Rate Limits - Impulse Labs

The Impulse Labs API enforces a sliding window rate limit per user per 60-second period.

Limits by plan

Plan	Requests / 60 seconds
Pro	120
Team	300
Enterprise	1 000

Limits apply to validated inference requests — each call to POST /infer counts as one request against your limit.

Rate limit headers

Every response from POST /infer includes these headers:

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

Reading headers

curl -si -X POST "https://inference.impulselabs.ai/infer" \
  -H "Authorization: Bearer $IMPULSE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"deployment_id": "my-model", "inputs": {}}' \
  | grep -i x-ratelimit

# X-RateLimit-Limit: 120
# X-RateLimit-Remaining: 118
# X-RateLimit-Reset: 1708346460

Handling 429 Too Many Requests

When you exceed the limit, the API returns:

HTTP/1.1 429 Too Many Requests
Retry-After: 34
X-RateLimit-Limit: 120
X-RateLimit-Remaining: 0
X-RateLimit-Reset: 1708346460

{
  "valid": false,
  "error": "Rate limit exceeded",
  "limit": 120,
  "retry_after_seconds": 34
}

Recommended retry strategy

Read the Retry-After header and wait that many seconds before retrying.
Do not retry immediately in a tight loop — this will keep triggering the limit.
For batch workloads, spread requests over time or use exponential backoff.

Python — respect Retry-After

import time, requests

def safe_infer(session, payload, headers):
    while True:
        resp = session.post(
            "https://inference.impulselabs.ai/infer",
            json=payload,
            headers=headers,
        )
        if resp.status_code == 429:
            wait = int(resp.headers.get("Retry-After", 5))
            print(f"Rate limited. Retrying in {wait}s...")
            time.sleep(wait)
            continue
        resp.raise_for_status()
        return resp.json()

Upgrading your plan

If you consistently hit rate limits, consider upgrading to a higher plan at app.impulselabs.ai/billing. For custom limits or Enterprise pricing, contact us.

​Limits by plan

​Rate limit headers

​Reading headers

​Handling 429 Too Many Requests

​Recommended retry strategy

​Upgrading your plan

Limits by plan

Rate limit headers

Reading headers

Handling 429 Too Many Requests

Recommended retry strategy

Upgrading your plan