tandem-server 0.4.23

HTTP server for Tandem engine APIs
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

use serde::{Deserialize, Serialize};
use sha2::{Digest, Sha256};

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PromptFragment {
    pub id: String,
    pub phase: String,
    pub content: String,
}

#[derive(Debug, Clone, Serialize, Deserialize, Default)]
pub struct PromptComposeInput {
    #[serde(default)]
    pub base_prompt: String,
    #[serde(default)]
    pub fragments: Vec<PromptFragment>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PromptComposeOutput {
    pub prompt: String,
    pub composition_hash: String,
    pub ordered_fragment_ids: Vec<String>,
}

pub fn compose(input: PromptComposeInput) -> PromptComposeOutput {
    let mut fragments = input.fragments.clone();
    fragments.sort_by(|a, b| {
        phase_rank(&a.phase)
            .cmp(&phase_rank(&b.phase))
            .then_with(|| a.id.cmp(&b.id))
            .then_with(|| a.content.cmp(&b.content))
    });

    let mut sections = Vec::new();
    if !input.base_prompt.trim().is_empty() {
        sections.push(input.base_prompt.trim().to_string());
    }
    let ordered_fragment_ids = fragments.iter().map(|f| f.id.clone()).collect::<Vec<_>>();
    for fragment in &fragments {
        if fragment.content.trim().is_empty() {
            continue;
        }
        sections.push(format!(
            "[{}:{}]\n{}",
            fragment.phase.trim().to_ascii_lowercase(),
            fragment.id.trim(),
            fragment.content.trim()
        ));
    }
    let prompt = sections.join("\n\n---\n\n");
    let composition_hash = format!("{:x}", Sha256::digest(prompt.as_bytes()));
    PromptComposeOutput {
        prompt,
        composition_hash,
        ordered_fragment_ids,
    }
}

fn phase_rank(phase: &str) -> usize {
    match phase.trim().to_ascii_lowercase().as_str() {
        "core" => 0,
        "domain" => 1,
        "style" => 2,
        "safety" => 3,
        _ => 99,
    }
}

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

    #[test]
    fn compose_is_deterministic_by_phase_and_id() {
        let out = compose(PromptComposeInput {
            base_prompt: "Base".to_string(),
            fragments: vec![
                PromptFragment {
                    id: "zeta".to_string(),
                    phase: "style".to_string(),
                    content: "Style Z".to_string(),
                },
                PromptFragment {
                    id: "alpha".to_string(),
                    phase: "core".to_string(),
                    content: "Core A".to_string(),
                },
                PromptFragment {
                    id: "beta".to_string(),
                    phase: "style".to_string(),
                    content: "Style B".to_string(),
                },
                PromptFragment {
                    id: "safe".to_string(),
                    phase: "safety".to_string(),
                    content: "Do no harm".to_string(),
                },
            ],
        });
        assert_eq!(
            out.ordered_fragment_ids,
            vec![
                "alpha".to_string(),
                "beta".to_string(),
                "zeta".to_string(),
                "safe".to_string()
            ]
        );
        let out2 = compose(PromptComposeInput {
            base_prompt: "Base".to_string(),
            fragments: vec![
                PromptFragment {
                    id: "safe".to_string(),
                    phase: "safety".to_string(),
                    content: "Do no harm".to_string(),
                },
                PromptFragment {
                    id: "beta".to_string(),
                    phase: "style".to_string(),
                    content: "Style B".to_string(),
                },
                PromptFragment {
                    id: "alpha".to_string(),
                    phase: "core".to_string(),
                    content: "Core A".to_string(),
                },
                PromptFragment {
                    id: "zeta".to_string(),
                    phase: "style".to_string(),
                    content: "Style Z".to_string(),
                },
            ],
        });
        assert_eq!(out.prompt, out2.prompt);
        assert_eq!(out.composition_hash, out2.composition_hash);
    }
}