The Veridion API uses the Token Bucket algorithm for rate-limiting purposes.
In simple terms, each API request results in the removal of 1 token from the bucket. Once the bucket runs out of tokens, any incoming requests will be declined with a 429 Too Many Requests HTTP status code until new tokens are added to the bucket.
Each API response includes the following rate-limiting headers:
X-RateLimit-Remaining: this numerical value shows the remaining tokens in the bucket. You can use this header to implement retry mechanisms if needed. A positive value means you can safely make a request without hitting the limit.X-RateLimit-Burst-Capacity: this header indicates the total number of concurrent requests you can make. Once you reach this limit, all tokens from the bucket are consumed, and you must wait for new tokens to be added.X-RateLimit-Replenish-Rate: this header specifies the number of tokens credited each second.
Default rate limit
The default API rate limit is 1 request per second. When this limit is exceeded, the API responds with a
429 Too Many RequestsHTTP status.