lean_ctx/tools/registered/
ctx_fill.rs1use rmcp::model::Tool;
2use rmcp::ErrorData;
3use serde_json::{json, Map, Value};
4
5use crate::server::tool_trait::{
6 get_int, get_str, get_str_array, McpTool, ToolContext, ToolOutput,
7};
8use crate::tool_defs::tool_def;
9
10pub struct CtxFillTool;
11
12impl McpTool for CtxFillTool {
13 fn name(&self) -> &'static str {
14 "ctx_fill"
15 }
16
17 fn tool_def(&self) -> Tool {
18 tool_def(
19 "ctx_fill",
20 "Budget-aware context fill — auto-selects compression per file within token limit.",
21 json!({
22 "type": "object",
23 "properties": {
24 "paths": {
25 "type": "array",
26 "items": { "type": "string" },
27 "description": "File paths to consider"
28 },
29 "budget": {
30 "type": "integer",
31 "description": "Maximum token budget to fill"
32 },
33 "task": {
34 "type": "string",
35 "description": "Optional task for POP intent-driven pruning"
36 }
37 },
38 "required": ["paths", "budget"]
39 }),
40 )
41 }
42
43 fn handle(
44 &self,
45 args: &Map<String, Value>,
46 ctx: &ToolContext,
47 ) -> Result<ToolOutput, ErrorData> {
48 let raw_paths = get_str_array(args, "paths")
49 .ok_or_else(|| ErrorData::invalid_params("paths array is required", None))?;
50 let budget = get_int(args, "budget")
51 .ok_or_else(|| ErrorData::invalid_params("budget is required", None))?
52 as usize;
53 let task = get_str(args, "task");
54
55 tokio::task::block_in_place(|| {
56 let session_lock = ctx
57 .session
58 .as_ref()
59 .ok_or_else(|| ErrorData::internal_error("session not available", None))?;
60 let cache_lock = ctx
61 .cache
62 .as_ref()
63 .ok_or_else(|| ErrorData::internal_error("cache not available", None))?;
64
65 let mut paths = Vec::with_capacity(raw_paths.len());
66 {
67 let session = session_lock.blocking_read();
68 for p in &raw_paths {
69 match super::resolve_path_sync(&session, p) {
70 Ok(resolved) => paths.push(resolved),
71 Err(e) => {
72 return Err(ErrorData::invalid_params(e, None));
73 }
74 }
75 }
76 }
77
78 let mut cache = cache_lock.blocking_write();
79 let output = crate::tools::ctx_fill::handle(
80 &mut cache,
81 &paths,
82 budget,
83 ctx.crp_mode,
84 task.as_deref(),
85 );
86 drop(cache);
87
88 Ok(ToolOutput {
89 text: output,
90 original_tokens: 0,
91 saved_tokens: 0,
92 mode: Some(format!("budget:{budget}")),
93 path: None,
94 changed: false,
95 })
96 })
97 }
98}