03: Routing + concurrency (sessionKey/lanes/queue)

Between “an inbound message arrives” and “an agent run starts”, the critical step is stable session routing and concurrency control.

You should be able to explain three properties:

• No cross-talk: groups/multi-account/multi-channel don’t leak context into each other
• Stable ordering: messages within the same session don’t reorder
• Safe parallelism: different sessions can run concurrently (with global limits)

sessionKey: the isolation primitive

sessionKey decides what belongs to the same session. It typically incorporates:

• channel type (DM/group/channel)
• account/device/connection instance
• thread/reply-chain context (when available)

See:

• Channel routing
• Session
• Session tool

lanes/queue: serial per session, parallel across sessions

Once a sessionKey is chosen:

• same sessionKey: serial execution (avoid concurrent session writes)
• different sessionKey: parallel execution (bounded by global limits)

See:

• Queue + lanes
• Session concurrency framework

Troubleshooting “cross-talk” or reordering

Debug from outside in:

1. verify routing/sessionKey choice
2. verify queue/lane settings (no unintended session collapsing)
3. return to logs/Control UI and follow one runId end-to-end

See:

• Logging
• Control UI