lean_ctx/proxy/
anthropic.rs1use axum::{
2 body::Body,
3 extract::State,
4 http::{Request, StatusCode},
5 response::Response,
6};
7use serde_json::Value;
8
9use super::compress::compress_tool_result;
10use super::forward;
11use super::ProxyState;
12
13pub async fn handler(
14 State(state): State<ProxyState>,
15 req: Request<Body>,
16) -> Result<Response, StatusCode> {
17 let upstream = state.anthropic_upstream.clone();
18 forward::forward_request(
19 State(state),
20 req,
21 &upstream,
22 "/v1/messages",
23 compress_request_body,
24 "Anthropic",
25 &[],
26 )
27 .await
28}
29
30fn compress_request_body(body: &[u8]) -> (Vec<u8>, usize, usize) {
31 let original_size = body.len();
32
33 let parsed: Value = match serde_json::from_slice(body) {
34 Ok(v) => v,
35 Err(_) => return (body.to_vec(), original_size, original_size),
36 };
37
38 let mut doc = parsed;
39 let mut modified = false;
40
41 if let Some(messages) = doc.get_mut("messages").and_then(|m| m.as_array_mut()) {
42 for msg in messages.iter_mut() {
43 let role = msg.get("role").and_then(|r| r.as_str()).unwrap_or("");
44 if role != "user" {
45 continue;
46 }
47
48 if let Some(content) = msg.get_mut("content").and_then(|c| c.as_array_mut()) {
49 for block in content.iter_mut() {
50 if block.get("type").and_then(|t| t.as_str()) != Some("tool_result") {
51 continue;
52 }
53
54 if let Some(inner_content) = block.get_mut("content") {
55 modified |= compress_content_field(inner_content, None);
56 }
57 }
58 }
59 }
60 }
61
62 if !modified {
63 return (body.to_vec(), original_size, original_size);
64 }
65
66 match serde_json::to_vec(&doc) {
67 Ok(compressed) => {
68 let compressed_size = compressed.len();
69 (compressed, original_size, compressed_size)
70 }
71 Err(_) => (body.to_vec(), original_size, original_size),
72 }
73}
74
75fn compress_content_field(content: &mut Value, tool_name: Option<&str>) -> bool {
76 match content {
77 Value::String(s) => {
78 let compressed = compress_tool_result(s, tool_name);
79 if compressed.len() < s.len() {
80 *s = compressed;
81 return true;
82 }
83 false
84 }
85 Value::Array(arr) => {
86 let mut modified = false;
87 for item in arr.iter_mut() {
88 if item.get("type").and_then(|t| t.as_str()) == Some("text") {
89 if let Some(text) = item
90 .get_mut("text")
91 .and_then(|t| t.as_str().map(String::from))
92 {
93 let compressed = compress_tool_result(&text, tool_name);
94 if compressed.len() < text.len() {
95 item["text"] = Value::String(compressed);
96 modified = true;
97 }
98 }
99 }
100 }
101 modified
102 }
103 _ => false,
104 }
105}