diff --git a/config-example.toml b/config-example.toml
index e2910b2..05d743c 100644
--- a/config-example.toml
+++ b/config-example.toml
@@ -1,10 +1,14 @@
-# Layered settings: CLI > active profile > globals. `--profile` selects the
-# profile, otherwise `default-profile` below is used. Vec fields append across
-# layers; scalars replace.
+# Merge rules (apply to every layering below): scalars replace, vec fields
+# append, profiles merge by name.
 #
-# `extra-config` optionally points to a second file layered on top of this one
-# using the same rules (scalars replace, vecs append, profiles merge by name).
-# Missing extra-config files are silently skipped; nesting is not supported.
+# Layers, lowest precedence first: globals -> active profile (with its
+# ancestors folded in) -> CLI flags. `--profile` selects the active profile;
+# otherwise the top-level `profile` below is used. Profiles can themselves set
+# `profile = "parent"` to inherit from another profile.
+#
+# `extra-config` optionally points to a second file layered on top of this
+# one. Missing extra-config files are silently skipped; nesting is not
+# supported.
 
 extra-config = "~/.config/agent-sandbox/extra.toml"
 
@@ -41,13 +45,17 @@ env = [
 # command = ["--model", "opus"]                              # default trailing args
 # bwrap-args = ["--tmpfs /opt/scratch"]                      # raw bwrap escape hatch
 
-default-profile = "claude"
+profile = "claude"
 
-[profile.claude]
+[profiles.claude]
 ro = ["~/.local/share/claude-code"]
 rw = ["~/.config/claude"]
+entrypoint = ["claude", "--allowedTools", "Bash(*)", "WebSearch", "WebFetch(*)", "mcp__*"]
+
+[profiles.claude-yolo]
+profile = "claude"
 entrypoint = ["claude", "--dangerously-skip-permissions"]
 
-[profile.codex]
+[profiles.codex]
 ro = ["~/.local/share/codex-cli"]
 entrypoint = ["codex", "--dangerously-bypass-approvals-and-sandbox"]
diff --git a/src/config.rs b/src/config.rs
index 97d632b..8ea7f3e 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -289,9 +289,7 @@ pub struct FileConfig {
     #[serde(flatten)]
     pub options: Options,
     #[serde(default)]
-    pub profile: HashMap<String, Options>,
-    #[serde(rename = "default-profile", default)]
-    pub default_profile: Option<String>,
+    pub profiles: HashMap<String, Options>,
     #[serde(rename = "extra-config", default)]
     pub extra_config: Option<PathBuf>,
     // Collects unrecognized keys; deny_unknown_fields is incompatible with flatten.
@@ -339,18 +337,17 @@ impl FileConfig {
     }
 
     fn merge_with(self, extra: FileConfig) -> FileConfig {
-        let mut profile = self.profile;
-        for (profile_name, profile_options) in extra.profile {
-            let merged = match profile.remove(&profile_name) {
+        let mut profiles = self.profiles;
+        for (profile_name, profile_options) in extra.profiles {
+            let merged = match profiles.remove(&profile_name) {
                 Some(existing) => existing.merge_with(profile_options),
                 None => profile_options,
             };
-            profile.insert(profile_name, merged);
+            profiles.insert(profile_name, merged);
         }
         FileConfig {
             options: self.options.merge_with(extra.options),
-            profile,
-            default_profile: extra.default_profile.or(self.default_profile),
+            profiles,
             extra_config: None,
             _unknown: HashMap::new(),
         }
@@ -367,21 +364,57 @@ impl FileConfig {
         Ok(config)
     }
 
