An ingest endpoint is the public address an encoder pushes to. It terminates the contribution protocol (RTMP, SRT, RIST, WHIP, RTSP), demultiplexes audio and video, sometimes runs initial validation (format, bitrate, alignment), and forwards to the next stage — typically a transcoder for live, or a packager and origin for pass-through workflows. In a managed live service (Mux, Cloudflare Stream, AWS Elemental MediaLive) ingest is the API call you hit with a stream key.
Ingest is hard for three reasons. First, it has to terminate adversarial protocols — encoders sometimes send malformed RTMP timestamps, broken H.264 NAL units or wrong PTS/DTS pairs, and the ingest must reject cleanly without taking the whole service down. Second, it has to handle huge spikes — when a major event starts, thousands of streams may try to connect within a minute, and capacity has to scale. Third, it has to authenticate — a stream key in the URL is the usual mechanism, sometimes augmented with signed tokens, IP allowlists and per-event quotas.
The big trend of 2022–2026 is replacing RTMP with SRT and WHIP as the default ingest. RTMP is single-threaded, single-bitrate, TCP-based with poor recovery on lossy links. SRT and WHIP both run on UDP, recover from loss without ballooning latency, and integrate cleanly with cloud autoscaling. Mux, Cloudflare and most modern live services accept all three at the same endpoint and let the encoder choose.
