# # Qvalia Developer tools Access APIs and technical requirements and get connected in no time. Our APIs and onboarding team ensures a swift integration into your systems and processes. Qvalia integrates with major ERPs and accounting software. ### API All Qvalia API’s are [REST](http://en.wikipedia.org/wiki/Representational_State_Transfer) based and we use both JSON and XML request and response payloads. All message formats are based upon [UBL]( https://en.wikipedia.org/wiki/Universal_Business_Language) and our JSON format is a representation of the XML called `UBL JSON` by [OASIS]( https://www.oasis-open.org) Open group. We strive to use the REST standards for response codes and “verbs” (e.g. GET and POST). The Qvalia API has two separate endpoints for our Production and a Test (Quality Assurance) environment. **You must obtain a [Qvalia](https://qvalia.com) account prior to using (or testing) the API!** ```javascript async function httpsPost(registrationNumber, data) { return new Promise(async (resolve, reject) => { const options = { hostname: 'api.qvalia.com', path: `/transaction/${registrationNumber}/invoices/outgoing`, port: 443, method: 'POST', headers: { 'Content-Type': 'application/json', Authorization: '412ee738......d3e469a7' } }; const body = []; const req = https.request(options, res => { res.on('data', d=> { body.push(d); }); res.on('end', () => { resolve(body); }); }); req.on('error', e => { reject(e); }); req.write(JSON.stringify(data)); req.end(); }); } ``` ```curl curl --request POST \ --url https://api.qvalia.com/transaction/registration_number/invoices/outgoing \ --header 'Authorization: 412ee738......d3e469a7' \ --header 'Content-Type: application/json' \ --data '{ "$": {.......} }' ``` ### Authentication We use API keys for the Authentication of requests. You can get your API key from our Support team and you’ll get a separate key and URL for Production and Test environments. All requests are using HTTPS with a minimum of TLS 1.2 ### Parameters Some of our API's has the possibility to provide parameters for e.g. filtering. These parameters are sent as a `query string` and the options are listed per endpoint under the technical API documentation. ### Error handling We offer various error codes based upon the type of error, along with a descriptive error message (in JSON or XML). Like any other API codes in the range of `2xx` is a successful request while a status of `4xx` indicates an error that occurred because of the data sent or a parameter missing/in error. In the `5xx` range indicate an error with our server/service and you should contact the Qvalia Support if you ever would end up getting any `5xx` code as response. ### Support You can always contact Qvalia Support through your Qvalia Sales representative or by using our Support e-mail (see your Qvalia Account for details).