API Keys
Create and manage Runstack API keys for authenticating with the MCP server. Understand per-plan usage limits.
API keys authenticate your requests to the Runstack MCP server at /mcp. Each key belongs to a specific plan tier that controls how many tool executions it allows.
Plan limits
| Plan | Executions per key | Notes |
|---|---|---|
| FREE | 50 | Default for new keys |
| STARTER | Unlimited | Priority email support |
| PRO | Unlimited | Private endpoints, enterprise analytics |
A tool execution is counted each time execute_tool is called through the MCP server. search_tools, check_authentication, and initiate_connection do not count toward the limit.
Creating a key
- Go to Settings in the Runstack sidebar
- Enter a name for the key (used only for your reference — e.g.
Claude Desktop) - Select the plan tier
- Click Create Key
- Copy the key now — the full value is shown only once
Keys are prefixed with rsk_ followed by 64 hex characters.
Key security
- Keys are stored as SHA-256 hashes in the database — not in plain text
- Only the first 12 characters (
keyPrefix) are stored for display - If a key is compromised, delete it immediately from Settings and create a new one
- Never commit keys to source control
Usage tracking
Each key tracks:
- Usage count — total calls to
execute_tool - Usage limit — cap based on plan (null = unlimited)
- Last used — timestamp of most recent execution
The Settings page shows a usage bar for each key. When usage reaches 80% of the limit the bar turns yellow; at 100% it turns red and the key is blocked until you upgrade or delete and recreate it.
Deleting a key
Click the trash icon next to any key in Settings. Deletion is immediate and permanent — any client using that key will receive a 401 Unauthorized response on its next request.
Multiple keys
You can create as many keys as you need. Common patterns:
- One key per MCP client (Claude Desktop, Cursor, custom scripts)
- One key per environment (development, production)
- Separate keys for different team members