Agent Interop
In Admin → Agent Interop, you register external agent connections and control which protocols are in use. Delegate work to specialist agents inside Fontana, hand off conversations when the task changes, or federate with external platforms over open protocols (A2A, ACP, ANP, OFP). Every delegation runs with allowlisted origins, bearer authentication, and audit metadata.
In-app orchestration patterns
Section titled “In-app orchestration patterns”Use SubAgent Delegation to isolate deep work in child threads while the parent keeps context lean.
Use Agent Handoff to transfer the root thread to a specialist agent when the task surface changes.
Use Agent Interop with A2A, ACP, ANP, OFP, and other standards to communicate with external agents.
| Pattern | Status | What it does | Configuration |
|---|---|---|---|
| SubAgent delegation | Available | Spawn a child thread for delegated work, then return results to the parent. Isolates deep work while the parent keeps context lean. | subagents on the agent definition in Admin → Agents |
| Agent handoff | Available | Transfer the current conversation to another in-app agent on the same thread. Use when the task surface changes. | handoffAgents on the agent definition in Admin → Agents |
External protocols
Section titled “External protocols”Configure connections in Admin → Agent Interop. Supported and planned federation protocols:
| Protocol | Status | Technical description | Documentation |
|---|---|---|---|
| A2A (Agent2Agent) | Available | JSON-RPC 2.0 over HTTPS for peer-agent task delegation. Outbound: in-app agents delegate tasks to registered connections with allowlisted origins and bearer auth (env or Vault). Inbound: workspace Agent Card at /.well-known/agent-card.json, per-agent cards, and bearer-authenticated JSON-RPC at /api/a2a/json-rpc. | A2A specification |
| ACP (Agent Communication Protocol) | Available | REST-native agent messaging with MIME-typed multipart payloads, session identifiers, and manifest-based discovery. | ACP specification |
| ANP (Agent Network Protocol) | Coming soon | Decentralised peer-to-peer agent networking using W3C Decentralized Identifiers (DIDs) and JSON-LD capability metadata. Complements enterprise A2A when agents must federate across organisational boundaries without a central registry. | ANP repository |
| OFP (Open Floor Protocol) | Coming soon | Linux Foundation standard for multi-party conversational agents: Conversation Envelopes, Assistant Manifests, and Dialog Events. Supports delegation, mediation, and shared floor control across heterogeneous voice and chat agents. | OFP introduction |
Inbound and outbound behaviour
Section titled “Inbound and outbound behaviour”- Outbound delegation - in-app agents send A2A JSON-RPC tasks to registered peer connections with allowlisted origins and bearer authentication
- Inbound discovery - workspace publishes an Agent Card at
/.well-known/agent-card.jsonplus per-agent cards - Inbound API - bearer-authenticated JSON-RPC at
/api/a2a/json-rpcfor inbound task execution - Admin → Agent Interop - connection CRUD, allowlisted HTTPS origins, audit metadata on tool calls
Related documentation
Section titled “Related documentation”- Agents - in-app personas, subagents, and handoff configuration
- Tools and MCP - MCP integrations distinct from peer-agent federation
- Immutable audit trail - delegation and tool-call audit evidence