Constant SCHEMA_V7 

pub const SCHEMA_V7: &str = "
    CREATE TABLE IF NOT EXISTS mcp_tool_calls (
        id          INTEGER PRIMARY KEY AUTOINCREMENT,
        ts_ms       INTEGER NOT NULL,
        request_id  TEXT NOT NULL,
        session_id  TEXT NOT NULL,
        consumer    TEXT NOT NULL,
        tool_name   TEXT NOT NULL,
        allowed     INTEGER NOT NULL,
        duration_ms REAL NOT NULL,
        error_code  TEXT,
        status      TEXT NOT NULL
    );
    CREATE INDEX IF NOT EXISTS idx_mcp_tool_calls_session ON mcp_tool_calls(session_id);
    CREATE INDEX IF NOT EXISTS idx_mcp_tool_calls_consumer ON mcp_tool_calls(consumer);
";

Schema v7 (DW-087): the mcp_tool_calls table. One row per MCP tool call proxied through the gateway, carrying the session correlation id, the authenticated consumer, the tool name, the authorization outcome (allowed), the call duration, an optional error code, and a status string (success, error, or denied). The admin /mcp/calls endpoint reads these rows; the session and consumer indexes support per-session and per-consumer drill-down.