Set or clear the active session for a provider; the active session is used when a request omits sessionId.
AI agents use session_set_active to create or update resources in LLM CLI Gateway — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your LLM CLI Gateway environment.
The tool modifies session state by setting or clearing an active session, which affects subsequent requests. This is a Write operation because it creates or modifies data (session configuration) reversibly—the active session can be changed again or cleared. It is not Destructive because the previous session is not irreversibly deleted, merely deactivated.
From the tool's definition Tool description states 'Set or clear the active session for a provider', which explicitly indicates modifying state (setting/clearing) rather than querying it. This is a reversible configuration change.
Documented attack patterns abuse exactly the kind of access session_set_active gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and LLM CLI Gateway, and nothing reaches the server without passing your rules. This is the rule we recommend for session_set_active:
{
"version": "1",
"default": "deny",
"tools": {
"session_set_active": {
"limits": [
{
"counter": "session_set_active_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}session_set_active stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
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Set or clear the active session for a provider; the active session is used when a request omits sessionId. It is categorised as a Write tool in the LLM CLI Gateway MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the LLM CLI Gateway MCP server in PolicyLayer and add a rule for session_set_active: 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 LLM CLI Gateway. Nothing to install.
session_set_active 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 session_set_active 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 session_set_active. 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.
session_set_active is provided by the LLM CLI Gateway MCP server (llm-cli-gateway). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from LLM CLI Gateway, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
46 LLM CLI Gateway tools catalogued and risk-classified — across an index of 43,000+ MCP servers.