-    fn resolve_profile(&self, name: Option<&str>) -> Result<Options, SandboxError> {
-        match name.or(self.default_profile.as_deref()) {
-            Some(n) => self
-                .profile
-                .get(n)
-                .cloned()
-                .ok_or_else(|| SandboxError::ProfileNotFound(n.to_string())),
+    fn resolve_profile(&self, selected: Option<&str>) -> Result<Options, SandboxError> {
+        match selected.or(self.options.profile.as_deref()) {
+            Some(leaf) => self.resolve_chain(leaf),
             None => Ok(Options::default()),
         }
     }
+
+    fn resolve_chain(&self, leaf: &str) -> Result<Options, SandboxError> {
+        let chain = self.collect_chain(leaf)?;
+
+        let merged = chain
+            .into_iter()
+            .rev()
+            .fold(Options::default(), |base, child| base.merge_with(child));
+
+        Ok(merged)
+    }
+
+    fn collect_chain(&self, leaf: &str) -> Result<Vec<Options>, SandboxError> {
+        let mut visited: Vec<String> = Vec::new();
+        let mut chain: Vec<Options> = Vec::new();
+        let mut current = leaf.to_string();
+
+        loop {
+            if visited.iter().any(|seen| seen == &current) {
+                visited.push(current);
+                return Err(SandboxError::ProfileCycle(visited));
+            }
+
+            let options = self
+                .profiles
+                .get(&current)
+                .cloned()
+                .ok_or_else(|| SandboxError::ProfileNotFound(current.clone()))?;
+
+            visited.push(current);
+            let parent = options.profile.clone();
+            chain.push(options);
+
+            match parent {
+                Some(p) => current = p,
+                None => return Ok(chain),
+            }
+        }
+    }
 }
 
 #[derive(Deserialize, Default, Clone)]
 #[serde(rename_all = "kebab-case", deny_unknown_fields)]
 pub struct Options {
+    pub profile: Option<String>,
     pub blacklist: Option<bool>,
     pub whitelist: Option<bool>,
     pub hardened: Option<bool>,
@@ -410,6 +443,7 @@ impl Options {
     fn merge_with(self, extra: Options) -> Options {
         let (blacklist, whitelist) = pick_mode_flags(&self, &extra);
         Options {
+            profile: extra.profile.or(self.profile),
             blacklist,
             whitelist,
             hardened: extra.hardened.or(self.hardened),
diff --git a/src/errors.rs b/src/errors.rs
index 677fbf9..daddc01 100644
--- a/src/errors.rs
+++ b/src/errors.rs
@@ -21,6 +21,7 @@ pub enum SandboxError {
         source: toml::de::Error,
     },
     ProfileNotFound(String),
+    ProfileCycle(Vec<String>),
     ConflictingMode,
     ConflictingEnvKey(String),
     InvalidEnvEntry(String),
@@ -65,6 +66,13 @@ impl std::fmt::Display for SandboxError {
                 write!(f, "cannot parse config file '{}': {source}", path.display())
             }
             Self::ProfileNotFound(name) => write!(f, "profile not found in config: {name}"),
+            Self::ProfileCycle(chain) => {
+                write!(
+                    f,
+                    "profile inheritance cycle detected: {}",
+                    chain.join(" -> ")
+                )
+            }
             Self::ConflictingMode => write!(
                 f,
                 "config section sets both blacklist and whitelist to true"
diff --git a/tests/e2e/cli.rs b/tests/e2e/cli.rs
index 18d7384..c3a789d 100644
--- a/tests/e2e/cli.rs
+++ b/tests/e2e/cli.rs
@@ -118,7 +118,7 @@ fn bwrap_arg_setenv_passes_through() {
 fn config_entrypoint_appends_passthrough_args() {
     let cfg = ConfigFile::new(
         r#"
-        [profile.test]
+        [profiles.test]
         entrypoint = ["bash", "-c"]
     "#,
     );
@@ -139,7 +139,7 @@ fn config_entrypoint_appends_passthrough_args() {
 fn config_entrypoint_falls_back_to_command_defaults() {
     let cfg = ConfigFile::new(
         r#"
-        [profile.test]
+        [profiles.test]
         entrypoint = ["bash", "-c"]
         command = ["echo default-args"]
     "#,
@@ -160,7 +160,7 @@ fn config_entrypoint_falls_back_to_command_defaults() {
 fn config_entrypoint_alone_without_command_or_passthrough() {
     let cfg = ConfigFile::new(
         r#"
-        [profile.test]
+        [profiles.test]
         entrypoint = ["bash", "-c", "echo entrypoint-only"]
     "#,
     );
@@ -214,7 +214,7 @@ fn cli_entrypoint_overrides_config_entrypoint() {
 fn config_command_alone_without_passthrough() {
     let cfg = ConfigFile::new(
         r#"
-        [profile.test]
+        [profiles.test]
         command = ["bash", "-c", "echo command-only"]
     "#,
     );
@@ -234,7 +234,7 @@ fn config_command_alone_without_passthrough() {
 fn config_command_replaced_by_passthrough() {
     let cfg = ConfigFile::new(
         r#"
-        [profile.test]
+        [profiles.test]
         command = ["bash", "-c", "echo should-not-see-this"]
     "#,
     );
diff --git a/tests/unit/config.rs b/tests/unit/config.rs
index 689a1e4..f791587 100644
--- a/tests/unit/config.rs
+++ b/tests/unit/config.rs
@@ -11,13 +11,13 @@ const FULL_CONFIG_TOML: &str = r#"
     rw = ["/tmp/a", "/tmp/b"]
     command = "zsh"
 
