a3s-code-core 2.6.0

A3S Code Core - Embeddable AI agent library with tool execution
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134

use super::execution_state::ExecutionLoopState;
use super::AgentLoop;
use crate::llm::{Attachment, Message};
use crate::tools::ToolResult;
use crate::verification::VerificationReport;
use serde_json::Value;

pub(super) struct NormalizedToolResult {
    pub(super) output: String,
    pub(super) exit_code: i32,
    pub(super) is_error: bool,
    pub(super) metadata: Option<Value>,
    pub(super) images: Vec<Attachment>,
}

impl NormalizedToolResult {
    pub(super) fn from_execution(result: anyhow::Result<ToolResult>) -> Self {
        match result {
            Ok(result) => Self {
                output: result.output,
                exit_code: result.exit_code,
                is_error: result.exit_code != 0,
                metadata: result.metadata,
                images: result.images,
            },
            Err(error) => Self::tool_error(error.to_string()),
        }
    }

    pub(super) fn denied(output: String) -> Self {
        Self {
            output,
            exit_code: 1,
            is_error: true,
            metadata: None,
            images: Vec::new(),
        }
    }

    fn tool_error(message: String) -> Self {
        let hint = if AgentLoop::is_transient_tool_error(&message) {
            " [transient - you may retry this tool call]"
        } else {
            " [permanent - do not retry without changing the arguments]"
        };

        Self {
            output: format!("Tool execution error: {}{}", message, hint),
            exit_code: 1,
            is_error: true,
            metadata: None,
            images: Vec::new(),
        }
    }
}

impl AgentLoop {
    pub(super) fn collect_verification_report(
        reports: &mut Vec<VerificationReport>,
        metadata: &Option<Value>,
    ) {
        let Some(metadata) = metadata else {
            return;
        };
        let Some(report) = metadata.get("verification_report") else {
            return;
        };

        match serde_json::from_value::<VerificationReport>(report.clone()) {
            Ok(report) => reports.push(report),
            Err(err) => tracing::warn!(
                error = %err,
                "Ignoring malformed verification_report tool metadata"
            ),
        }
    }

    /// Returns `true` for errors that are likely transient (network, timeout, I/O contention).
    pub(super) fn is_transient_tool_error(message: &str) -> bool {
        let lower = message.to_lowercase();
        lower.contains("timeout")
            || lower.contains("timed out")
            || lower.contains("connection refused")
            || lower.contains("connection reset")
            || lower.contains("broken pipe")
            || lower.contains("temporarily unavailable")
            || lower.contains("resource temporarily unavailable")
            || lower.contains("os error 11")
            || lower.contains("os error 35")
            || lower.contains("rate limit")
            || lower.contains("too many requests")
            || lower.contains("service unavailable")
            || lower.contains("network unreachable")
    }
}

pub(super) fn push_tool_result_message(
    state: &mut ExecutionLoopState,
    tool_id: &str,
    output: &str,
    is_error: bool,
    images: Vec<Attachment>,
) {
    if images.is_empty() {
        state
            .messages
            .push(Message::tool_result(tool_id, output, is_error));
    } else {
        state.messages.push(Message::tool_result_with_images(
            tool_id, output, &images, is_error,
        ));
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn transient_tool_error_detection_marks_retryable_failures() {
        assert!(AgentLoop::is_transient_tool_error("request timed out"));
        assert!(AgentLoop::is_transient_tool_error("rate limit exceeded"));
        assert!(!AgentLoop::is_transient_tool_error("unknown argument path"));
    }

    #[test]
    fn execution_error_includes_retry_hint() {
        let transient = NormalizedToolResult::from_execution(Err(anyhow::anyhow!("timed out")));
        assert!(transient.output.contains("transient"));

        let permanent = NormalizedToolResult::from_execution(Err(anyhow::anyhow!("bad path")));
        assert!(permanent.output.contains("permanent"));
    }
}