feat: Add 'atuin config' subcommand for reading and setting config values (#3368)

Adds a new `atuin config` command with three subcommands for inspecting
and modifying `config.toml` without opening an editor.

3 files changed, 461 insertions, 14 deletions

diff --git a/crates/atuin-client/src/settings.rs b/crates/atuin-client/src/settings.rs
index b3359d19..78953320 100644
--- a/crates/atuin-client/src/settings.rs
+++ b/crates/atuin-client/src/settings.rs
@@ -1589,7 +1589,12 @@ impl Settings {
         Ok(config_file)
     }
 
-    pub fn new() -> Result<Self> {
+    /// Build a merged `Config` from defaults, config file, and environment.
+    ///
+    /// This resolves `data_dir`, initializes the data directory on disk,
+    /// and layers defaults → config file → env overrides. Both `new()` and
+    /// `get_config_value()` use this so the resolution logic lives in one place.
+    fn build_config() -> Result<Config> {
         let config_file = Self::get_config_path()?;
 
         // extract data_dir first so we can use it as the base for other path defaults
@@ -1649,21 +1654,106 @@ impl Settings {
             config_builder
         };
 
-        let config = config_builder.build()?;
-        let mut settings: Settings = config
+        // all paths should be expanded
+        let built = config_builder.build_cloned()?;
+        config_builder = [
+            "db_path",
+            "record_store_path",
+            "key_path",
+            "daemon.socket_path",
+            "daemon.pidfile_path",
+            "logs.dir",
+            "logs.search.file",
+            "logs.daemon.file",
+        ]
+        .iter()
+        .map(|key| (key, built.get_string(key).unwrap_or_default()))
+        .filter_map(|(key, value)| match Self::expand_path(value) {
+            Ok(expanded) => Some((key, expanded)),
+            Err(e) => {
+                log::warn!("failed to expand path for {key}: {e}");
+                None
+            }
+        })
+        .fold(config_builder, |builder, (key, value)| {
+            builder
+                .set_override(key, value)
+                .unwrap_or_else(|_| panic!("failed to set absolute path override for {key}"))
+        });
+
+        config_builder.build().map_err(Into::into)
+    }
+
+    /// Look up a single config value by dotted key (e.g. `"daemon.sync_frequency"`).
+    ///
+    /// Returns the effective value after merging defaults, config file, and
+    /// environment — without the side-effects of full `Settings` construction
+    /// (meta store init, path expansion, etc.).
+    pub fn get_config_value(key: &str) -> Result<String> {
+        let config = Self::build_config()?;
+        let value: config::Value = config
+            .get(key)
+            .map_err(|e| eyre!("failed to get config value '{}': {}", key, e))?;
+        Ok(Self::format_resolved_value(&value, key))
+    }
+
+    fn format_resolved_value(value: &config::Value, prefix: &str) -> String {
+        use config::ValueKind;
+
+        match &value.kind {
+            ValueKind::Nil => String::new(),
+            ValueKind::Boolean(b) => b.to_string(),
+            ValueKind::I64(i) => i.to_string(),
+            ValueKind::I128(i) => i.to_string(),
+            ValueKind::U64(u) => u.to_string(),
+            ValueKind::U128(u) => u.to_string(),
+            ValueKind::Float(f) => f.to_string(),
+            ValueKind::String(s) => s.clone(),
+            ValueKind::Array(arr) => {
+                let items: Vec<String> = arr
+                    .iter()
+                    .map(|v| Self::format_resolved_value(v, ""))
+                    .collect();
+                format!("[{}]", items.join(", "))
+            }
+            ValueKind::Table(map) => {
+                let mut lines = Vec::new();
+                let mut keys: Vec<_> = map.keys().collect();
+                keys.sort();
+
+                for k in keys {
+                    let v = &map[k];
+                    let full_key = if prefix.is_empty() {
+                        k.clone()
+                    } else {
+                        format!("{}.{}", prefix, k)
+                    };
+
+                    match &v.kind {
+                        ValueKind::Table(_) => {
+                            lines.push(Self::format_resolved_value(v, &full_key));
+                        }
+                        _ => {
+                            lines.push(format!(
+                                "{} = {}",
+                                full_key,
+                                Self::format_resolved_value(v, "")
+                            ));
+                        }
+                    }
+                }
+
+                lines.join("\n")
+            }
+        }
+    }
+
+    pub fn new() -> Result<Self> {
+        let config = Self::build_config()?;
+        let settings: Settings = config
             .try_deserialize()
             .map_err(|e| eyre!("failed to deserialize: {}", e))?;
 
