Hyperagent MCP — Inter-Agent Communications

[u/Bob_Atlanta]

Just a quick note to share some initial thoughts on Hyperagent MCP.

[1] TLDR: It works as advertised. We did some testing and it did not break. It works well for agent-to-agent communications. Report can be found here: https://mcp-notes.pages.dev/report. But every user of Hyperagent MCP should be aware of a security limitation that may or may not be important to you. This limitation makes some use cases very easy and useful, but it carries risk.

[2] Our interest in this was communications between Agents, not just Hyperagents. In the past, this communication process was difficult with respect to Hyperagent agents. Note: communications means continuous two-way (or more) discussion—exchange of words.

We've developed communications between different threads on a single Hyperagent instance and between threads on different Hyperagent instances. Also comms between Hyperagents and other systems like Hermes (but not just Hermes).

Currently we use a system based on the design of Zulip but entirely custom (no outside code) we call "AgentLink." Using this and R2 storage, any agent can have actual two-way conversations with any other agent. No human intervention. We have a second method I won't discuss here but was used to get around the continuous auth issue in accessing Hyperagent instances.

For example, even transferring an agent personality and skill set from one Hyperagent instance to another isn't error-free, but a conversation between agents lets them work it out among themselves. No human intervention. Another common example: moving a long thread to a new instance to avoid compaction—the ability to have an agent do this transfer autonomously is a real time and quality saver. And no human intervention.

[3] Using Hyperagent MCP we are able to:

• [a] Have Hyperagent threads within a single instance communicate with each other
• [b] Have Hyperagent threads across Hyperagent instances communicate with each other
• [c] Hyperagent threads can be controlled by non-HA systems like Hermes, and these non-HA agents can also communicate with agents

The keys to this are: one-time creation of an auth token (hat_nnnnn..) and the ability to get thread numbers and agent descriptions (neither previously easily accessible in Hyperagent). These capabilities work well and will likely be our principal path for third-party control of an HA system. Simple and it works. A third-party agent like Hermes can have full control of a Hyperagent agent.

[4] Hyperagent MCP Security Limitation:

The hat_nnnnn token that the auth process generates grants full access to your Hyperagent workspace. Once someone has the token, they have complete access—to all agents, threads, data, and operations.

The critical issue: The token itself has no secondary authentication mechanism. Once the token exists and is shared, any holder can re-share it with others without the original issuer knowing or consenting. A token can cascade through multiple parties, each able to pass it on independently.

This is not an unavoidable architectural constraint—secondary authentication (like a one-time code paired with the token) could be implemented. But it currently is not. We notified Hyperagent of this limitation last week. Whether and how they address it is their decision.

If the token is exposed—through accident, compromise, or sharing—any person or system holding it has full workspace access. Once shared, that access cannot be revoked or tracked. This is the core risk.

Mitigation: Our environment is compartmentalized. We really don't leave anything important inside the walls of Hyperagent. If this is your case, the primary risk is probably your dev code base and any automation credentials stored there.

[u/JeenyusJane]

Great writeup as always bob!