-    [profile.claude]
+    [profiles.claude]
     rw = ["/home/user/.config/claude"]
     ro = ["/etc/claude", "/etc/shared"]
     entrypoint = ["claude", "--dangerously-skip-permissions"]
     command = ["bash", "-c", "echo hi"]
 
-    [profile.codex]
+    [profiles.codex]
     whitelist = true
     dry-run = true
     chdir = "/home/user/project"
@@ -50,13 +50,13 @@ fn unset_vecs_default_empty() {
 
 #[test]
 fn unset_scalars_are_none() {
-    assert_eq!(CONFIG.profile["claude"].hardened, None);
+    assert_eq!(CONFIG.profiles["claude"].hardened, None);
 }
 
 #[test]
 fn profile_multi_element_vecs() {
     assert_paths(
-        &CONFIG.profile["claude"].ro,
+        &CONFIG.profiles["claude"].ro,
         &["/etc/claude", "/etc/shared"],
     );
 }
@@ -64,7 +64,7 @@ fn profile_multi_element_vecs() {
 #[test]
 fn profile_entrypoint_with_args() {
     assert_command(
-        &CONFIG.profile["claude"].entrypoint,
+        &CONFIG.profiles["claude"].entrypoint,
         &["claude", "--dangerously-skip-permissions"],
     );
 }
@@ -72,14 +72,14 @@ fn profile_entrypoint_with_args() {
 #[test]
 fn profile_command_with_args() {
     assert_command(
-        &CONFIG.profile["claude"].command,
+        &CONFIG.profiles["claude"].command,
         &["bash", "-c", "echo hi"],
     );
 }
 
 #[test]
 fn profile_kebab_case_scalars() {
-    let codex = &CONFIG.profile["codex"];
+    let codex = &CONFIG.profiles["codex"];
     assert_eq!(codex.whitelist, Some(true));
     assert_eq!(codex.dry_run, Some(true));
     assert_eq!(codex.chdir, Some(PathBuf::from("/home/user/project")));
@@ -112,7 +112,7 @@ fn build_profile_overrides_globals() {
             hardened: Some(true),
             ..Options::default()
         },
-        profile: HashMap::from([(
+        profiles: HashMap::from([(
             "relaxed".into(),
             Options {
                 hardened: Some(false),
@@ -132,7 +132,7 @@ fn build_profile_overrides_globals() {
 #[test]
 fn build_cli_flag_overrides_profile() {
     let file_config = FileConfig {
-        profile: HashMap::from([(
+        profiles: HashMap::from([(
             "nonet".into(),
             Options {
                 unshare_net: Some(false),
@@ -257,7 +257,7 @@ fn build_cli_no_dry_run_overrides_profile() {
 #[test]
 fn build_cli_mode_overrides_profile() {
     let file_config = FileConfig {
-        profile: HashMap::from([(
+        profiles: HashMap::from([(
             "wl".into(),
             Options {
                 whitelist: Some(true),
@@ -282,7 +282,7 @@ fn build_rw_paths_accumulate() {
             rw: vec!["/tmp".into()],
             ..Options::default()
         },
-        profile: HashMap::from([(
+        profiles: HashMap::from([(
             "extra".into(),
             Options {
                 rw: vec!["/usr".into()],
@@ -303,7 +303,7 @@ fn build_rw_paths_accumulate() {
 #[test]
 fn build_command_from_profile() {
     let file_config = FileConfig {
-        profile: HashMap::from([(
+        profiles: HashMap::from([(
             "test".into(),
             Options {
                 command: Some(CommandValue::WithArgs(vec![
@@ -327,7 +327,7 @@ fn build_command_from_profile() {
 #[test]
 fn build_cli_entrypoint_overrides_profile() {
     let file_config = FileConfig {
-        profile: HashMap::from([(
+        profiles: HashMap::from([(
             "test".into(),
             Options {
                 entrypoint: Some(CommandValue::Simple("/usr/bin/false".into())),
@@ -410,10 +410,13 @@ fn build_no_file_config() {
 }
 
