Introduction
Tier Two sits between your agents and the systems they call. Every tool call gets a policy decision and a record.
The shape of it
Tier Two is a hosted MCP server at https://trytiertwo.com/mcp. Your agent connects to it the way it connects to any other MCP server; on its first tool call a browser window asks you to sign in. Nothing is installed on your machine, and no API key is pasted anywhere.
Behind that one endpoint sit your connections: the systems your workspace has decided agents may reach. Each connection offers tools, and each tool has a mode:
| Mode | What the agent sees | What happens |
|---|---|---|
| Allow | The tool, normally | The call runs and is recorded. |
| Ask | The tool, with a note that it pauses | The call is held until a person approves, then completes on its own. |
| Block | Nothing: the tool is hidden | A call to it anyway is refused and recorded. |
Eight words, one meaning each
- Workspace: your organization. The tenant everything belongs to.
- Connection: one system agents may reach (an MCP server plus its credentials and modes).
- Tool: one callable action on a connection, named
<connection>__<tool>to the agent. - Agent: a client that signed in: Claude Code on a laptop, Cursor, a script.
- Person: a member of the workspace. An agent acts as exactly one.
- Approval: a decision on a paused call: once, or always for that person.
- Activity: the ledger of what happened, refusals included.
- Device: optional, and only if you install the Client: the machine a call came from.
Start here
Two commands and two clicks, in either order:
npx -y tiertwoRegisters the endpoint in every MCP host on the machine, finds the systems your agents already use, and opens the browser to sign in.
Then add your first connection from the catalog, keep the Recommended posture (reads run, writes wait), and ask your agent for a read.