Config

The config module loads settings from .towl.toml, merges environment variables, and provides the init command for generating default configuration.

TowlConfig

#![allow(unused)]
fn main() {
pub struct TowlConfig {
    pub parsing: ParsingConfig,
    pub github: GitHubConfig,
    pub llm: LlmConfig,
}
}

TowlConfig::load

#![allow(unused)]
fn main() {
impl TowlConfig {
    pub fn load(path: Option<&PathBuf>) -> Result<Self, TowlConfigError>;
}
}

Loads configuration with this precedence:

1. Built-in defaults
2. Config file resolved as: explicit path argument > TOWL_CONFIG env var > .towl.toml
3. Git remote auto-detection for owner/repo
4. Environment variable overrides (TOWL_GITHUB_*, TOWL_LLM_*)

If no config file exists, defaults are used without error.

init

#![allow(unused)]
fn main() {
pub async fn init(path: &Path, force: bool) -> Result<(), TowlConfigError>
}

Creates a .towl.toml file at the given path. Validates that a GitHub git remote exists but does not write owner/repo to the file (they are always detected at runtime).

• Fails if the file already exists (unless force is true)
• Validates the path for traversal attacks
• Serializes ParsingConfig and LlmConfig defaults to TOML

ParsingConfig

#![allow(unused)]
fn main() {
pub struct ParsingConfig {
    pub file_extensions: HashSet<String>,
    pub exclude_patterns: Vec<String>,
    pub include_context_lines: usize,
    pub comment_prefixes: Vec<String>,
    pub todo_patterns: Vec<String>,
    pub function_patterns: Vec<String>,
}
}

All fields have defaults via #[serde(default)]:

Each pattern array is limited to MAX_CONFIG_PATTERNS (100) entries.

GitHubConfig

#![allow(unused)]
fn main() {
pub struct GitHubConfig {
    pub token: SecretString,
    pub owner: Owner,
    pub repo: Repo,
    pub rate_limit_delay_ms: u64,
}
}

• token is stored as secrecy::SecretString and masked in debug/display output
• owner and repo are auto-detected from git remote get-url origin at runtime (not serialised to config)
• rate_limit_delay_ms adds a delay between GitHub API calls (default: 1000ms)

Environment Variable Overrides

Owner / Repo

Validated newtype wrappers providing type safety:

#![allow(unused)]
fn main() {
pub struct Owner(String);
pub struct Repo(String);
}

try_new

#![allow(unused)]
fn main() {
pub fn try_new(s: impl Into<String>) -> Result<Self, TowlConfigError>
}

Constructs a new Owner or Repo, rejecting values exceeding MAX_CONFIG_STRING_LENGTH (512 characters).

Errors:

• ConfigValueTooLong – Value exceeds 512 characters

Both also implement:

• Display, Default, Debug, Clone, PartialEq, Eq
• Serialize, Deserialize

LlmConfig

#![allow(unused)]
fn main() {
pub struct LlmConfig {
    pub provider: String,
    pub model: String,
    pub base_url: Option<String>,
    pub api_key: SecretString,
    pub max_concurrent_analyses: usize,
    pub max_analyse_count: usize,
    pub max_tokens: u32,
    pub max_retries: usize,
    pub command: Option<String>,
    pub args: Option<Vec<String>>,
}
}

• api_key is stored as secrecy::SecretString and masked in debug output (env-only via TOWL_LLM_API_KEY)
• provider selects the LLM backend: "claude", "openai", "claude-code", or "codex"
• command and args allow overriding the CLI binary path and arguments for CLI providers

Environment Variable Overrides

GitRepoInfo (internal)

#![allow(unused)]
fn main() {
pub(crate) struct GitRepoInfo {
    pub owner: Owner,
    pub repo: Repo,
}
}

from_path

#![allow(unused)]
fn main() {
pub(crate) async fn from_path<P: AsRef<Path>>(path: P) -> Result<Self, TowlConfigError>
}

Internal function that discovers the git remote URL by running git remote get-url origin and parses the owner and repo name. Supports both HTTPS and SSH URL formats. Not part of the public API.

Errors:

• GitRepoNotFound – Not inside a git repository
• GitRemoteNotFound – No origin remote configured
• GitInvalidUrl – Could not parse owner/repo from the URL

Errors

#![allow(unused)]
fn main() {
pub enum TowlConfigError {
    PathTraversalAttempt(PathBuf),
    ConfigAlreadyExists(PathBuf),
    WriteToFileError(PathBuf, std::io::Error),
    UnableToParseToml(toml::ser::Error),
    CouldNotCreateConfig(ConfigError),
    GitRepoNotFound { message: String },
    GitRemoteNotFound { message: String },
    GitInvalidUrl { url: String, message: String },
    TooManyConfigPatterns { field: String, count: usize, max_allowed: usize },
    ConfigValueTooLong { field: String, length: usize, max_length: usize },
    ContextLinesOutOfRange { value: usize, min: usize, max: usize },
}
}

Constants