langgraph-checkpoint-rs 0.1.0

Core checkpointing traits and interfaces for LangGraph applications in Rust
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
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155

use std::collections::HashMap;
use serde_json::Value as JsonValue;

/// RunnableConfig - the universal configuration type for all LangGraph operations.
///
/// Replaces langchain-core's RunnableConfig TypedDict.
/// The "configurable" key holds runtime configuration like thread_id, checkpoint_id, etc.
pub type RunnableConfig = HashMap<String, JsonValue>;

/// Extension trait for RunnableConfig convenience methods
pub trait RunnableConfigExt {
    fn new() -> Self;
    fn get_configurable(&self) -> Option<&JsonValue>;
    fn get_thread_id(&self) -> Option<&str>;
    fn get_checkpoint_id(&self) -> Option<&str>;
    fn get_checkpoint_ns(&self) -> &str;
    fn get_run_id(&self) -> Option<&str>;
    fn get_recursion_limit(&self) -> Option<u64>;
    fn with_recursion_limit(self, limit: u64) -> Self;
}

impl RunnableConfigExt for RunnableConfig {
    fn new() -> Self {
        HashMap::new()
    }

    fn get_configurable(&self) -> Option<&JsonValue> {
        self.get("configurable")
    }

    fn get_thread_id(&self) -> Option<&str> {
        self.get("configurable")
            .and_then(|c| c.get("thread_id"))
            .and_then(|v| v.as_str())
    }

    fn get_checkpoint_id(&self) -> Option<&str> {
        self.get("configurable")
            .and_then(|c| c.get("checkpoint_id"))
            .and_then(|v| v.as_str())
    }

    fn get_checkpoint_ns(&self) -> &str {
        self.get("configurable")
            .and_then(|c| c.get("checkpoint_ns"))
            .and_then(|v| v.as_str())
            .unwrap_or("")
    }

    fn get_run_id(&self) -> Option<&str> {
        self.get("configurable")
            .and_then(|c| c.get("run_id"))
            .and_then(|v| v.as_str())
    }

    fn get_recursion_limit(&self) -> Option<u64> {
        self.get("recursion_limit").and_then(|v| v.as_u64())
    }

    fn with_recursion_limit(mut self, limit: u64) -> Self {
        self.insert("recursion_limit".to_string(), serde_json::json!(limit));
        self
    }
}

/// Merge two configs, with override taking precedence
pub fn merge_configs(base: &RunnableConfig, override_config: &RunnableConfig) -> RunnableConfig {
    let mut result = base.clone();
    for (k, v) in override_config {
        if k == "configurable" {
            if let (Some(base_conf), Some(override_conf)) = (base.get("configurable"), v.as_object()) {
                if let Some(mut merged) = base_conf.as_object().cloned() {
                    for (ck, cv) in override_conf {
                        merged.insert(ck.clone(), cv.clone());
                    }
                    result.insert(k.clone(), JsonValue::Object(merged));
                    continue;
                }
            }
        }
        result.insert(k.clone(), v.clone());
    }
    result
}

/// Patch a config with specific fields
pub fn patch_config(
    config: &RunnableConfig,
    tags: Option<&[&str]>,
    metadata: Option<&HashMap<String, JsonValue>>,
    callbacks: Option<&JsonValue>,
) -> RunnableConfig {
    let mut result = config.clone();
    if let Some(tags) = tags {
        result.insert("tags".to_string(), JsonValue::Array(
            tags.iter().map(|t| JsonValue::String(t.to_string())).collect()
        ));
    }
    if let Some(metadata) = metadata {
        result.insert("metadata".to_string(), serde_json::to_value(metadata).unwrap_or_default());
    }
    if let Some(callbacks) = callbacks {
        result.insert("callbacks".to_string(), callbacks.clone());
    }
    result
}

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

    #[test]
    fn test_merge_configs() {
        let mut base = RunnableConfig::new();
        base.insert("tags".to_string(), serde_json::json!(["tag1"]));
        base.insert("configurable".to_string(), serde_json::json!({
            "thread_id": "t1",
            "key1": "val1",
        }));

        let mut override_config = RunnableConfig::new();
        override_config.insert("configurable".to_string(), serde_json::json!({
            "thread_id": "t2",
            "key2": "val2",
        }));

        let merged = merge_configs(&base, &override_config);
        let conf = merged.get("configurable").unwrap();
        assert_eq!(conf.get("thread_id").unwrap().as_str().unwrap(), "t2");
        assert_eq!(conf.get("key1").unwrap().as_str().unwrap(), "val1");
        assert_eq!(conf.get("key2").unwrap().as_str().unwrap(), "val2");
    }

    #[test]
    fn test_config_ext() {
        let mut config = RunnableConfig::new();
        config.insert("configurable".to_string(), serde_json::json!({
            "thread_id": "t1",
            "checkpoint_id": "cp1",
        }));

        assert_eq!(config.get_thread_id(), Some("t1"));
        assert_eq!(config.get_checkpoint_id(), Some("cp1"));
        assert_eq!(config.get_checkpoint_ns(), "");
    }

    #[test]
    fn test_recursion_limit() {
        let config = RunnableConfig::new().with_recursion_limit(10);
        assert_eq!(config.get_recursion_limit(), Some(10));

        let config = RunnableConfig::new();
        assert_eq!(config.get_recursion_limit(), None);
    }
}