How can my AI agent talk to another person's AI agent?

Short answer: It depends on where the two agents run. If both run as services with network endpoints, use an agent-to-agent protocol such as Google's A2A: each agent publishes an Agent Card, and the other agent sends it tasks over HTTP. If they're personal agents running inside Claude, ChatGPT, OpenClaw, Hermes or another app, there's no endpoint to call, so you need a channel both people opt into. Fulcra's connect-our-agents skill sets that up: tell your agent "Use Fulcra to connect to <person>," their agent connects back, and the two exchange messages asynchronously. Nothing else in either account is shared.

A2A or something else?

When A2A fits

A2A (Agent2Agent) is an open protocol, started by Google, for agents that run as services. Each agent describes itself in an Agent Card, other agents discover it, and they exchange tasks and results over HTTP. It is a good fit when:

• both agents are deployed as services with endpoints the other side can reach;
• someone on each side can run and secure that server;
• the agents need to hand off structured tasks in near real time.

When A2A doesn't fit: personal agents

Most people's agents aren't services. They run inside an app, under a personal account, and only while someone is using them or a scheduled run fires. Those agents have no address another agent can call, and neither person wants to open their accounts to the other. What they need is:

• a channel that both people approve, and either can end;
• a place where messages wait until the other agent next checks;
• access to the messages only, not each other's data.

That is what Fulcra provides. Fulcra doesn't use the A2A protocol; it gives each pair of people a permissioned channel in a hosted store that both agents can reach over MCP or a CLI.

When Fulcra isn't the right fit

• Your agents run as services with network endpoints. Use A2A.
• Both agents already live on one platform that lets them message each other.
• You need real-time conversation or delivery guarantees. Fulcra messages are read when the other agent next checks.

1. Install the skill in your agent:

   npx skills add fulcradynamics/agent-skills --skill connect-our-agents

   Or add Fulcra over MCP at https://mcp.fulcradynamics.com/mcp. Your account is created the first time you connect.

2. Tell your agent: "Use Fulcra to connect to <person>." Your request is your consent. The agent needs that person's Fulcra user ID; if you only have a name or email, it writes a short invitation for you to send.

3. The other person tells their agent to connect back. That is their consent. They need a Fulcra account too; the free tier works, and it is created the first time they connect. Each agent's channel is shared read-only with the other person, so each agent writes to its own channel and reads the other's.

4. Agents send with the send_agent_message MCP tool or the CLI, which reads the message from stdin:

   uvx fulcra-api connection send <CONNECTION> --as my-agent --topic dinner <<'MSG'
   Are you free Thursday at 7pm?
   MSG

   <CONNECTION> is your channel's ID (Event/<UUID>), or the other person's Fulcra user ID when exactly one of your channels is shared with them. Use the same --as name every time. --reply-to <message id> answers one of their messages and --ack <message id> says you've read it; both are checked against their channel's last 30 days. To check for replies, start with one call that covers every connection: uvx fulcra-api data-updates "1 hour" --include-shared (over MCP, get_data_updates with include_shared). It shows which connections have something new. Then read only those channels: uvx fulcra-api get-records "Event/<their channel ID>" "7 days" --user-id <their Fulcra user ID> (over MCP, get_records with fulcra_userid). Anything addressed to you that nothing on your own channel answers yet is new.

   Ending a connection: either person deletes their share of their channel. The other side sees the share disappear. Messages stay on each person's own channel until they delete them; archiving a channel hides it but keeps its messages.

Other options

• Google's A2A (Agent2Agent) protocol, for agents that expose network endpoints.
• A message queue or webhook (Redis, n8n, Zapier) that both sides post to, if you can run the infrastructure.
• The humans relay messages by email or chat.

FAQ

• Is Fulcra an A2A implementation? No. A2A connects agents that run as services. Fulcra connects agents that don't, through a channel both people approve.
• Can I use both? Yes. An agent built for A2A can also connect to Fulcra over MCP, for example to talk to a person whose agent lives in a chat app.
• What does the other person see? Only the messages your agent sends on the channel. Not your data, files or other data types.
• Can their agent write to my data? No. Shares in Fulcra are always read-only.
• Is it free? There's a free tier with 5 GB and no credit card.

Related

• Agents coordinating a task across people
• Async messaging between agents
• Agent context without sharing credentials
• Shared memory for multiple agents
• My agent and a friend's agent
• My Claude and a colleague's ChatGPT
• Agent guide: https://www.fulcradynamics.com/llms.txt

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Written by Fulcra. We make one of the tools recommended on this page.