One-off experiment
Atlas via MCP
A minimal Stripe-Atlas-style formation flow exposed to AI agents over MCP — built to answer one question: when an agentic flow needs something as sensitive as an SSN, does it have to become a string of digits typed into the chat?
An MCP tool result isn’t limited to text. It can include a resourcecontent block — a self-contained, distinctly-branded UI that a capable host renders inline, separate from the model’s own words. Here, calling start_company_formationreturns exactly that: a green “Atlas Verify” widget, visually nothing like the surrounding chat, whose form posts the SSN straight to its own endpoint. The agent that triggered it never sees the number — it only ever gets back a masked reference once verification finishes.
Connect a real agent
This is a running server, not a mock
Point any MCP-capable agent at the endpoint below and ask it to start a formation. It gets exactly what the panel below shows — a real tool result carrying a real embedded widget.
claude mcp add --transport http atlas-demo https://one-off.dev/api/atlas/mcp
claude.ai / desktop app — Settings → Connectors → Add custom connector
https://one-off.dev/api/atlas/mcpTwo tools: start_company_formation and check_verification_status. Demo data only — nothing is persisted past ~15 minutes, and no SSN digits are ever logged or stored.
Watch the protocol in action
Run the real handshake
This panel speaks to the real endpoint at /api/atlas/mcp — no mocks. Start a formation, then fill out the green Atlas Verify widget that comes back with any 9 digits (this is a demo; nothing is checked against a real SSN or stored anywhere). Watch the JSON-RPC transcript: the number never appears in it.