diff --git a/Cargo.lock b/Cargo.lock
index e55839e8..c49dc459 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -125,6 +125,15 @@ version = "1.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c3d036a3c4ab069c7b410a2ce876bd74808d2d0888a82667669f8e783a898bf1"
 
+[[package]]
+name = "arc-swap"
+version = "1.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6a3a1fd6f75306b68087b831f025c712524bcb19aad54e557b1129cfa0a2b207"
+dependencies = [
+ "rustversion",
+]
+
 [[package]]
 name = "arg_enum_proc_macro"
 version = "0.3.4"
@@ -420,6 +429,12 @@ dependencies = [
  "fs_extra",
 ]
 
+[[package]]
+name = "base62"
+version = "2.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cd637ac531c60eb7fbc4684dc061c2d7d90d73d758181aa02eeff0464b9eee4b"
+
 [[package]]
 name = "base64"
 version = "0.22.1"
@@ -526,6 +541,16 @@ dependencies = [
  "piper",
 ]
 
+[[package]]
+name = "bstr"
+version = "1.12.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5cee35f73844aa3014bb606320a6c1f010249dbdf43342fe54b5a4f6a8ed4b79"
+dependencies = [
+ "memchr",
+ "serde_core",
+]
+
 [[package]]
 name = "built"
 version = "0.8.1"
@@ -1799,6 +1824,36 @@ version = "0.25.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "151665d9be52f9bb40fc7966565d39666f2d1e69233571b71b87791c7e0528b3"
 
+[[package]]
+name = "glob"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0cc23270f6e1808e30a928bdc84dea0b9b4136a8bc82338574f23baf47bbd280"
+
+[[package]]
+name = "globset"
+version = "0.4.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "52dfc19153a48bde0cbd630453615c8151bce3a5adfac7a0aebfbf0a1e1f57e3"
+dependencies = [
+ "aho-corasick",
+ "bstr",
+ "log",
+ "regex-automata",
+ "regex-syntax",
+]
+
+[[package]]
+name = "globwalk"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93e3af942408868f6934a7b85134a3230832b9977cf66125df2f9edcfce4ddcc"
+dependencies = [
+ "bitflags 1.3.2",
+ "ignore",
+ "walkdir",
+]
+
 [[package]]
 name = "glow"
 version = "0.16.0"
@@ -2438,6 +2493,22 @@ dependencies = [
  "icu_properties",
 ]
 
+[[package]]
+name = "ignore"
+version = "0.4.26"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b915661dd01db3f05050265b2477bcc6527b3792388e2749b41623cc592be67d"
+dependencies = [
+ "crossbeam-deque",
+ "globset",
+ "log",
+ "memchr",
+ "regex-automata",
+ "same-file",
+ "walkdir",
+ "winapi-util",
+]
+
 [[package]]
 name = "image"
 version = "0.25.10"
@@ -2543,6 +2614,15 @@ dependencies = [
  "once_cell",
 ]
 
+[[package]]
+name = "itertools"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b1c173a5686ce8bfa551b3563d0c2170bf24ca44da99c7ca4bfdab5418c3fe57"
+dependencies = [
+ "either",
+]
+
 [[package]]
 name = "itertools"
 version = "0.14.0"
@@ -3115,6 +3195,15 @@ version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0676bb32a98c1a483ce53e500a81ad9c3d5b3f7c920c28c24e9cb0980d0b5bc8"
 
+[[package]]
+name = "normpath"
+version = "1.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b9985ef7269fa99f3b12437bb698381da2428743ab90f20393f399fa14cab21a"
+dependencies = [
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "nu-ansi-term"
 version = "0.50.3"
@@ -3829,6 +3918,7 @@ dependencies = [
  "rand 0.10.1",
  "reqwest 0.13.4",
  "rfd",
+ "rust-i18n",
  "serde",
  "serde_json",
  "serde_yaml",
@@ -4142,7 +4232,7 @@ dependencies = [
  "built",
  "cfg-if",
  "interpolate_name",
- "itertools",
+ "itertools 0.14.0",
  "libc",
  "libfuzzer-sys",
  "log",
@@ -4458,6 +4548,54 @@ version = "0.20.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6c20b6793b5c2fa6553b250154b78d6d0db37e72700ae35fad9387a46f487c97"
 
+[[package]]
+name = "rust-i18n"
+version = "4.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "55691a65892c33ee2de49c15ea5600c6f4a70e8eeb8e6c3cd96d2a231d230c40"
+dependencies = [
+ "globwalk",
+ "regex",
+ "rust-i18n-macro",
+ "rust-i18n-support",
+ "smallvec",
+]
+
+[[package]]
+name = "rust-i18n-macro"
+version = "4.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "30de488acadcf767d97cd48518a8da8ea9777b1c9a5beca4eab78bbf77d07309"
+dependencies = [
+ "glob",
+ "proc-macro2",
+ "quote",
+ "rust-i18n-support",
+ "serde",
+ "serde_json",
+ "serde_yaml",
+ "syn",
+]
+
+[[package]]
+name = "rust-i18n-support"
+version = "4.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aea0fef8a93c06326b66392c95a115120e609674cb2132d37d276a6b05b545b4"
+dependencies = [
+ "arc-swap",
+ "base62",
+ "globwalk",
+ "itertools 0.11.0",
+ "normpath",
+ "serde",
+ "serde_json",
+ "serde_yaml",
+ "siphasher",
+ "toml 0.8.23",
+ "triomphe",
+]
+
 [[package]]
 name = "rustc-hash"
 version = "1.1.0"
@@ -5850,6 +5988,17 @@ dependencies = [
  "tracing-serde",
 ]
 