-        // all paths should be expanded
-        settings.db_path = Self::expand_path(settings.db_path)?;
-        settings.record_store_path = Self::expand_path(settings.record_store_path)?;
-        settings.key_path = Self::expand_path(settings.key_path)?;
-        settings.daemon.socket_path = Self::expand_path(settings.daemon.socket_path)?;
-        settings.daemon.pidfile_path = Self::expand_path(settings.daemon.pidfile_path)?;
-        settings.logs.dir = Self::expand_path(settings.logs.dir)?;
-        settings.logs.search.file = Self::expand_path(settings.logs.search.file)?;
-        settings.logs.daemon.file = Self::expand_path(settings.logs.daemon.file)?;
-
         // Validate UI settings
         settings.ui.validate()?;
 
diff --git a/crates/atuin/src/command/client.rs b/crates/atuin/src/command/client.rs
index 7a7dc153..6ed4a17b 100644
--- a/crates/atuin/src/command/client.rs
+++ b/crates/atuin/src/command/client.rs
@@ -49,6 +49,7 @@ mod account;
 #[cfg(feature = "daemon")]
 mod daemon;
 
+mod config;
 mod default_config;
 mod doctor;
 mod dotfiles;
@@ -133,6 +134,9 @@ pub enum Cmd {
     #[command()]
     DefaultConfig,
 
+    #[command(subcommand)]
+    Config(config::Cmd),
+
     /// Run the AI assistant
     #[cfg(feature = "ai")]
     #[command(subcommand)]
@@ -325,6 +329,7 @@ impl Cmd {
             Self::History(history) => return history.run(&settings).await,
             Self::Init(init) => return init.run(&settings).await,
             Self::Doctor => return doctor::run(&settings).await,
+            Self::Config(config) => return config.run(&settings).await,
             _ => {}
         }
 
@@ -372,7 +377,7 @@ impl Cmd {
             #[cfg(feature = "daemon")]
             Self::Daemon(cmd) => cmd.run(settings, sqlite_store, db).await,
 
-            Self::History(_) | Self::Init(_) | Self::Doctor => unreachable!(),
+            Self::History(_) | Self::Init(_) | Self::Doctor | Self::Config(_) => unreachable!(),
 
