MCP tools and resources

Not live yet. The execution server at https://mcp.usehence.com/mcp is still being built, so none of the calls below answer today. This page is the published contract they are being built against; the per-call schemas here are generated from the server once it ships, and this page is replaced by that generated output.

Everything is reached through one server, over Streamable HTTP, with OAuth 2.1. Adding the server is covered on the Connect pages.

Resources

Resource	What it is
`capabilities`	The generated manifest: every errand’s intents, admission conditions, required inputs, published ceiling, blockers and instruments, jurisdiction and freshness. Deterministically ordered and cacheable.
`task://…/receipt`	The receipt for a task or one of its steps — what was requested, of whom, on what date, by what route, what confirmation to expect, and the proof of delivery.
`ui://hence/task-card`	An inline card: timeline, links to the screenshots taken, the pending question, approve or decline, receipt. Every card has a text fallback, so a host that cannot render it loses nothing.

Tools

The errand loop

Tool	What it does
`admit`	Runs an errand’s gate against the facts you have. Returns admitted with the inputs still required, or refused with the clause that fired. Call it before promising anything.
`start_task`	Delegates an errand with the facts gathered so far. Returns a durable task id and the first status. The user’s Hence profile is read on our side, never through the host.
`get_task`	Current state, pending input requests, latest update, screenshot references. The baseline path for a host without the tasks extension: poll it.
`answer_task`	Delivers the user’s answer or approval to a pending request. Idempotent on the request id — a duplicate or stale answer is ignored rather than applied twice.
`cancel_task`	Stops a run. Cooperative: it stops at the next safe point.
`list_tasks`	The user’s open tasks. Also the verification call on every Connect page — an empty list is a healthy connection.

Events and watches

Tool	What it does
`poll_events`	Everything since a cursor — a task completed, input needed, a watch fired — each with a text summary, a deep link and a hint for when to check again. This is how a host’s scheduler reaches a user who has closed the conversation.
`create_watch`, `list_watches`, `cancel_watch`	A standing instruction with a kind and parameters. Hence evaluates it on its own schedule and writes an event when it fires. One watch kind exists in the first wave: a new or increased recurring charge.

Two ways to run the same errand

Plain tools. Any host that can call a remote MCP tool can run every errand: start_task, poll get_task, relay each pending question in your own voice, return the answer with answer_task. Results carry references to the screenshots, not the image bytes: a screenshot of a signed-in page stays on our side, and the structured receipt is the receipt. Nothing an errand needs is reserved for richer hosts. Extensions. A host that declares them gets the errand as a durable task handle with input_required, elicitation for questions and approvals — form mode for data points and two-value answers, URL mode for anything sensitive — and the task card as an inline view.

Refusals you should expect to handle

Not admissible. admit refuses with the condition that fired. Show it; it is information for the user, not an error.
Not enabled for this account. Every tool refuses cleanly while access is off. The connection is healthy; do not re-run the OAuth flow, and do not retry in a loop.
Ceiling reached. An errand that hits its published ceiling returns READY with the remaining action named. That is a successful result, not a failure.

Start here

Connect

How tasks work

What Hence can do

Trust and control

Reference

Changelog

MCP tools and resources

Resources

Tools

The errand loop

Events and watches

Two ways to run the same errand

Refusals you should expect to handle

​Resources

​Tools

​The errand loop

​Events and watches

​Two ways to run the same errand

​Refusals you should expect to handle

Resources

Tools

The errand loop

Events and watches

Two ways to run the same errand

Refusals you should expect to handle