(Unicode C) USPS OAuth2 Client Credentials

See more OAuth2 Examples

Get an OAuth2 access token for the United States Postal Service (USPS) REST API.

For more information, see https://developers.usps.com/api/81

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#include <C_CkHttpW.h>
#include <C_CkHttpRequestW.h>
#include <C_CkHttpResponseW.h>
#include <C_CkStringBuilderW.h>
#include <C_CkJsonObjectW.h>

void ChilkatSample(void)
    {
    HCkHttpW http;
    BOOL success;
    HCkHttpRequestW req;
    HCkHttpResponseW resp;
    HCkStringBuilderW sbResponseBody;
    HCkJsonObjectW jResp;
    int respStatusCode;
    const wchar_t *access_token;
    const wchar_t *token_type;
    int issued_at;
    int expires_in;
    const wchar_t *status;
    const wchar_t *scope;
    const wchar_t *issuer;
    const wchar_t *client_id;
    const wchar_t *application_name;
    const wchar_t *api_products;
    const wchar_t *public_key;

    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    http = CkHttpW_Create();

    // Implements the following CURL command:

    // curl -X POST https://apis.usps.com/oauth2/v3/token \
    //   -H "Content-Type: application/x-www-form-urlencoded" \
    //   -d "grant_type=client_credentials" \
    //   -d "client_id=123456789" \
    //   -d "client_secret=A1B2C3D4E5" \
    //   -d "scope=ResourceA+ResourceB+ResourceC"

    // Use the following online tool to generate HTTP code from a CURL command
    // Convert a cURL Command to HTTP Source Code

    req = CkHttpRequestW_Create();
    CkHttpRequestW_AddParam(req,L"grant_type",L"client_credentials");
    CkHttpRequestW_AddParam(req,L"client_id",L"123456789");
    CkHttpRequestW_AddParam(req,L"client_secret",L"A1B2C3D4E5");
    CkHttpRequestW_AddParam(req,L"scope",L"ResourceA+ResourceB+ResourceC");

    resp = CkHttpW_PostUrlEncoded(http,L"https://apis.usps.com/oauth2/v3/token",req);
    if (CkHttpW_getLastMethodSuccess(http) == FALSE) {
        wprintf(L"%s\n",CkHttpW_lastErrorText(http));
        CkHttpW_Dispose(http);
        CkHttpRequestW_Dispose(req);
        return;
    }

    sbResponseBody = CkStringBuilderW_Create();
    CkHttpResponseW_GetBodySb(resp,sbResponseBody);

    jResp = CkJsonObjectW_Create();
    CkJsonObjectW_LoadSb(jResp,sbResponseBody);
    CkJsonObjectW_putEmitCompact(jResp,FALSE);

    wprintf(L"Response Body:\n");
    wprintf(L"%s\n",CkJsonObjectW_emit(jResp));

    respStatusCode = CkHttpResponseW_getStatusCode(resp);
    wprintf(L"Response Status Code = %d\n",respStatusCode);
    if (respStatusCode >= 400) {
        wprintf(L"Response Header:\n");
        wprintf(L"%s\n",CkHttpResponseW_header(resp));
        wprintf(L"Failed.\n");
        CkHttpResponseW_Dispose(resp);
        CkHttpW_Dispose(http);
        CkHttpRequestW_Dispose(req);
        CkStringBuilderW_Dispose(sbResponseBody);
        CkJsonObjectW_Dispose(jResp);
        return;
    }

    CkHttpResponseW_Dispose(resp);

    // Sample JSON response:
    // (Sample code for parsing the JSON response is shown below)

