feat: thunderbolt-stdio-bridge — bridge local stdio ACP agents and MCP servers#989
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Updated Thu, 18 Jun 2026 22:28:03 GMT · run #1963 |
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…e relay at startup
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| 'agent) is now reachable by other hosts on the network, not just this\n' + | ||
| 'machine. Keep the default 127.0.0.1 unless you really need remote access.\n', | ||
| ) | ||
| } |
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Bridge bind warning too narrow
Low Severity
emitInsecureFlagWarnings treats only 127.0.0.1, localhost, and ::1 as loopback. Other valid loopback binds (rest of 127.0.0.0/8, *.localhost) still get the “reachable by other hosts on the network” warning even though they remain local-only.
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Note
Medium Risk
Changes ACP/MCP transport routing for loopback targets (intentional proxy skip on web) and ships a new local bridge that fronts privileged agents; mitigated by origin checks, tests, and unchanged non-loopback proxy behavior.
Overview
Introduces
thunderbolt-stdio-bridge, a local CLI that relays stdio agents to Thunderbolt over--mode acp(localhost WebSocket) or--mode mcp(Streamable HTTP at/mcp, optional cloudflared tunnel with mandatory bearer). The app is updated so those URLs actually work from the web app, not only desktop.Loopback bypass: New
isLoopbackUrl/isLoopbackHostdetection drives two carve-outs—remote ACP WebSockets and MCP HTTP now use a native connect (no universal cloud proxy) when the target is localhost /127.0.0.0/8/::1/*.localhost, including in the browser. Non-loopback remote agents still proxy as before.Settings UX: Agent catalog cards get Connect via bridge (install +
npx thunderbolt-stdio-bridge --mode acp -- …commands from registry distribution), CopyableCommand, and handoff to Add Custom Agent. Loopback URLs in that dialog show a local network permission hint.The bridge package includes Origin allowlisting, PII-safe logging, child supervision, and broad unit/integration tests.
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