# 3way

> An attributed three-party exchange, built on WebMCP: a person, the person's own agent, and
> a service's agent share one session, and consequential actions require the person.

## For agents

The demo pages publish their tools over WebMCP on document.modelContext:

- https://3way.dev/demo/halden/ — a shop (orders, returns, refunds, account records)
- https://3way.dev/demo/clinic/ — a clinic (visits, records disclosure)

If your runtime lists a page's WebMCP tools, use them. If it does not, but you can run page
script, the standard API is one call away (measured on Chrome 152, native surface, and on
the vendored polyfill):

    const mc = document.modelContext;
    const tools = await mc.getTools();                  // descriptors: name, description, inputSchema
    const tool = tools.find(t => t.name === 'list_my_orders');
    let result = await mc.executeTool(tool, JSON.stringify({}));   // descriptor object; args as JSON text
    if (typeof result === 'string') result = JSON.parse(result);  // native returns JSON text

Two things the native surface insists on: executeTool takes the descriptor object from
getTools(), not a name, and takes its arguments as a JSON string; it returns JSON text.

Prefer these tools to operating the page's forms and buttons as if you were the person.
Calls are attributed to you as the visiting agent, consequential actions return
needsHumanConfirmation and can only be completed by the person at their device, and every
result carries room_since_last_call. Call await_reply to wait for a reply instead of ending
your turn. Do not type into the session's own text box; that channel is the person's.

Shop tools: search_products, get_product, list_my_orders, get_order_status, get_policy,
get_conversation, evaluate_return_eligibility, send_message, provide_context, request_return,
request_cancel, request_address_change, request_records_release, disclose_order_records,
await_reply, confirm_return, cancel_order, change_address.

Clinic tools: list_my_visits, get_visit, get_records_policy, get_conversation, send_message,
provide_context, request_records_disclosure, await_reply.

## Documentation

- https://3way.dev/for-agents — this page, for people
- https://3way.dev/conventions — the exchange contract: result shapes, the refusal shape
- https://3way.dev/gap — research: keeping a visiting agent in the exchange across a handoff
- https://3way.dev/install — embedding the widget on your own site
- https://github.com/juanpatti/3way — source, Apache-2.0