lean_ctx/tools/registered/
ctx_ledger.rs

1use rmcp::model::Tool;
2use rmcp::ErrorData;
3use serde_json::{json, Map, Value};
4
5use crate::core::context_field::ContextItemId;
6use crate::core::context_overlay::{
7    ContextOverlay, OverlayAuthor, OverlayOp, OverlayScope, OverlayStore,
8};
9use crate::server::tool_trait::{get_str, McpTool, ToolContext, ToolOutput};
10use crate::tool_defs::tool_def;
11
12pub struct CtxLedgerTool;
13
14impl McpTool for CtxLedgerTool {
15    fn name(&self) -> &'static str {
16        "ctx_ledger"
17    }
18
19    fn tool_def(&self) -> Tool {
20        tool_def(
21            "ctx_ledger",
22            "Context ledger ops: status|reset|evict. Manages persistent context pressure.",
23            json!({
24                "type": "object",
25                "properties": {
26                    "action": {
27                        "type": "string",
28                        "enum": ["status", "reset", "evict"],
29                        "description": "Ledger operation: status (show pressure), reset (clear all), evict (remove specific files)"
30                    },
31                    "targets": {
32                        "type": "string",
33                        "description": "Comma-separated file paths to evict (required for 'evict' action)"
34                    }
35                },
36                "required": ["action"]
37            }),
38        )
39    }
40
41    fn handle(
42        &self,
43        args: &Map<String, Value>,
44        ctx: &ToolContext,
45    ) -> Result<ToolOutput, ErrorData> {
46        let action = get_str(args, "action")
47            .ok_or_else(|| ErrorData::invalid_params("action is required", None))?;
48
49        let ledger_arc = ctx
50            .ledger
51            .as_ref()
52            .ok_or_else(|| ErrorData::internal_error("ledger not available", None))?;
53
54        let result = match action.as_str() {
55            "status" => {
56                let ledger = tokio::task::block_in_place(|| ledger_arc.blocking_read());
57                let pressure = ledger.pressure();
58                let top_files: Vec<String> = ledger
59                    .files_by_token_cost()
60                    .iter()
61                    .take(5)
62                    .map(|(path, tokens)| {
63                        format!(
64                            "  {} ({} tok)",
65                            crate::core::protocol::shorten_path(path),
66                            tokens
67                        )
68                    })
69                    .collect();
70
71                let mut lines = vec![
72                    format!(
73                        "Context pressure: {:.0}% ({}/{} tokens)",
74                        pressure.utilization * 100.0,
75                        ledger.total_tokens_sent,
76                        ledger.window_size,
77                    ),
78                    format!("Entries: {}", ledger.entries.len()),
79                    format!("Recommendation: {:?}", pressure.recommendation),
80                ];
81                if !top_files.is_empty() {
82                    lines.push("Top files by cost:".to_string());
83                    lines.extend(top_files);
84                }
85                lines.join("\n")
86            }
87
88            "reset" => {
89                let mut ledger = tokio::task::block_in_place(|| ledger_arc.blocking_write());
90                let prev_entries = ledger.entries.len();
91                let prev_tokens = ledger.total_tokens_sent;
92                ledger.reset();
93                ledger.save();
94                format!(
95                    "Ledger reset. Removed {prev_entries} entries, freed {prev_tokens} tracked tokens. Pressure: 0%."
96                )
97            }
98
99            "evict" => {
100                let targets_str = get_str(args, "targets").ok_or_else(|| {
101                    ErrorData::invalid_params(
102                        "targets is required for evict action (comma-separated paths)",
103                        None,
104                    )
105                })?;
106
107                let targets: Vec<&str> = targets_str.split(',').map(str::trim).collect();
108                if targets.is_empty() {
109                    return Ok(ToolOutput::simple(
110                        "No targets specified for eviction.".to_string(),
111                    ));
112                }
113
114                let mut ledger = tokio::task::block_in_place(|| ledger_arc.blocking_write());
115                let removed = ledger.evict_paths(&targets);
116
117                // Add exclude overlays to prevent re-accumulation
118                let root = if ctx.project_root.is_empty() {
119                    "."
120                } else {
121                    &ctx.project_root
122                };
123                let mut overlays = OverlayStore::load_project(&std::path::PathBuf::from(root));
124                for target in &targets {
125                    let item_id = ContextItemId::from_file(target);
126                    let overlay = ContextOverlay::new(
127                        item_id,
128                        OverlayOp::Exclude {
129                            reason: "evicted by ctx_ledger".into(),
130                        },
131                        OverlayScope::Session,
132                        String::new(),
133                        OverlayAuthor::Policy("ctx_ledger_evict".into()),
134                    );
135                    overlays.add(overlay);
136                }
137                let _ = overlays.save_project(&std::path::PathBuf::from(root));
138
139                ledger.save();
140
141                let pressure = ledger.pressure();
142                format!(
143                    "Evicted {removed}/{} target(s). Pressure now: {:.0}%. Files excluded from re-accumulation until session reset.",
144                    targets.len(),
145                    pressure.utilization * 100.0,
146                )
147            }
148
149            _ => "Unknown action. Use: status, reset, evict".to_string(),
150        };
151
152        let changed = action != "status";
153        Ok(ToolOutput {
154            text: result,
155            original_tokens: 0,
156            saved_tokens: 0,
157            mode: Some(action),
158            path: None,
159            changed,
160        })
161    }
162}
lean_ctx/tools/registered/ctx_ledger.rs

lean_ctx/tools/registered/
ctx_ledger.rs
