Streaming job dispatch is now generally available

Agents running buildkite-agent start now receive jobs in sub-second time, with no configuration changes necessary. Agent v3.122.0 replaces the polling-based dispatch with a persistent streaming connection, enabled by default.

What changed

Agent v3.122.0 changes the default agent API endpoint to agent-edge.buildkite.com, a new Go-based edge service that maintains a ConnectRPC stream to each connected agent. When a job is dispatched, it's pushed to agents over this stream rather than waiting for the next poll.

Why this matters

Previously, agents checked for work by polling every 10 seconds, plus random jitter to avoid synchronized requests across fleets. A job dispatched right after a poll could wait up to 20 seconds before that agent checks in again. Across a pipeline with many steps, that wait compounds.

With streaming dispatch, job acceptance latency drops to under 1 second. For an average build, that can save minutes of unnecessary wait time - resulting in faster and more efficient builds.

Availability

This is now the default for all agents running buildkite-agent start, including those on the Elastic CI Stack for AWS.

Buildkite Hosted Agents, Agent Stack for Kubernetes, and workflows using --acquire-job use different dispatch mechanisms and don't benefit from this change.

Upgrade to Agent v3.122.0 to get streaming dispatch by default. We'd love to hear how it goes! Reach out to support@buildkite.com with any feedback.