Hello @Verdant Spark Which Programming language you are using to call the API? Is it possible to share the code to check where is the issue?

Hey there

Here’s the method; as I mentioned, I’m not actually questioning this, as it’s from a library we have in 3 other projects where it’s working just fine - there’s something about this particular klaviyo account - not sure if it’s because they’re not paying for the account yet, though that wouldn’t explain why it works from Postman.

The project is a CI4 framework:

/**
     * @param $template
     * @param $first_name
     * @param $passed_data array|null
     * @return mixed
     */
    public function klaviyoRender( $template, $first_name, ?array $passed_data = null ): mixed {
        $salutation = !$first_name || $first_name == '' ? '' : "Hi $first_name";
        $context = new stdClass();
        $context->salutation = $salutation;
        if ( $passed_data ) {
            foreach ( $passed_data as $key => $value ) {
                $context->$key = $value;
            }
        }
        $url = "https://a.klaviyo.com/api/template-render";
        $body =  
            'data' =>  
                'type'       => 'template',
                'id'         => $template,
                'attributes' => t
                    'context' => $context
                ]
            ]
        ];
        $client = Services::curlrequest();
        $auth = 'Klaviyo-API-Key ' . getenv( 'KLAVIYO_API_KEY' );
        $client->setHeader( 'Authorization', $auth );
        $client->setHeader( 'Accept', 'application/json' );
        $client->setHeader( 'Content-Type', 'application/json' );
        $client->setHeader( 'revision', '2024-07-15' );
        $client->setBody( json_encode( $body ) );

        try {
            $response = $client->request( 'post', $url, ( 'debug' => WRITEPATH . 'logs/curl_log.txt' ] );
            return json_decode( $response->getBody() )->data->attributes->html;
        }
        catch ( Exception $e ) {
            $this->logError($e);
            return false;
        }
    }

Hello @Verdant Spark  I don’t see any issue with code.
Did you try echoing the output of json_encode( $body )?

Yes - body is set as expected (you can see the body in the initial post)

Hmm, this is curious…

If this isn’t an encoding issue, I think it must be an API key or ID issue… are you sure that template with that ID exists in this environment? And can you triple-check the API key is the expected one for this klaviyo instance?

Do you get any more data in your error message? Typically a 400-level error will have some response body (or response text) that gives a little bit more information.

For example, my application hit a 409 error this morning and I got the following message returned in the error response.

text: '{"errors":"{"id":"9ab0eb5d-ab41-462d-afab-7168c146c0c3","status":409,"code":"duplicate_profile","title":"Conflict.","detail":"A profile already exists with one of these identifiers.","source":{"pointer":"/data/attributes"},"links":{},"meta":{"duplicate_profile_id":"XXX"}}]}';

Let us know.

Cheers,

Kevin.

API and template key are good - I’m using same in Postman and get a response The 400 doesn’t seem to come with any meaningful message that I can surface.

Just to make sure I’m not batshit crazy I also created a new API key and swapped it out to check. That has the same behaviour.

Weird!! Have you tried other API calls within this klaviyo instance? Simple calls like fetching a profile?

Super weird. I’ve swapped out my method for using the klaviyo SDK and now it’s working. So there’s a header which the API now expects to get (or not) which must have been causing it to fail. So random, and undocumented - but at least it’s working with the SDK instead. Sigh. There goes 6 hours of my life I’m not getting back.