Listen Notes API

Listen Notes has been the dependable search-and-metadata API for podcasts for the better part of a decade, and a quiet lot of other podcast products are built on top of it without advertising the fact. The catalogue is broad and covers most of the active podcast world.

The API is well-documented in a way that a lot of dev-tooling APIs aren't, the OpenAPI spec is available in a clean Markdown form that LLM agents and code generators can actually parse and reason about, and the free tier is high enough that most prototypes never need to pay anything during the experimentation phase. When you finally hit the limits, it's usually a sign that the project has graduated from prototype to production rather than a sign that the free tier was too tight.

Where Listen Notes stops being the obvious choice is around two specific needs that have become more important over time. First, the listener numbers Listen Notes surfaces are estimated rather than first-party, derived from a combination of chart positions, social signals, and other indirect measures, so attribution and audience-size questions can't be answered with the certainty a serious media buyer might want when committing real budget.

Second, the API pricing curve climbs faster than you'd hope once you cross into production-grade volumes, and the transcript depth doesn't match what Podscan offers for episodes-level monitoring use cases. Right tool for show discovery, metadata, episode search, and lightweight integrations; wrong tool for heavy transcript monitoring, precise listener measurement, or brand-mention alerting at scale.