# set_role

Set active PostgreSQL role/user for the session (SET ROLE) or reset to default (RESET ROLE)

Agent View of the PolicyLayer registry record for `set_role`. HTML page: https://policylayer.com/tools/allensandiego-postgres-mcp-server/set-role

## Facts

- Tool: `set_role`
- Server: Postgres (`@allensandiego/postgres-mcp-server`) — https://policylayer.com/tools/allensandiego-postgres-mcp-server.md
- Install: `npx -y @allensandiego/postgres-mcp-server`
- Homepage: https://www.npmjs.com/package/@allensandiego/postgres-mcp-server
- Risk category: Write (Medium risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 1 (1 required)
- Recommended policy verdict: Rate-limited

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `role` | string | yes | Role or username to set (e.g. 'analyst', 'app_user', or 'NONE' / 'RESET' to restore default) |

Parameters from the server's own tool schema.

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "set_role",
    "arguments": {
      "role": "<role>"
    }
  }
}
```

## Why set_role is rated Medium

An AI agent can call set_role faster than any human can review: one bad instruction and it creates or modifies resources in Postgres by the hundred, each call as confident as the last.

## Use case

AI agents use set_role to create or update resources in Postgres, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Postgres environment.

## Recommended policy (PolicyLayer)

Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Postgres:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "set_role": {
      "limits": [
        {
          "counter": "set_role_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Postgres (7)

- `run_query` — Execute — https://policylayer.com/tools/allensandiego-postgres-mcp-server/run-query.md
- `run_write_query` — Execute — https://policylayer.com/tools/allensandiego-postgres-mcp-server/run-write-query.md
- `describe_table` — Read — https://policylayer.com/tools/allensandiego-postgres-mcp-server/describe-table.md
- `list_databases` — Read — https://policylayer.com/tools/allensandiego-postgres-mcp-server/list-databases.md
- `list_permissions` — Read — https://policylayer.com/tools/allensandiego-postgres-mcp-server/list-permissions.md
- `list_roles` — Read — https://policylayer.com/tools/allensandiego-postgres-mcp-server/list-roles.md
- `list_tables` — Read — https://policylayer.com/tools/allensandiego-postgres-mcp-server/list-tables.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=allensandiego-postgres-mcp-server · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/allensandiego-postgres-mcp-server