Substack · Rate Limits
Substack Rate Limits
Substack Rate Limits is the rate-limit profile for Substack on the APIs.io network.
The provider publishes no rate limits that could be read; the profile records that absence rather than inventing a ceiling.
Limit state is signalled in the observed and note response headers.
Tagged areas include Newsletters, Publishing, Creator Economy, Subscription, and Email.
0 Limits
observednote
Transcribed from the provider's documentation on 2026-08-13 — substack.com/api-tos.
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Limits
Substack publishes no rate limits that could be read; the profile records that absence rather than inventing a ceiling.
Substack states that rate limits exist but publishes no number, no window, no scope and no header. Section 5 of the Developer API Terms of Use reads: "Your use of the API is subject to rate limits, quotas, and other technical restrictions as determined by Substack in its sole discretion. You agree not to circumvent or attempt to bypass such restrictions. Substack may modify, suspend, or terminate API access or limits at any time." That is a policy, not a limit — an integrator cannot size a workload against it, and an agent has no runtime signal to back off on.
NewslettersPublishingCreator EconomySubscriptionEmailPodcastsNotesMediaIndependent MediaPaid ContentMCPAgentsRSSAnalytics
Work with this as data
Every rate limit here is available over the APIs.io API and to AI agents over MCP.