Set EXT-X-VERSION to 10 or higher in the media playlist to unlock LL-HLS tags
Add EXT-X-SERVER-CONTROL with CAN-BLOCK-RELOAD=YES and a PART-HOLD-BACK value (typically 3x the part target duration) to signal blocking reload support
Add EXT-X-PART-INF with PART-TARGET set to the partial segment duration (commonly 200–400 ms) near the top of the playlist
Emit EXT-X-PART tags for each partial segment near the live edge; include EXT-X-PRELOAD-HINT TYPE=PART pointing to the next expected partial segment so clients can request it in advance
On the origin server, hold the blocking playlist reload response until the requested playlist sequence or part is available, then flush it — this eliminates the polling delay
Known gotchas
EXT-X-PRELOAD-HINT must appear only once per playlist and must point to a resource that will be available 'at line speed'; a stale hint causes the player to buffer indefinitely
CDN cacheability conflicts with blocking reloads — use Cache-Control: no-store on playlist responses and ensure the CDN passes _HLS_msn/_HLS_part query parameters to the origin
PART-HOLD-BACK must be at least 3x PART-TARGET per the spec; setting it lower causes aggressive polling that defeats the latency benefit
Give your agent this knowledge — and 200+ more routes
One MCP install gives any agent live access to the full route map, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp