{"version":"2.1.319","anchor":"worker-announce-response-protocol-version-can-now-be-null","canonical_anchor":"worker-announce-response-protocol-version-can-now-be-null","heading":"A worker's announce reply now reports no protocol version when it is incompatible","tier":"internal","area":"Sessions","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.319\/e\/worker-announce-response-protocol-version-can-now-be-null","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.319","markdown":"### A worker's announce reply now reports no protocol version when it is incompatible\n\nWhen a worker announces itself, the reply now gives the compatible protocol version, or null if the protocol is not compatible\n\n**What**\n\nWhen a worker announces itself to its host, the reply includes `protocol_version`. It is now the compatible version, or null when the protocol is not compatible. Before, it was always the protocol version as given. The protocol details are now also logged.\n\n**Why**\n\nThis changes the handshake between a worker and its host: a null `protocol_version` now means the two cannot work together.\n\n- Area: Sessions\n- Tier: Under the hood\n- Useful: 1\/5\n- Signal: 1\/5\n- Scope: individual\n- Heads-up: no"}