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, the team behind TeamOffsite. 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.

Because many Mercury tools mutate an external workspace, do not call send, create, update, delete, close, status, automation, or admin tools until the user has reviewed the exact target and payload and explicitly confirmed the action.

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