    // {
    //   "access_token": "eyJraWQiOiIxMDEwMTAiLCJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiJ9.eyJzdWIiOiIiLCJhdWQiOiJhZGRyZXNzZXMgaW50ZXJuYXRpb25hbC1wcmljZXMgc3Vic2NyaXB0aW9ucyBwYXltZW50cyBwaWNrdXAgdHJhY2tpbmcgbGFiZWxzIHNjYW4tZm9ybXMgY29tcGFuaWVzIHNlcnZpY2UtZGVsaXZlcnktc3RhbmRhcmRzIGxvY2F0aW9ucyBpbnRlcm5hdGlvbmFsLWxhYmVscyBwcmljZXMiLCJhenAiOiJoeXI3YjN2Q1J0cFl0QUhNMWE4Y2RVcmt5eUZtTmtiZyIsIm9yZ2FuaXphdGlvbl9pZCI6IjAiLCJpc3MiOiJ1cm46XC9cL2FwaS51c3BzLmNvbSIsImV4cCI6MTY4MDkxNzc4NiwiaWF0IjoxNjgwODg4OTg2LCJqdGkiOiI3YjU5MzJlMS05NjIxLTQzZDAtYTMyNy0xMzIxYWVjNzJjZGYifQ.QzrUxlT2rG4jvYbMDGnk23j8ZYfHJcdXPKR9CbSmcKeVpURaHhEMpPB6K4x5ut3xxeEGSzeE5VRz8vixI4iqyHsD8rSdkLTPHy0iovUHOZQBAJVQ6hii9jpLhxUXmiTtH3jKzSj_f2fuNmZbIGhf-CR2FBeWF-aBPzEDEMV95nkCUMfW_Z2BmkbraSfvQZxkCO-cLrMAwlYcrzUtaJ7vnazeQB4sep5BBHBEvsa4kfq6_tz6BAKgv3R7cI2NkSv-wgy_IGoTjVCMTS8mJHGs_t8cWCO8-z4lxW1tUwIBKOCUDpmEEnGgiG6Sl0C_gGl4bZ5cDSl4IgPpcOVi9jZ7LA",
    //   "token_type": "Bearer",
    //   "issued_at": 1680888985929,
    //   "expires_in": 28799,
    //   "status": "approved",
    //   "scope": "addresses international-prices subscriptions payments pickup tracking labels scan-forms companies service-delivery-standards locations international-labels prices",
    //   "issuer": "api.usps.com",
    //   "client_id": "hyr7b3vCRtpYtAHM1a8cdUrkyyFmNkbg",
    //   "application_name": "Silver Shipper Developer",
    //   "api_products": "[Shipping-Silver]",
    //   "public_key": "LS0tLS1CRUdJTiBQVUJMSUMgS0VZLS0tLS0KTUlJQklqQU5CZ2txaGtpRzl3MEJBUUVGQUFPQ0FROEFNSUlCQ2dLQ0FRRUF4QWxwZjNSNEE1S0lwZnhJVWk1bgpMTFByZjZVZTV3MktzeGxSVzE1UWV0UzBjWGVxaW9OT2hXbDNaaVhEWEdKT3ZuK3RoY0NWVVQ3WC9JZWYvTENZCkhUWk1kYUJOdW55VHEwT2RNZmVkUU8zYUNKZmwvUnJPTHYyaG9TRDR4U1YxRzFuTTc1RTlRYitFZ1p0cmFEUXoKNW42SXRpMUMzOHFGMjU5NVRHUWVUemx3Wk1LQng1VTY2bGwzNzlkZ2plTUJxS3ppVHZHWEpOdVg5ZzRrRlBIaApTLzNERm9FNkVFSW8zUHExeDlXTnRaSm93VkRwQUVZZTQ3SU1UdXJDN2NGcXp2d3M1b1BDRHQ4c083N2lUdDN0Cm1vK3NrM2ExWnZSaGs2WUQ3Zkt1UldQVzFEYUM4dC9pazlnWnhqQndYNlZsSUhDRzRZSHlYejZteWdGV09jMmEKOVFJREFRQUIKLS0tLS1FTkQgUFVCTElDIEtFWS0tLS0t"
    // }

    // Sample code for parsing the JSON response...
    // Use the following online tool to generate parsing code from sample JSON:
    // Generate Parsing Code from JSON

    // Chilkat functions returning "const char *" return a pointer to temporary internal memory owned and managed by Chilkat.
    // See this example explaining how this memory should be used: const char * functions.

    access_token = CkJsonObjectW_stringOf(jResp,L"access_token");
    token_type = CkJsonObjectW_stringOf(jResp,L"token_type");
    issued_at = CkJsonObjectW_IntOf(jResp,L"issued_at");
    expires_in = CkJsonObjectW_IntOf(jResp,L"expires_in");
    status = CkJsonObjectW_stringOf(jResp,L"status");
    scope = CkJsonObjectW_stringOf(jResp,L"scope");
    issuer = CkJsonObjectW_stringOf(jResp,L"issuer");
    client_id = CkJsonObjectW_stringOf(jResp,L"client_id");
    application_name = CkJsonObjectW_stringOf(jResp,L"application_name");
    api_products = CkJsonObjectW_stringOf(jResp,L"api_products");
    public_key = CkJsonObjectW_stringOf(jResp,L"public_key");


    CkHttpW_Dispose(http);
    CkHttpRequestW_Dispose(req);
    CkStringBuilderW_Dispose(sbResponseBody);
    CkJsonObjectW_Dispose(jResp);

    }