Library API Reference

This document provides comprehensive API documentation for the SwissArmyHammer Rust library.

Core Types

Prompt

The Prompt struct represents a single prompt with metadata and template content.

pub struct Prompt {
    pub name: String,
    pub content: String,
    pub description: Option<String>,
    pub category: Option<String>,
    pub tags: Vec<String>,
    pub arguments: Vec<ArgumentSpec>,
    pub file_path: Option<PathBuf>,
}

Methods

• new(name: &str, content: &str) -> Self - Create a new prompt
• with_description(self, description: &str) -> Self - Add a description (builder pattern)
• with_category(self, category: &str) -> Self - Add a category (builder pattern)
• add_tag(self, tag: &str) -> Self - Add a tag (builder pattern)
• add_argument(self, arg: ArgumentSpec) -> Self - Add an argument specification
• render(&self, args: &HashMap<String, String>) -> Result<String> - Render the prompt with arguments
• validate_arguments(&self, args: &HashMap<String, String>) -> Result<()> - Validate provided arguments

Example

use swissarmyhammer::{Prompt, ArgumentSpec};
use std::collections::HashMap;

let prompt = Prompt::new("greet", "Hello {{name}}!")
    .with_description("A greeting prompt")
    .add_argument(ArgumentSpec {
        name: "name".to_string(),
        description: Some("Name to greet".to_string()),
        required: true,
        default: None,
        type_hint: Some("string".to_string()),
    });

let mut args = HashMap::new();
args.insert("name".to_string(), "World".to_string());
let result = prompt.render(&args)?;
// result: "Hello World!"

ArgumentSpec

Defines the specification for a prompt argument.

pub struct ArgumentSpec {
    pub name: String,
    pub description: Option<String>,
    pub required: bool,
    pub default: Option<String>,
    pub type_hint: Option<String>,
}

PromptLibrary

The main interface for managing collections of prompts.

pub struct PromptLibrary {
    // internal fields...
}

Methods

• new() -> Self - Create a new empty library
• add_directory<P: AsRef<Path>>(&mut self, path: P) -> Result<()> - Load prompts from directory
• add_prompt(&mut self, prompt: Prompt) - Add a single prompt
• get(&self, name: &str) -> Result<&Prompt> - Get a prompt by name
• list_prompts(&self) -> Vec<&Prompt> - List all prompts
• find_by_category(&self, category: &str) -> Vec<&Prompt> - Find prompts by category
• find_by_tag(&self, tag: &str) -> Vec<&Prompt> - Find prompts by tag
• remove(&mut self, name: &str) -> Option<Prompt> - Remove a prompt

Example

use swissarmyhammer::PromptLibrary;

let mut library = PromptLibrary::new();
library.add_directory("./prompts")?;

let prompt = library.get("code-review")?;
let rendered = prompt.render(&args)?;

PromptLoader

Handles loading prompts from various sources.

pub struct PromptLoader {
    // internal fields...
}

Methods

• new() -> Self - Create a new loader
• load_file<P: AsRef<Path>>(&self, path: P) -> Result<Prompt> - Load single prompt file
• load_directory<P: AsRef<Path>>(&self, path: P) -> Result<Vec<Prompt>> - Load all prompts from directory
• load_string(&self, name: &str, content: &str) -> Result<Prompt> - Load prompt from string

Template Engine

Template

Wrapper for Liquid templates with custom filters.

pub struct Template {
    // internal fields...
}

Methods

• new(template_str: &str) -> Result<Self> - Create template from string
• render(&self, args: &HashMap<String, String>) -> Result<String> - Render with arguments
• raw(&self) -> &str - Get the raw template string

TemplateEngine

Manages template parsing and custom filters.

pub struct TemplateEngine {
    // internal fields...
}

Methods

• new() -> Self - Create new engine
• default_parser() -> Parser - Get default Liquid parser with custom filters
• register_filter<F>(&mut self, name: &str, filter: F) - Register custom filter

Storage

PromptStorage

High-level storage interface for prompts.

pub trait PromptStorage {
    fn store_prompt(&mut self, prompt: &Prompt) -> Result<()>;
    fn load_prompt(&self, name: &str) -> Result<Prompt>;
    fn list_prompts(&self) -> Result<Vec<String>>;
    fn delete_prompt(&mut self, name: &str) -> Result<()>;
}

StorageBackend

Low-level storage abstraction.

