "Bearer $token").build())
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  }
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}

Then add the interceptor to your HttpNetworkTransport:

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val apolloClient = ApolloClient.Builder()
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    .serverUrl("https://example.com/graphql")
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    .addHttpInterceptor(AuthorizationInterceptor(token))
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    .build()

By default, Apollo Kotlin comes with ClientAwarenessInterceptor and LoggingInterceptor.

Reusing OkHttp interceptors on JVM only projects

If your project is a JVM only project and you already have an OkHttp Interceptor, you can also reuse it:

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val okHttpClient = OkHttpClient.Builder()
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    .addInterceptor(interceptor)
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    .build()
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val apolloClient = ApolloClient.Builder()
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    .serverUrl("https://example.com/graphql")
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    .okHttpClient(okHttpClient)
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    .build()

Edit on GitHub

Troubleshooting

Custom HTTP clients