             #[cfg(feature = "ai")]
             Self::Ai(cli) => atuin_ai::commands::run(cli, &settings).await,
diff --git a/crates/atuin/src/command/client/config.rs b/crates/atuin/src/command/client/config.rs
new file mode 100644
index 00000000..5ec5f7f3
--- /dev/null
+++ b/crates/atuin/src/command/client/config.rs
@@ -0,0 +1,352 @@
+use atuin_client::settings::Settings;
+use clap::{Args, Subcommand, ValueEnum};
+use eyre::Result;
+use toml_edit::{Document, DocumentMut, Item, Table, TableLike, Value};
+
+#[derive(Subcommand, Debug)]
+#[command(infer_subcommands = true)]
+pub enum Cmd {
+    /// Get a configuration value from your config.toml file
+    /// or after defaults and overrides are applied
+    #[command()]
+    Get(GetCmd),
+
+    /// Set a configuration value in your config.toml file
+    #[command()]
+    Set(SetCmd),
+
+    /// Print all configuration values from your config.toml file
+    /// in TOML format
+    ///
+    /// If a key is provided, only print the value of that key and all its children
+    #[command()]
+    Print(PrintCmd),
+}
+
+impl Cmd {
+    pub async fn run(self, settings: &Settings) -> Result<()> {
+        match self {
+            Self::Get(get) => get.run(settings).await,
+            Self::Set(set) => set.run(settings).await,
+            Self::Print(print) => print.run(settings).await,
+        }
+    }
+}
+
+/// Get a configuration value from your config.toml file,
+/// or optionally the effective value after defaults and overrides are applied.
+#[derive(Args, Debug)]
+pub struct GetCmd {
+    /// The configuration key to get
+    pub key: String,
+
+    /// Print the value after defaults and overrides are applied
+    #[arg(long, short)]
+    pub resolved: bool,
+
+    /// Print both the config file value and the resolved value
+    #[arg(long, short)]
+    pub verbose: bool,
+}
+
+impl GetCmd {
+    pub async fn run(&self, _settings: &Settings) -> Result<()> {
+        let key = self.key.trim();
+        if key.is_empty() || key.contains(char::is_whitespace) {
+            eyre::bail!("Config key must be non-empty and must not contain whitespace");
+        }
+
+        if self.verbose {
+            println!("Config file:");
+            self.print_current_value(key, "  ").await?;
+            println!("\nResolved:");
+            Self::print_effective_value(key, "  ");
+            return Ok(());
+        }
+
+        if self.resolved {
+            Self::print_effective_value(key, "");
+        } else {
+            self.print_current_value(key, "").await?;
+        }
+
+        Ok(())
+    }
+
+    async fn print_current_value(&self, key: &str, prefix: &str) -> Result<()> {
+        let config_file = Settings::get_config_path()?;
+        let config_str = tokio::fs::read_to_string(&config_file).await?;
+        let doc = config_str.parse::<Document<_>>()?;
+
+        let current = get_deep_key(&doc, key);
+
+        match current {
+            Some(item) if item.is_table() || item.is_inline_table() => {
+                let table = item
+                    .as_table_like()
+                    .expect("is_table()/is_inline_table() but no table");
+                println!("{prefix}[{key}]");
+                dump_table(table, prefix, &mut vec![key.to_string()])?;
+            }
+            Some(item) => {
+                let val = item.to_string();
+                let val = val.trim().trim_matches('"');
+                println!("{prefix}{val}");
+            }
+            None => {
+                println!("{prefix}(not set in config file)");
+            }
+        }
+
+        Ok(())
+    }
+
+    fn print_effective_value(key: &str, prefix: &str) {
+        match Settings::get_config_value(key) {
+            Ok(value) => {
+                for line in value.lines() {
+                    println!("{prefix}{line}");
+                }
+            }
+            Err(_) => {
+                println!("{prefix}(unknown key)");
+            }
+        }
+    }
+}
+
+#[derive(Args, Debug)]
+pub struct SetCmd {
+    /// The configuration key to set
+    pub key: String,
+
+    /// The value to set
+    pub value: String,
+
+    /// Store value as an explicit type
+    #[arg(long = "type", short, value_enum, default_value_t = ValueType::Auto, value_name = "TYPE")]
+    pub the_type: ValueType,
+}
+
+#[derive(ValueEnum, Debug, Clone, PartialEq, Eq)]
+pub enum ValueType {
+    /// Automatically determine the type of the value
+    Auto,
+    /// Store value as a string
+    String,
+    /// Store value as a boolean
+    Boolean,
+    /// Store value as an integer
+    Integer,
+    /// Store the value as a float
+    Float,
+}
+
+impl SetCmd {
+    pub async fn run(self, _settings: &Settings) -> Result<()> {
+        let key = self.key.trim();
+        if key.is_empty() || key.contains(char::is_whitespace) {
+            eyre::bail!("Config key must be non-empty and must not contain whitespace");
+        }
+
+        let config_file = Settings::get_config_path()?;
+        let config_str = tokio::fs::read_to_string(&config_file).await?;
+        let mut doc: DocumentMut = config_str.parse()?;
+
+        // When using auto type detection, try to match the existing value's type
+        // so we don't accidentally change e.g. "300" (string) to 300 (integer)
+        let existing_type = detect_existing_type(&doc, key);
+        let value = self.parse_value(existing_type.as_ref())?;
+        set_deep_key(&mut doc, key, value)?;
+
+        tokio::fs::write(&config_file, doc.to_string()).await?;
+
+        Ok(())
+    }
+
+    fn parse_value(&self, existing_type: Option<&ValueType>) -> Result<Value> {
+        let raw = &self.value;
+
+        // Explicit --type takes priority, then existing value type, then auto-detect
