systemprompt-templates 0.10.2

Template registry, loading, and rendering for systemprompt.io config-as-code AI governance deployments. Handlebars-powered template engine for the MCP governance pipeline.
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

use std::path::Path;

use systemprompt_template_provider::{PartialSource, TemplateDefinition};
use tracing::{debug, info, warn};

use super::TemplateRegistry;
use crate::TemplateError;

impl TemplateRegistry {
    pub async fn initialize(&mut self) -> Result<(), TemplateError> {
        info!(
            providers = self.providers.len(),
            loaders = self.loaders.len(),
            "Initializing template registry"
        );

        if self.loaders.is_empty() {
            return Err(TemplateError::NotInitialized);
        }

        let mut all_templates: Vec<(TemplateDefinition, &str)> = Vec::new();

        for provider in &self.providers {
            for template in provider.templates() {
                all_templates.push((template, provider.provider_id()));
            }
        }

        all_templates.sort_by_key(|a| a.0.priority);

        for (template, provider_id) in all_templates {
            if self.resolved_templates.contains_key(&template.name) {
                debug!(
                    template = %template.name,
                    provider = %provider_id,
                    "Template already registered, skipping"
                );
                continue;
            }

            debug!(
                template = %template.name,
                provider = %provider_id,
                priority = template.priority,
                "Registering template"
            );

            match self.load_template(&template).await {
                Ok(content) => {
                    if let Err(e) = self
                        .handlebars
                        .register_template_string(&template.name, content)
                    {
                        warn!(
                            template = %template.name,
                            error = %e,
                            "Failed to compile template"
                        );
                        continue;
                    }
                    self.template_sources
                        .insert(template.name.clone(), provider_id.to_string());
                    self.resolved_templates
                        .insert(template.name.clone(), template);
                },
                Err(e) => {
                    warn!(
                        template = %template.name,
                        error = %e,
                        "Failed to load template"
                    );
                },
            }
        }

        self.register_partial_templates().await;

        info!(
            templates = self.resolved_templates.len(),
            "Template registry initialized"
        );

        Ok(())
    }

    async fn register_partial_templates(&mut self) {
        for component in &self.components {
            let Some(partial) = component.partial_template() else {
                continue;
            };

            let content = match &partial.source {
                PartialSource::Embedded(s) => (*s).to_string(),
                PartialSource::File(path) => match self.load_partial_file(path).await {
                    Ok(c) => c,
                    Err(e) => {
                        warn!(
                            component_id = %component.component_id(),
                            path = %path.display(),
                            error = %e,
                            "Failed to load partial template file"
                        );
                        continue;
                    },
                },
            };

            debug!(
                component_id = %component.component_id(),
                partial_name = %partial.name,
                "Registering partial template"
            );

            if let Err(e) = self
                .handlebars
                .register_template_string(&partial.name, content)
            {
                warn!(
                    component_id = %component.component_id(),
                    partial_name = %partial.name,
                    error = %e,
                    "Failed to compile partial template"
                );
            }
        }
    }

    async fn load_partial_file(&self, path: &Path) -> Result<String, TemplateError> {
        tokio::fs::read_to_string(path)
            .await
            .map_err(|e| TemplateError::LoadError {
                name: path.display().to_string(),
                message: e.to_string(),
            })
    }

    async fn load_template(
        &self,
        definition: &TemplateDefinition,
    ) -> Result<String, TemplateError> {
        for loader in &self.loaders {
            if loader.can_load(&definition.source) {
                return loader.load(&definition.source).await.map_err(|e| {
                    TemplateError::LoadError {
                        name: definition.name.clone(),
                        message: e.to_string(),
                    }
                });
            }
        }
        Err(TemplateError::NoLoader(definition.name.clone()))
    }
}