 #[test]
-fn build_default_profile_used_when_cli_absent() {
+fn build_top_level_profile_used_when_cli_absent() {
     let file_config = FileConfig {
-        default_profile: Some("auto".into()),
-        profile: HashMap::from([(
+        options: Options {
+            profile: Some("auto".into()),
+            ..Options::default()
+        },
+        profiles: HashMap::from([(
             "auto".into(),
             Options {
                 hardened: Some(true),
@@ -427,10 +430,13 @@ fn build_default_profile_used_when_cli_absent() {
 }
 
 #[test]
-fn build_cli_profile_overrides_default_profile() {
+fn build_cli_profile_overrides_top_level_profile() {
     let file_config = FileConfig {
-        default_profile: Some("auto".into()),
-        profile: HashMap::from([
+        options: Options {
+            profile: Some("auto".into()),
+            ..Options::default()
+        },
+        profiles: HashMap::from([
             (
                 "auto".into(),
                 Options {
@@ -457,9 +463,12 @@ fn build_cli_profile_overrides_default_profile() {
 }
 
 #[test]
-fn build_missing_default_profile_errors() {
+fn build_missing_top_level_profile_errors() {
     let file_config = FileConfig {
-        default_profile: Some("nope".into()),
+        options: Options {
+            profile: Some("nope".into()),
+            ..Options::default()
+        },
         ..FileConfig::default()
     };
     assert!(matches!(
@@ -480,6 +489,227 @@ fn build_missing_profile_errors() {
     ));
 }
 