pub trait StorageBackend {
    fn read(&self, key: &str) -> Result<Vec<u8>>;
    fn write(&mut self, key: &str, data: &[u8]) -> Result<()>;
    fn delete(&mut self, key: &str) -> Result<()>;
    fn list(&self) -> Result<Vec<String>>;
}

Search

Available with the search feature

SearchEngine

Full-text search functionality for prompts.

pub struct SearchEngine {
    // internal fields...
}

Methods

• new() -> Result<Self> - Create new search engine
• index_prompt(&mut self, prompt: &Prompt) -> Result<()> - Add prompt to search index
• search(&self, query: &str) -> Result<Vec<SearchResult>> - Search for prompts

SearchResult

Represents a search result.

pub struct SearchResult {
    pub name: String,
    pub score: f32,
    pub snippet: Option<String>,
}

MCP Integration

Available with the mcp feature

McpServer

Model Context Protocol server implementation.

pub struct McpServer {
    // internal fields...
}

Methods

• new(library: PromptLibrary) -> Self - Create server with prompt library
• run(&mut self) -> Result<()> - Start the MCP server

Plugin System

SwissArmyHammerPlugin

Trait for creating plugins.

pub trait SwissArmyHammerPlugin {
    fn name(&self) -> &str;
    fn filters(&self) -> Vec<Box<dyn CustomLiquidFilter>>;
}

CustomLiquidFilter

Trait for custom Liquid template filters.

pub trait CustomLiquidFilter {
    fn name(&self) -> &str;
    fn filter(&self, input: &str, args: &[&str]) -> Result<String>;
}

PluginRegistry

Manages registered plugins and filters.

pub struct PluginRegistry {
    // internal fields...
}

Methods

• new() -> Self - Create new registry
• register_plugin<P: SwissArmyHammerPlugin>(&mut self, plugin: P) - Register plugin
• get_filters(&self) -> Vec<&dyn CustomLiquidFilter> - Get all registered filters

Error Handling

SwissArmyHammerError

Main error type for the library.

pub enum SwissArmyHammerError {
    Io(std::io::Error),
    Template(String),
    PromptNotFound(String),
    Config(String),
    Storage(String),
    Serialization(serde_yaml::Error),
    Other(String),
}

Result Type

Convenient result type alias.

pub type Result<T> = std::result::Result<T, SwissArmyHammerError>;

Feature Flags

The library supports several optional features:

• search - Enables full-text search functionality
• mcp - Enables Model Context Protocol server support

Enable features in your Cargo.toml:

[dependencies]
swissarmyhammer = { version = "0.1", features = ["search", "mcp"] }

Complete Example

use swissarmyhammer::{PromptLibrary, ArgumentSpec, Result};
use std::collections::HashMap;

fn main() -> Result<()> {
    // Create library and load prompts
    let mut library = PromptLibrary::new();
    library.add_directory("./prompts")?;
    
    // Get a prompt
    let prompt = library.get("code-review")?;
    
    // Prepare arguments
    let mut args = HashMap::new();
    args.insert("code".to_string(), "fn main() { println!(\"Hello\"); }".to_string());
    args.insert("language".to_string(), "rust".to_string());
    
    // Render the prompt
    let rendered = prompt.render(&args)?;
    println!("{}", rendered);
    
    Ok(())
}

Advanced Usage

Custom Filters

Create custom Liquid filters for domain-specific transformations:

use swissarmyhammer::{CustomLiquidFilter, PluginRegistry, TemplateEngine};

struct UppercaseFilter;

impl CustomLiquidFilter for UppercaseFilter {
    fn name(&self) -> &str { "uppercase" }
    
    fn filter(&self, input: &str, _args: &[&str]) -> Result<String> {
        Ok(input.to_uppercase())
    }
}

let mut registry = PluginRegistry::new();
registry.register_filter("uppercase", Box::new(UppercaseFilter));

Storage Backends

Implement custom storage backends:

use swissarmyhammer::{StorageBackend, Result};

struct DatabaseBackend {
    // database connection...
}

impl StorageBackend for DatabaseBackend {
    fn read(&self, key: &str) -> Result<Vec<u8>> {
        // Read from database
        todo!()
    }
    
    fn write(&mut self, key: &str, data: &[u8]) -> Result<()> {
        // Write to database
        todo!()
    }
    
    // ... implement other methods
}

For more examples and advanced usage patterns, see the Library Examples page.