(Go) 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

Chilkat Go Downloads Go Package for Windows, MacOS, Linux, Alpine Linux, Solaris

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

    http := chilkat.NewHttp()
    var success bool

    // 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 := chilkat.NewHttpRequest()
    req.AddParam("grant_type","client_credentials")
    req.AddParam("client_id","123456789")
    req.AddParam("client_secret","A1B2C3D4E5")
    req.AddParam("scope","ResourceA+ResourceB+ResourceC")

    resp := http.PostUrlEncoded("https://apis.usps.com/oauth2/v3/token",req)
    if http.LastMethodSuccess() == false {
        fmt.Println(http.LastErrorText())
        http.DisposeHttp()
        req.DisposeHttpRequest()
        return
    }

    sbResponseBody := chilkat.NewStringBuilder()
    resp.GetBodySb(sbResponseBody)

    jResp := chilkat.NewJsonObject()
    jResp.LoadSb(sbResponseBody)
    jResp.SetEmitCompact(false)

    fmt.Println("Response Body:")
    fmt.Println(*jResp.Emit())

    respStatusCode := resp.StatusCode()
    fmt.Println("Response Status Code = ", respStatusCode)
    if respStatusCode >= 400 {
        fmt.Println("Response Header:")
        fmt.Println(resp.Header())
        fmt.Println("Failed.")
        resp.DisposeHttpResponse()
        http.DisposeHttp()
        req.DisposeHttpRequest()
        sbResponseBody.DisposeStringBuilder()
        jResp.DisposeJsonObject()
        return
    }

    resp.DisposeHttpResponse()

    // 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": "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"
    // }

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

    access_token := jResp.StringOf("access_token")
    token_type := jResp.StringOf("token_type")
    issued_at := jResp.IntOf("issued_at")
    expires_in := jResp.IntOf("expires_in")
    status := jResp.StringOf("status")
    scope := jResp.StringOf("scope")
    issuer := jResp.StringOf("issuer")
    client_id := jResp.StringOf("client_id")
    application_name := jResp.StringOf("application_name")
    api_products := jResp.StringOf("api_products")
    public_key := jResp.StringOf("public_key")

    http.DisposeHttp()
    req.DisposeHttpRequest()
    sbResponseBody.DisposeStringBuilder()
    jResp.DisposeJsonObject()