+#[test]
+fn inheritance_merges_parent_into_child() {
+    let file_config = FileConfig {
+        profiles: HashMap::from([
+            (
+                "base".into(),
+                Options {
+                    hardened: Some(true),
+                    unshare_net: Some(true),
+                    env: vec!["FROM_PARENT=1".into()],
+                    ..Options::default()
+                },
+            ),
+            (
+                "child".into(),
+                Options {
+                    profile: Some("base".into()),
+                    hardened: Some(false),
+                    seccomp: Some(false),
+                    env: vec!["FROM_CHILD=1".into()],
+                    ..Options::default()
+                },
+            ),
+        ]),
+        ..FileConfig::default()
+    };
+    let args = Args {
+        profile: Some("child".into()),
+        ..args_with_command()
+    };
+    let config = build(args, Some(file_config)).unwrap();
+
+    assert!(!config.hardened);
+    assert!(config.unshare_net);
+    assert!(!config.seccomp);
+    assert_eq!(
+        config.env,
+        vec![
+            EnvEntry::Set("FROM_PARENT".into(), "1".into()),
+            EnvEntry::Set("FROM_CHILD".into(), "1".into()),
+        ]
+    );
+}
+
+#[test]
+fn inheritance_walks_multi_level_chain() {
+    let file_config = FileConfig {
+        profiles: HashMap::from([
+            (
+                "grand".into(),
+                Options {
+                    hardened: Some(true),
+                    env: vec!["FROM_GRAND=1".into()],
+                    ..Options::default()
+                },
+            ),
+            (
+                "parent".into(),
+                Options {
+                    profile: Some("grand".into()),
+                    env: vec!["FROM_PARENT=1".into()],
+                    ..Options::default()
+                },
+            ),
+            (
+                "child".into(),
+                Options {
+                    profile: Some("parent".into()),
+                    env: vec!["FROM_CHILD=1".into()],
+                    ..Options::default()
+                },
+            ),
+        ]),
+        ..FileConfig::default()
+    };
+    let args = Args {
+        profile: Some("child".into()),
+        ..args_with_command()
+    };
+    let config = build(args, Some(file_config)).unwrap();
+
+    assert!(config.hardened);
+    assert_eq!(
+        config.env,
+        vec![
+            EnvEntry::Set("FROM_GRAND".into(), "1".into()),
+            EnvEntry::Set("FROM_PARENT".into(), "1".into()),
+            EnvEntry::Set("FROM_CHILD".into(), "1".into()),
+        ]
+    );
+}
+
+#[test]
+fn top_level_profile_walks_chain() {
+    let file_config = FileConfig {
+        options: Options {
+            profile: Some("child".into()),
+            ..Options::default()
+        },
+        profiles: HashMap::from([
+            (
+                "base".into(),
+                Options {
+                    hardened: Some(true),
+                    ..Options::default()
+                },
+            ),
+            (
+                "child".into(),
+                Options {
+                    profile: Some("base".into()),
+                    ..Options::default()
+                },
+            ),
+        ]),
+        ..FileConfig::default()
+    };
+    let config = build(args_with_command(), Some(file_config)).unwrap();
+    assert!(config.hardened);
+}
+
+#[test]
+fn inheritance_cycle_errors() {
+    let file_config = FileConfig {
+        profiles: HashMap::from([
+            (
+                "a".into(),
+                Options {
+                    profile: Some("b".into()),
+                    ..Options::default()
+                },
+            ),
+            (
+                "b".into(),
+                Options {
+                    profile: Some("a".into()),
+                    ..Options::default()
+                },
+            ),
+        ]),
+        ..FileConfig::default()
+    };
+    let args = Args {
+        profile: Some("a".into()),
+        ..args_with_command()
+    };
+    assert!(matches!(
+        build(args, Some(file_config)),
+        Err(SandboxError::ProfileCycle(_))
+    ));
+}
+
+#[test]
+fn missing_parent_profile_errors() {
+    let file_config = FileConfig {
+        profiles: HashMap::from([(
+            "child".into(),
+            Options {
+                profile: Some("ghost".into()),
+                ..Options::default()
+            },
+        )]),
+        ..FileConfig::default()
+    };
+    let args = Args {
+        profile: Some("child".into()),
+        ..args_with_command()
+    };
+    assert!(matches!(
+        build(args, Some(file_config)),
+        Err(SandboxError::ProfileNotFound(name)) if name == "ghost"
+    ));
+}
+
+#[test]
+fn inheritance_chain_spans_extra_config() {
+    let dir = TempDir::new().unwrap();
+    let base_path = dir.path().join("base.toml");
+    let extra_path = dir.path().join("extra.toml");
