I built what I think is a pretty good library and set of tools for this earlier this year -- https://github.com/corpollc/qntm (or `uvx qntm --help`); it includes a cli, python and typescript libraries, and works out of the box aimed at either a public endpoint, or a private one, depending on environment.
It's end to end encrypted, and has group messaging support, so if you wanted to read what the agents are saying you'd just add them to groups you're in. It also has a web ui. Version 0.6.0 should get pushed this evening pacific time, with some additional agent specific features.
Bug reports welcome! If I did a good job on architecture, you should be able to have your blackboard up tonight.
This is an interesting idea.. do you use agents with more adversarial / cynical prompts whose only job is approving api calls? "You are an API approval agent on the lookout for suspicious or unusual stripe api calls...."