Registry — 20 transports · verified 2026-09-25
Transports
The pipe, not the endpoint. A transport is the channel or wire format an agent's bytes travel over — MCP and A2A between software, Slack and email between people, SSH and mesh VPNs into machines, PSTN and WebRTC for voice. Integrations tell you what an agent connects to; transports tell you how the conversation physically moves.
Agent wire protocols — Wire formats between agents, hosts, and tool servers
A2A (Agent2Agent)
Cross-vendor agent wire: Agent Cards for discovery, task lifecycle and streaming updates. Google-originated, now Linux Foundation.
05 agents →ACP
Two lineages share the acronym: Zed's Agent Client Protocol (editor↔agent, JSON-RPC — how JetBrains/VS Code embed terminal agents) and IBM's earlier Agent Communication Protocol, now folded into A2A.
06 agents →AG-UI
CopilotKit's event protocol between an agent backend and a frontend — streaming state, tool calls, and human-in-the-loop checkpoints.
—AGNTCY / SLIM
Cisco-originated 'Internet of Agents' stack — agent directory plus the SLIM secure messaging fabric and identity badges.
01 agents →AITP
NEAR's Agent Interaction & Transaction Protocol — capability negotiation and payments between agents, still early.
—ANP (Agent Network Protocol)
Decentralized agent web — DID-based identity, capability description, and peer-to-peer messaging with no central directory.
01 agents →MCP (Model Context Protocol)
JSON-RPC tool and context wire between an agent runtime and tool servers — stdio or streamable HTTP.
35 agents →Messaging channels — Human-facing chat and mail channels agents speak
Discord
Gateway websocket plus slash commands — community servers double as agent control rooms.
05 agents →Email (SMTP/IMAP)
The oldest interoperable messaging transport — agents get an address, parse threads, and reply over SMTP/IMAP.
15 agents →iMessage
macOS-only bridges drive Messages.app — no official API, so agents piggyback on a logged-in Mac.
01 agents →Signal
signal-cli / linked-device bridges — private-channel agents where the audience is one person.
01 agents →Slack
The default enterprise channel — agents listen, reply, and post via Bolt apps or incoming webhooks.
20 agents →Telegram
Bot API long-polling or webhooks — the most common channel for self-hosted personal agents.
06 agents →Business Cloud API or bridged sessions — the consumer channel with the widest reach.
05 agents →Remote access & reachability — How the outside world reaches a local agent
HTTPS tunnels
Cloudflare Tunnel, ngrok, Tailscale Funnel — give a localhost agent a public URL for inbound webhooks and remote control.
01 agents →Mesh VPN (Tailscale-class)
WireGuard overlays like Tailscale, ZeroTier, NetBird — a self-hosted agent stays reachable across devices without ever touching the public internet.
04 agents →SSH
The default pipe into a remote machine — cloud agents provision SSH-reachable workspaces, and every terminal agent inherits it wherever it runs.
03 agents →Webhooks
Inbound HTTP callbacks — how external systems wake an agent up rather than the agent polling.
04 agents →Realtime media — Low-latency voice and media pipes
Frequently asked
What counts as a transport?
The pipe, not the endpoint. A transport is the channel or wire format an agent's bytes travel over — MCP and A2A between software, Slack and email between people, SSH and mesh VPNs into machines, PSTN and WebRTC for voice. Integrations tell you what an agent connects to; transports tell you how the conversation physically moves.
Aren't Slack and Gmail already listed under integrations?
Yes — a channel can be both. As an integration, Slack is a target the agent connects to. As a transport, the Slack socket is how a human reaches the agent and how its replies get back out. The same channel appears in both registries when it plays both roles.
Why do wire protocols matter more than model choice?
Protocols outlive vendors. An agent that speaks MCP can use every MCP server ever written; one that speaks A2A can be discovered and tasked by any compliant orchestrator. The wire format determines who else the agent can talk to — swap the model and the transports still hold.
How are transports assigned to systems?
Only transports verifiable from each system's documented feature set are tagged — an MCP client or server mode, a documented Slack/Telegram channel, SSH into a provisioned workspace, telephony for voice agents. Tags are re-checked when the catalog is regenerated.