lean_ctx/tools/registered/
ctx_cost.rs

1use rmcp::ErrorData;
2use rmcp::model::Tool;
3use serde_json::{Map, Value, json};
4
5use crate::server::tool_trait::{McpTool, ToolContext, ToolOutput, get_str, get_usize};
6use crate::tool_defs::tool_def;
7
8pub struct CtxCostTool;
9
10impl McpTool for CtxCostTool {
11    fn name(&self) -> &'static str {
12        "ctx_cost"
13    }
14
15    fn tool_def(&self) -> Tool {
16        tool_def(
17            "ctx_cost",
18            "Cost attribution — track tokens and cost per agent/tool call. Local-first, no external billing.\n\
19            Actions: report (summary), agent (per-agent), tools (per-tool), json (machine), status (live), reset (zero).\n\
20            WORKFLOW: call report to find top cost drivers, then agent/tools for detail.",
21            json!({
22                "type": "object",
23                "properties": {
24                    "action": {
25                        "type": "string",
26                        "enum": ["report", "agent", "tools", "json", "reset", "status"],
27                        "description": "report|agent|tools|json|reset|status"
28                    },
29                    "agent_id": {
30                        "type": "string",
31                        "description": "Agent ID"
32                    },
33                    "limit": {
34                        "type": "integer",
35                        "description": "Max rows"
36                    }
37                }
38            }),
39        )
40    }
41
42    fn handle(
43        &self,
44        args: &Map<String, Value>,
45        _ctx: &ToolContext,
46    ) -> Result<ToolOutput, ErrorData> {
47        let action = get_str(args, "action").unwrap_or_else(|| "report".to_string());
48        let agent_id = get_str(args, "agent_id");
49        let limit = get_usize(args, "limit").map(|n| n.min(100_000));
50
51        let result = crate::tools::ctx_cost::handle(&action, agent_id.as_deref(), limit);
52
53        Ok(ToolOutput {
54            text: result,
55            original_tokens: 0,
56            saved_tokens: 0,
57            mode: Some(action),
58            path: None,
59            changed: false,
60            shell_outcome: None,
61        })
62    }
63}
lean_ctx/tools/registered/ctx_cost.rs

lean_ctx/tools/registered/
ctx_cost.rs
