check api key on client init

client.go

@@ -3,6 +3,7 @@ package cohere
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"io"
 	"net/http"
 	"path"
@@ -16,21 +17,41 @@ type Client struct {
 }
 
 const (
-	endpointGenerate   = "/generate"
-	endpointChooseBest = "/choose-best"
-	endpointEmbed      = "/embed"
-	endpointLikelihood = "/likelihood"
+	endpointGenerate   = "generate"
+	endpointChooseBest = "choose-best"
+	endpointEmbed      = "embed"
+	endpointLikelihood = "likelihood"
+
+	endpointCheckAPIKey = "check-api-key"
 )
 
+type CheckAPIKeyResponse struct {
+	Valid bool
+}
+
 // Public functions
 
-func CreateClient(apiKey string) *Client {
-	return &Client{
+func CreateClient(apiKey string) (*Client, error) {
+	client := &Client{
 		APIKey:  apiKey,
 		BaseURL: "https://api.cohere.ai/",
 		Client:  *http.DefaultClient,
 		Version: "2021-11-08",
 	}
+
+	res, err := client.CheckAPIKey()
+	if err != nil {
+		return nil, err
+	}
+
+	ret := &CheckAPIKeyResponse{}
+	if err := json.Unmarshal(res, ret); err != nil {
+		return nil, err
+	}
+	if !ret.Valid {
+		return nil, errors.New("invalid api key")
+	}
+	return client, nil
 }
 
 // Client methods
@@ -49,6 +70,7 @@ func (c *Client) post(model string, endpoint string, body interface{}) ([]byte,
 
 	req.Header.Set("Authorization", "BEARER "+c.APIKey)
 	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Request-Source", "go-sdk")
 	if len(c.Version) > 0 {
 		req.Header.Set("Cohere-Version", c.Version)
 	}
@@ -74,6 +96,40 @@ func (c *Client) post(model string, endpoint string, body interface{}) ([]byte,
 	return buf, nil
 }
 
+func (c *Client) CheckAPIKey() ([]byte, error) {
+	url := c.BaseURL + endpointCheckAPIKey
+	req, err := http.NewRequest("POST", url, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	req.Header.Set("Authorization", "BEARER "+c.APIKey)
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Request-Source", "go-sdk")
+	if len(c.Version) > 0 {
+		req.Header.Set("Cohere-Version", c.Version)
+	}
+	res, err := c.Client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+
+	defer res.Body.Close()
+	buf, err := io.ReadAll(res.Body)
+	if err != nil {
+		return nil, err
+	}
+	if res.StatusCode != 200 {
+		e := &APIError{}
+		if err := json.Unmarshal(buf, e); err != nil {
+			return nil, err
+		}
+		e.StatusCode = res.StatusCode
+		return nil, e
+	}
+	return buf, nil
+}
+
 // Generates realistic text conditioned on a given input.
 // See: https://docs.cohere.ai/generate-reference
 // Returns a GenerateResponse object.

client_test.go

@@ -1,9 +1,7 @@
 package cohere
 
 import (
-	"errors"
 	"os"
-	"reflect"
 	"testing"
 )
 
@@ -17,22 +15,23 @@ func init() {
 
 func TestErrors(t *testing.T) {
 	t.Run("Invalid api key", func(t *testing.T) {
-		co := CreateClient("")
-		_, err := co.Generate("small", GenerateOptions{
-			Prompt:      "",
-			MaxTokens:   10,
-			Temperature: 0.75,
-		})
+		co, err := CreateClient("")
+		if co != nil {
+			t.Error("expected nil client, got client")
+		}
 		if err == nil {
-			t.Errorf("expected error, got nil")
-		} else if !errors.Is(err, &APIError{}) {
-			t.Errorf("expected ApiError, got %s", reflect.TypeOf(err))
+			t.Error("expected error, got nil")
+		} else if err.Error() != "invalid api key" {
+			t.Errorf("expected invalid api key, got %s", err.Error())
 		}
 	})
 }
 
 func TestGenerate(t *testing.T) {
-	co := CreateClient(apiKey)
+	co, err := CreateClient(apiKey)
+	if err != nil {
+		t.Error(err)
+	}
 
 	t.Run("Generate basic", func(t *testing.T) {
 		_, err := co.Generate("medium", GenerateOptions{
@@ -62,7 +61,10 @@ func TestGenerate(t *testing.T) {
 }
 
 func TestChooseBest(t *testing.T) {
-	co := CreateClient(apiKey)
+	co, err := CreateClient(apiKey)
+	if err != nil {
+		t.Error(err)
+	}
 
 	t.Run("ChooseBest", func(t *testing.T) {
 		_, err := co.ChooseBest("small", ChooseBestOptions{
@@ -78,7 +80,10 @@ func TestChooseBest(t *testing.T) {
 }
 
 func TestEmbed(t *testing.T) {
-	co := CreateClient(apiKey)
+	co, err := CreateClient(apiKey)
+	if err != nil {
+		t.Error(err)
+	}
 
 	t.Run("Embed", func(t *testing.T) {
 		texts := []string{"hello", "goodbye"}
@@ -94,7 +99,10 @@ func TestEmbed(t *testing.T) {
 }
 
 func TestLikelihood(t *testing.T) {
-	co := CreateClient(apiKey)
+	co, err := CreateClient(apiKey)
+	if err != nil {
+		t.Error(err)
+	}
 
 	t.Run("Likelihood", func(t *testing.T) {
 		text := "so I crept up the basement stairs and BOOOO!"

example/main.go

@@ -14,7 +14,11 @@ func main() {
 		os.Exit(1)
 	}
 
-	co := cohere.CreateClient(apiKey)
+	co, err := cohere.CreateClient(apiKey)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
 
 	prompt := "What is your"
 	res, err := co.Generate("medium", cohere.GenerateOptions{