Create a short-lived MCP session token from an API key. Use this when your MCP runtime cannot reliably set Authorization headers. No authentication required.
Risk signalsHandles credentials or secrets (api_key)
Part of the Fabric Marketplace server.
Free to start. No card required.
AI agents use fabric_login_session to create or modify resources in Fabric Marketplace. Write operations carry medium risk because an autonomous agent could trigger bulk unintended modifications. Rate limits prevent a single agent session from making hundreds of changes in rapid succession. Argument validation ensures the agent passes expected values.
Without a policy, an AI agent could call fabric_login_session repeatedly, creating or modifying resources faster than any human could review. PolicyLayer's rate limiting ensures write operations happen at a controlled pace, and argument validation catches malformed or unexpected inputs before they reach Fabric Marketplace.
Write tools can modify data. A rate limit prevents runaway bulk operations from AI agents.
{
"version": "1",
"default": "deny",
"tools": {
"fabric_login_session": {
"limits": [
{
"counter": "fabric_login_session_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}See the full Fabric Marketplace policy for all 7 tools.
These attack patterns abuse exactly the kind of access fabric_login_session gives an agent. Each links to the full case and the policy that stops it:
Other write tools across the catalogue. The same approach applies to each: rate-limit and validate the arguments.
Create a short-lived MCP session token from an API key. Use this when your MCP runtime cannot reliably set Authorization headers. No authentication required.. It is categorised as a Write tool in the Fabric Marketplace MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Fabric Marketplace MCP server in PolicyLayer and add a rule for fabric_login_session: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Fabric Marketplace. Nothing to install.
fabric_login_session is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the fabric_login_session rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for fabric_login_session. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
fabric_login_session is provided by the Fabric Marketplace MCP server (https://fabric-api-393345198409.us-west1.run.app/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 7 Fabric Marketplace tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.