Custo Claude Code de uma sessão específica (ou da sessão ativa auto-deduzida pelo arquivo JSONL mais recente com mtime < 30min). Retorna shape canônico + session_id, started_at, last_activity_at, source_file. Triggers:
AI agents call cost-session to retrieve information from Kit without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
The tool reads and returns cost/session information from a JSONL file. It queries session data (auto-deduced from the most recent JSONL file) and returns structured metadata. No side effects or mutations are described.
From the tool's definition 'Custo Claude Code de uma sessão específica' — retrieves cost data for a specific session; 'Retorna shape canônico + session_id, started_at, last_activity_at, source_file' — returns read-only session metadata
Attacks that exploit this kind of access
Custo Claude Code de uma sessão específica (ou da sessão ativa auto-deduzida pelo arquivo JSONL mais recente com mtime < 30min). Retorna shape canônico + session_id, started_at, last_activity_at, source_file. Triggers:. It is categorised as a Read tool in the Kit MCP Server, which means it retrieves data without modifying state.
Register the Kit MCP server in PolicyLayer and add a rule for cost-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 Kit. Nothing to install.
cost-session is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the cost-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 cost-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.
cost-session is provided by the Kit MCP server (luanpdd/kit-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
cost-session is one line of Kit's registry record.
The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.
Teams ship this data inside their own products. See what a licence covers →