Rate Limits - Sendora

Current limits

Tier	Requests	Window
Default	300	Per minute, per API key
Bulk write endpoints	60	Per minute, per API key
Enrichment	20	Per minute, per workspace

Bulk write endpoints include: POST /lead-lists/{id}/enrich, POST /campaigns/{id}/leads (when lead_list_id is used).

Response headers

Every response includes rate-limit headers:

Header	Description
`X-RateLimit-Limit`	Maximum requests in the window
`X-RateLimit-Remaining`	Requests remaining in the current window
`X-RateLimit-Reset`	Unix timestamp when the window resets
`Retry-After`	Seconds to wait (present only on 429 responses)

Handling 429s

When you hit a rate limit:

Read the Retry-After header
Wait that many seconds before retrying
Use exponential backoff for sustained high-volume workloads

import httpx, time

def call_api(client, url):
    resp = client.get(url)
    if resp.status_code == 429:
        retry_after = int(resp.headers.get("Retry-After", "5"))
        time.sleep(retry_after)
        return call_api(client, url)
    return resp

Tips for staying under limits

Paginate efficiently, use the cursor param on list endpoints instead of fetching all pages at once
Batch lead enrollment, use lead_list_id instead of individual lead_ids arrays
Cache read responses, analytics and agent configs change infrequently
Webhook over polling, register webhook endpoints instead of polling the jobs or conversations API