+
+    std::fs::write(
+        &extra_path,
+        r#"
+            [profiles.child]
+            profile = "base"
+            env = ["FROM_CHILD=1"]
+        "#,
+    )
+    .unwrap();
+    std::fs::write(
+        &base_path,
+        format!(
+            r#"
+                extra-config = "{}"
+
+                [profiles.base]
+                hardened = true
+                env = ["FROM_PARENT=1"]
+            "#,
+            extra_path.display()
+        ),
+    )
+    .unwrap();
+
+    let file_config = FileConfig::load(&base_path).unwrap();
+    let args = Args {
+        profile: Some("child".into()),
+        ..args_with_command()
+    };
+    let config = build(args, Some(file_config)).unwrap();
+
+    assert!(config.hardened);
+    assert_eq!(
+        config.env,
+        vec![
+            EnvEntry::Set("FROM_PARENT".into(), "1".into()),
+            EnvEntry::Set("FROM_CHILD".into(), "1".into()),
+        ]
+    );
+}
+
 #[test]
 fn build_conflicting_mode_errors() {
     let file_config = FileConfig {
@@ -700,7 +930,7 @@ fn build_env_accumulates_disjoint_keys() {
             env: vec!["A=global".into(), "B".into()],
             ..Options::default()
         },
-        profile: HashMap::from([(
+        profiles: HashMap::from([(
             "p".into(),
             Options {
                 env: vec!["C=profile".into()],
@@ -733,7 +963,7 @@ fn build_env_later_tier_overrides_earlier() {
             env: vec!["A=global".into()],
             ..Options::default()
         },
-        profile: HashMap::from([(
+        profiles: HashMap::from([(
             "p".into(),
             Options {
                 env: vec!["A=profile".into()],
@@ -818,7 +1048,7 @@ fn build_unsetenv_accumulates() {
             unsetenv: vec!["G".into()],
             ..Options::default()
         },
-        profile: HashMap::from([(
+        profiles: HashMap::from([(
             "p".into(),
             Options {
                 unsetenv: vec!["P".into()],
@@ -843,7 +1073,7 @@ fn build_mask_accumulates() {
             mask: vec![PathBuf::from("/tmp/a")],
             ..Options::default()
         },
-        profile: HashMap::from([(
+        profiles: HashMap::from([(
             "extra".into(),
             Options {
                 mask: vec![PathBuf::from("/tmp/b")],
@@ -876,7 +1106,7 @@ fn unknown_option_rejected() {
 #[test]
 fn unknown_profile_option_rejected() {
     let toml = r#"
-        [profile.test]
+        [profiles.test]
         hardened = true
         frobnicate = 42
     "#;
@@ -1081,7 +1311,7 @@ fn merge_options_lists_append_base_then_extra() {
 #[test]
 fn merge_file_config_profile_merged_by_name() {
     let base = FileConfig {
-        profile: HashMap::from([(
+        profiles: HashMap::from([(
             "claude".into(),
             Options {
                 rw: vec!["/a".into()],
@@ -1092,7 +1322,7 @@ fn merge_file_config_profile_merged_by_name() {
         ..FileConfig::default()
     };
     let extra = FileConfig {
-        profile: HashMap::from([
+        profiles: HashMap::from([
             (
                 "claude".into(),
                 Options {
@@ -1112,32 +1342,41 @@ fn merge_file_config_profile_merged_by_name() {
         ..FileConfig::default()
     };
     let merged = base.merge_with(extra);
-    assert_eq!(merged.profile["claude"].hardened, Some(true));
-    assert_eq!(merged.profile["claude"].rw, vec!["/a", "/b"]);
-    assert_eq!(merged.profile["codex"].unshare_net, Some(true));
+    assert_eq!(merged.profiles["claude"].hardened, Some(true));
+    assert_eq!(merged.profiles["claude"].rw, vec!["/a", "/b"]);
+    assert_eq!(merged.profiles["codex"].unshare_net, Some(true));
 }
 
 #[test]
-fn merge_file_config_default_profile_extra_overrides() {
+fn merge_file_config_top_level_profile_extra_overrides() {
     let base = FileConfig {
-        default_profile: Some("claude".into()),
+        options: Options {
+            profile: Some("claude".into()),
+            ..Options::default()
+        },
         ..FileConfig::default()
     };
     let extra = FileConfig {
-        default_profile: Some("codex".into()),
+        options: Options {
+            profile: Some("codex".into()),
+            ..Options::default()
+        },
         ..FileConfig::default()
     };
-    assert_eq!(base.merge_with(extra).default_profile, Some("codex".into()));
+    assert_eq!(base.merge_with(extra).options.profile, Some("codex".into()));
 }
 
 #[test]
-fn merge_file_config_default_profile_extra_unset_inherits() {
+fn merge_file_config_top_level_profile_extra_unset_inherits() {
     let base = FileConfig {
-        default_profile: Some("claude".into()),
+        options: Options {
+            profile: Some("claude".into()),
+            ..Options::default()
+        },
         ..FileConfig::default()
     };
     assert_eq!(
-        base.merge_with(FileConfig::default()).default_profile,
+        base.merge_with(FileConfig::default()).options.profile,
         Some("claude".into())
     );
 }