+        let effective_type = if self.the_type != ValueType::Auto {
+            &self.the_type
+        } else if let Some(existing) = existing_type {
+            existing
+        } else {
+            &ValueType::Auto
+        };
+
+        match effective_type {
+            ValueType::String => Ok(Value::from(raw.as_str())),
+            ValueType::Boolean => {
+                let b: bool = raw
+                    .parse()
+                    .map_err(|_| eyre::eyre!("invalid boolean value: {raw}"))?;
+                Ok(Value::from(b))
+            }
+            ValueType::Integer => {
+                let i: i64 = raw
+                    .parse()
+                    .map_err(|_| eyre::eyre!("invalid integer value: {raw}"))?;
+                Ok(Value::from(i))
+            }
+            ValueType::Float => {
+                let f: f64 = raw
+                    .parse()
+                    .map_err(|_| eyre::eyre!("invalid float value: {raw}"))?;
+                Ok(Value::from(f))
+            }
+            ValueType::Auto => {
+                if raw == "true" || raw == "false" {
+                    return Ok(Value::from(raw == "true"));
+                }
+                if let Ok(i) = raw.parse::<i64>() {
+                    return Ok(Value::from(i));
+                }
+                if let Ok(f) = raw.parse::<f64>() {
+                    return Ok(Value::from(f));
+                }
+                Ok(Value::from(raw.as_str()))
+            }
+        }
+    }
+}
+
+#[derive(Args, Debug)]
+pub struct PrintCmd {
+    /// Print the value of a specific key and all its children
+    pub key: Option<String>,
+}
+
+impl PrintCmd {
+    pub async fn run(&self, _settings: &Settings) -> Result<()> {
+        let config_file = Settings::get_config_path()?;
+        let config_str = tokio::fs::read_to_string(&config_file).await?;
+        let doc = config_str.parse::<Document<_>>()?;
+
+        if let Some(key) = &self.key {
+            let current = get_deep_key(&doc, key);
+
+            if let Some(current) = current {
+                if current.is_table() || current.is_inline_table() {
+                    println!("[{key}]");
+                    dump_table(
+                        current
+                            .as_table_like()
+                            .expect("is_table()/is_inline_table() but no table"),
+                        "",
+                        &mut vec![key.clone()],
+                    )?;
+                } else {
+                    println!("{}", current.to_string().trim().trim_matches('"'));
+                }
+            } else {
+                println!("key not found");
+            }
+        } else {
+            dump_table(doc.as_table(), "", &mut Vec::new())?;
+        }
+
+        Ok(())
+    }
+}
+
+fn dump_table(table: &dyn TableLike, prefix: &str, stack: &mut Vec<String>) -> Result<()> {
+    for (key, value) in table.iter() {
+        if value.is_table() || value.is_inline_table() {
+            stack.push(key.to_string());
+
+            let table = value
+                .as_table_like()
+                .expect("is_table()/is_inline_table() but no table");
+
+            println!("\n{}[{}]", prefix, stack.join("."));
+
+            dump_table(table, prefix, stack)?;
+
+            stack.pop();
+        } else {
+            println!("{prefix}{key} = {value}");
+        }
+    }
+
+    Ok(())
+}
+
+fn get_deep_key<'doc>(doc: &'doc Document<String>, key: &str) -> Option<&'doc Item> {
+    let parts = key.split('.');
+    let mut current: Option<&Item> = Some(doc.as_item());
+
+    for part in parts {
+        current = current
+            .and_then(|item| item.as_table_like())
+            .and_then(|table| table.get(part));
+    }
+
+    current
+}
+
+/// Detect the TOML type of an existing key in the document, so `set` with auto
+/// type detection preserves the original type rather than guessing from the value string.
+fn detect_existing_type(doc: &DocumentMut, key: &str) -> Option<ValueType> {
+    let parts: Vec<&str> = key.split('.').collect();
+    let mut current: &dyn TableLike = doc.as_table();
+
+    for &part in &parts[..parts.len().saturating_sub(1)] {
+        current = current.get(part)?.as_table_like()?;
+    }
+
+    let last = parts.last()?;
+    let v = current.get(last)?.as_value()?;
+
+    if v.is_str() {
+        Some(ValueType::String)
+    } else if v.is_bool() {
+        Some(ValueType::Boolean)
+    } else if v.is_integer() {
+        Some(ValueType::Integer)
+    } else if v.is_float() {
+        Some(ValueType::Float)
+    } else {
+        None
+    }
+}
+
+fn set_deep_key(doc: &mut DocumentMut, key: &str, value: Value) -> Result<()> {
+    let parts: Vec<&str> = key.split('.').collect();
+
+    if parts.is_empty() {
+        eyre::bail!("empty config key");
+    }
+
+    let mut current: &mut dyn TableLike = doc.as_table_mut();
+
+    // Navigate/create intermediate tables
+    for &part in &parts[..parts.len() - 1] {
+        if !current.contains_key(part) {
+            current.insert(part, Item::Table(Table::new()));
+        }
+        current = current
+            .get_mut(part)
+            .expect("just inserted or already exists")
+            .as_table_like_mut()
+            .ok_or_else(|| eyre::eyre!("'{}' exists but is not a table", part))?;
+    }
+
+    let last = *parts.last().unwrap();
+
+    // Don't silently overwrite a table with a scalar value
+    if let Some(existing) = current.get(last)
+        && (existing.is_table() || existing.is_inline_table())
+    {
+        eyre::bail!(
+            "'{}' is a table; use a dotted key like '{}.key' to set a value within it",
+            key,
+            key
+        );
+    }
+
+    current.insert(last, Item::Value(value));
+
+    Ok(())
+}