Node.js (GraphQL Request)

Step 1. Getting started

Step 1.1. Overview

After the initial setup in Step 1, you'll have the following APIs at your fingertips.

main.js

import { gql } from "graphql-request";
import { DeliveryTrackerGraphQLClient } from "./DeliveryTrackerGraphQLClient.js";

// Create a Client that connects to the DeliveryTracker Server.
const client = new DeliveryTrackerGraphQLClient(
  "[YOUR_CLIENT_ID]",
  "[YOUR_CLIENT_SECRET]"
);

// Example query to get the time and code of a recent event
// There are many other queries, which can be used to retrieve various information.
// Please refer to the documentation and API schema on the official site
const trackQuery = gql`
  query GetTrackLastEvent($carrierId: ID!, $trackingNumber: String!) {
    track(carrierId: $carrierId, trackingNumber: $trackingNumber) {
        lastEvent {
            time
            status {
                code
            }
        }
    }
  }
`;

// Call the DeliveryTracker API.
const response = await client.request(trackQuery, {
  carrierId: "kr.cjlogistics",
  trackingNumber: "1234567890",
});
console.log(response);

Step 1.2. Add dependencies

This document walks you through how to use the Delivery Tracker API using graphql-request. To do this, we first install graphql-request.

npm add graphql-request graphql

Step 1.3. Add Transport class

The GraphQLClient built into graphql-request does not provide Delivery Tracker Auth out of the box. For authentication, add a DeliveryTrackerGraphQLClient that inherits from GraphQLClient and implements Delivery Tracker Auth.

DeliveryTrackerGraphQLClient.js

import { GraphQLClient } from "graphql-request";

class DeliveryTrackerGraphQLClient extends GraphQLClient {
  constructor(clientId, clientSecret) {
    super("https://apis.tracker.delivery/graphql", {
      fetch: (input, init) => this._fetch(input, init),
    });
    this._accessToken = null;
    this._credentials = "Basic " + btoa(`${clientId}:${clientSecret}`);
  }

  async _fetch(input, init) {
    let response = await fetch(input, {
      ...init,
      headers: {
        ...init.headers,
        "Authorization": `Bearer ${await this.getAccessToken()}`,
      }
    });

    let responseBody = await response.text();

    if(this._hasUnauthenticatedError(JSON.parse(responseBody))) {
      response = await fetch(input, {
        ...init,
        headers: {
          ...init.headers,
          "Authorization": `Bearer ${await this.getAccessToken(true)}`,
        }
      });
      responseBody = await response.text();
    }

    return {
      ok: response.ok,
      status: response.status,
      headers: response.headers,
      text: async () => responseBody,
    };
  }

  _hasUnauthenticatedError(responseBody) {
    if (!Array.isArray(responseBody.errors)) {
      return false;
    }
    for (const error of responseBody.errors) {
      try {
        if (error.extensions?.code === "UNAUTHENTICATED") {
          return true;
        }
      } catch (e) {}
    }
    return false;
  }

  async getAccessToken(forceFetchNewAccessToken = false) {
    if (this._accessToken === null || forceFetchNewAccessToken) {
      this._accessToken = await this._fetchNewAccessToken();
    }
    return this._accessToken;
  }

  async _fetchNewAccessToken() {
    const authResponse = await fetch(
      "https://auth.tracker.delivery/oauth2/token",
      {
        method: "POST",
        headers: {
          "Authorization": This._credentials,
          "Content-Type": "application/x-www-form-urlencoded",
        },
        body: "grant_type=client_credentials",
      },
    );
    if(authResponse.status >= 400) {
      throw new Error(`Auth error: http response code=${authResponse.status} body=${await authResponse.text()}`);
    }
    try {
      const authResponseBody = await authResponse.json();
      const accessToken = authResponseBody.access_token;
      if (typeof accessToken !== "string") {
        throw new Error('typeof accessToken !== "string"');
      }
      return accessToken;
    } catch (e) {
      throw new Error("The access_token field was not found.", { cause: e });
    }
  }
}

export { DeliveryTrackerGraphQLClient };

Step 1.4. Execute your first query

"Step 1.1. Write the main.js code described in "Overview" and run main.js to get the API working.