Rate limits - Mithril

The gateway rate-limits per API key. Limits are split into two classes so that reads never starve your ability to place and cancel orders:

Class	Endpoints	Notes
Read	`GET` market data, positions, fills, risk stats	Higher ceiling
Write	`POST`/`PUT`/`DELETE` — orders, cancels, limit changes	Lower ceiling; the critical path

Mithril also absorbs each venue’s own limits server-side (Polymarket’s opaque Cloudflare pacing, Kalshi’s tiered token buckets), so you code against one predictable ceiling instead of two moving ones.

When you’re limited

A throttled request returns 429 with the standard error envelope:

{ "error": { "code": "rate_limited", "message": "rate limit exceeded", "request_id": "req_..." } }

Back off and retry. A simple exponential backoff with jitter is enough:

import time, random

def with_backoff(fn, tries=5):
    for i in range(tries):
        resp = fn()
        if resp.status_code != 429:
            return resp
        time.sleep(min(2 ** i, 8) + random.random())
    return resp

Prioritize cancels over new orders in your own client, and prefer worked orders over hand-rolled cancel/replace loops — Mithril’s execution engine paces child orders within venue limits for you.

Need higher throughput for a market-making strategy? Talk to us — limits are lifted per desk.

Errors Accounts

⌘I

​When you’re limited

When you’re limited