Integration boundary
Miss Blue offers a dedicated messaging line with API access and a team inbox. That combination gives developers a place to send work a model should not complete alone. Before choosing it, define what actually pauses automation when a teammate starts typing. The public feature list establishes the available surfaces, not a tested mutual-exclusion mechanism.
Capacity boundary
The current dedicated-line sale is $99 monthly. Homepage guidance is roughly 30 new contacts per line per day and 15 messages per minute. Store those as separate constraints in your planning. A queue that respects the per-minute rate can still exceed the daily new-contact guidance; connector-specific limits also need confirmation.
Acceptance case
Use a consenting test contact to ask a question outside the agent’s authority, then continue it from the Message Center. Check whether the agent can see the human answer and whether delayed events cause a second reply. These are proposed acceptance cases, not results from a test account. Agent Signal is published by the team that sells Miss Blue.