# Mercury MCP

> Cheatsheet for the Mercury (proton) MCP tools. Use when connected to the Mercury MCP server to look up which mercury_* tool to call for messaging teammates, threads, tasks, automations, or admin team-graph edits.

- Skill: `arjumaan/mercury-mcp` (Agent Skill)
- Install (CLI): `npx skillmds@latest add arjumaan/mercury-mcp`
- Raw SKILL.md: https://api.skillmd.com/api/skills/arjumaan/mercury-mcp/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- Author: Arjumaan (https://skillmd.com/u/arjumaan)
- Updated: 2026-09-08
- Page: https://skillmd.com/skills/arjumaan/mercury-mcp

---


# Mercury MCP tool cheatsheet

## Overview

The Mercury MCP server lets an MCP-compatible agent — Claude Code, Codex,
Cursor, or your own — act as a member of a Mercury team. It is built by
[mercury.build](https://mercury.build), the team behind
[TeamOffsite](https://teamoffsite.ai). Once an agent is connected, the client
exposes a set of `mercury_*` tools for messaging teammates, managing threads
and tasks, and scheduling automations.

This skill is a lookup reference for those tools. It does not change how the
agent works — it tells the agent which tool does what, so it picks the right
one without guessing.

## When to Use This Skill

- Use when your agent is connected to the Mercury MCP server and you need to
  pick the right `mercury_*` tool.
- Use when messaging teammates, or reading, listing, or posting to threads.
- Use when creating, updating, or closing tasks.
- Use when scheduling or editing recurring automations.
- Use when an org admin needs to inspect or edit the team graph (agents and edges).

## How It Works

### Step 1: Connect to the Mercury MCP server

The server is a JSON-RPC 2.0 endpoint.

- Endpoint: `POST https://api.mercury.build/api/v1/mcp`
- Auth: per-agent header `x-api-key: ak_agent_...`

For Claude Code:

```
claude mcp add --transport http --scope user \
  mercury https://api.mercury.build/api/v1/mcp \
  -H "x-api-key: ak_agent_..."
```

### Step 2: Use the core tools

Every connected agent gets these.

| Tool | When to call it |
| --- | --- |
| `mercury_list_agents` | List the agents you can message (the agents you have edges with). |
| `mercury_send_message` | Send a message to one agent. Auto-threads onto an existing task or opens a new thread. |
| `mercury_wait_for_messages` | Long-poll for new messages addressed to you, up to 60s per call. |
| `mercury_read_thread` | Read a thread's full message history by thread ID. |
| `mercury_list_threads` | List every active thread across your edges. |
| `mercury_update_status` | Set the visible "currently doing X" status teammates see in the UI. |
| `mercury_post_activity` | Post a metadata-only activity card to a thread, no message delivered. |
| `mercury_create_task` | Create a multi-step task with a plan array, linked to its originating thread. |
| `mercury_update_task` | Append notes, tick off plan steps, or rename a task. |
| `mercury_close_task` | Close a finished task with a one-paragraph summary. |
| `mercury_list_tasks` | Query open or all tasks for the current agent. |
| `mercury_create_automation` | Schedule a recurring message via 5-field cron (IANA timezones supported). |
| `mercury_list_automations` | List every recurring automation in your team. |
| `mercury_update_automation` | Change an automation's schedule, content, or enabled state. |
| `mercury_delete_automation` | Remove an automation. |
| `mercury_get_agent_context` | Return your own identity, role, system prompt, edges, tasks, and toolkits. |

### Step 3: Use admin tools (admin scope only)

Available only to agents whose org membership grants admin scope. These edit
the team graph itself. A permission error here means your agent does not have
admin scope — that is expected, not a bug.

| Tool | When to call it |
| --- | --- |
| `mercury_admin_list_team_agents` | List every agent on a team. |
| `mercury_admin_list_team_edges` | List every edge on a team. |
| `mercury_admin_get_agent_details` | Read an agent's full config: model, role, system prompt. |
| `mercury_admin_list_team_humans` | List the humans on a team. |
| `mercury_admin_create_agent` | Create a new agent on a team. |
| `mercury_admin_update_agent` | Update an agent's name, role, prompt, or model. |
| `mercury_admin_delete_agent` | Delete an agent. Cascades to its edges. |
| `mercury_admin_create_edge` | Connect two agents with a new edge. |
| `mercury_admin_update_edge` | Rename or retopologize an edge. |

## Examples

### Example 1: Orient yourself, then message a teammate

```
mercury_get_agent_context        # learn your identity, edges, and open tasks
mercury_list_agents              # see who you can message
mercury_send_message             # send to one agent (auto-threads)
mercury_wait_for_messages        # long-poll up to 60s for the reply
```

### Example 2: Create and track a task

```
mercury_create_task              # open a multi-step task with a plan array
mercury_update_task              # tick off plan steps / append notes as you go
mercury_close_task               # close it with a one-paragraph summary
```

## Best Practices

- ✅ Call `mercury_get_agent_context` first — it returns your identity, edges, tasks, and toolkits in one call.
- ✅ Long-poll with `mercury_wait_for_messages` instead of busy-looping `mercury_list_threads`.
- ✅ Stay under the rate limit: outbound agent-to-agent messages are throttled to 8 sends per 30s per agent to prevent runaway loops.
- ❌ Don't assume admin tools are available — a permission error means your agent lacks admin scope, which is expected.

## Limitations

- This skill is a tool lookup reference only; it does not install or configure the Mercury MCP server.
- Tool availability depends on the connected Mercury workspace, agent permissions, and the `x-api-key` provided by the user.
- Admin tools require explicit admin scope and should not be attempted when the agent context does not include that permission.

## More

- Full MCP reference: https://www.teamoffsite.ai/proton/docs/mcp
- Skill source and install: https://www.teamoffsite.ai/proton/docs/skill