+[[package]]
+name = "triomphe"
+version = "0.1.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dd69c5aa8f924c7519d6372789a74eac5b94fb0f8fcf0d4a97eb0bfc3e785f39"
+dependencies = [
+ "arc-swap",
+ "serde",
+ "stable_deref_trait",
+]
+
 [[package]]
 name = "try-lock"
 version = "0.2.5"
diff --git a/Cargo.toml b/Cargo.toml
index 39eadad2..ed60eaa8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,7 +3,14 @@ authors = ["Aaron Allen <hello@aaronmallen.me>"]
 description = "A one-stop-shop capsuleer manager for EVE Online."
 edition = "2024"
 homepage = "https://pod.aaronmallen.dev"
-include = ["assets/*", "migrations/*", "src/*", "LICENSE", "README.md"]
+include = [
+  "assets/*",
+  "locales/*",
+  "migrations/*",
+  "src/*",
+  "LICENSE",
+  "README.md",
+]
 license = "MIT"
 name = "pod"
 publish = false
@@ -66,6 +73,7 @@ open = "5"
 rand = "0.10"
 reqwest = { features = ["form", "gzip", "json"], version = "0.13" }
 rfd = "0.17"
+rust-i18n = "4"
 serde = "1"
 serde_json = "1"
 serde_yaml = "0.9"
diff --git a/docs/dev/README.md b/docs/dev/README.md
index b0383b35..7a98921e 100644
--- a/docs/dev/README.md
+++ b/docs/dev/README.md
@@ -4,10 +4,12 @@
 
 - [Code Style] – How we write and structure our code
 - [Commits] – How we write and structure our commits
+- [i18n] – How we localize UI strings
 - [Tasks] – How to use development scripts
 - [Testing] – How we test our code
 
 [Code Style]: code-style.md
 [Commits]: commits.md
+[i18n]: i18n.md
 [Tasks]: tasks.md
 [Testing]: testing.md
diff --git a/docs/dev/i18n.md b/docs/dev/i18n.md
new file mode 100644
index 00000000..fa2ff582
--- /dev/null
+++ b/docs/dev/i18n.md
@@ -0,0 +1,96 @@
+# Internationalization (i18n)
+
+Pod localizes its own UI chrome with [`rust-i18n`](https://crates.io/crates/rust-i18n). Translation strings live in
+TOML files under `locales/` at the repo root. The framework is wired in `src/main.rs` (the `i18n!` macro) and the
+active locale is set once at startup from the configured language.
+
+## How it is wired
+
+- `src/main.rs` declares `#[macro_use] extern crate rust_i18n;` (exposing the `t!` macro crate-wide) and calls
+  `rust_i18n::i18n!("locales", fallback = "en");` at the crate root.
+- `src/i18n.rs` exposes `i18n::set_locale(language: Language)`, which maps the `Language` enum to its rust-i18n locale
+  string via `Language::esi_code()` (the enum codes — `en`, `de`, `en-us`, `es`, `fr`, `ja`, `ko`, `ru`, `zh` — are
+  exactly the locale strings rust-i18n expects).
+- `app::boot()` calls `i18n::set_locale(accessibility.language())` once at startup, alongside the existing
+  high-contrast and scale application. A language change applies at the next restart (see ADR-0041); nothing swaps the
+  locale live mid-session.
+
+## Locale file layout — one file per feature
+
+Each feature module owns its own locale fragment. **Do not funnel strings into a single shared `locales/en.toml`.**
+rust-i18n globs `locales/**/*.{toml,yml,yaml}` and merges every file, and for `_version: 1` files (the default) it
+reads the locale from **the segment after the last dot in the filename stem**. So:
+
+```text
+locales/
+  shell.en.toml        # locale "en"      (shell.en  -> last segment "en")
+  wallet.en.toml       # locale "en"
+  assets.en.toml       # locale "en"
+  common.en.toml       # locale "en"      (shared-ui namespace)
+  wallet.de.toml       # locale "de"
+  _meta.<code>.toml     # one per locale, registers the nine ESI codes
+```
+
+Every fragment is merged into one flat key map per locale, so `locales/wallet.en.toml` and `locales/shell.en.toml`
+both contribute to the `en` locale without colliding as long as their top-level namespaces differ. This is what lets
+each feature's string-extraction task edit a different file: pick **your feature's** fragment and never touch another.
+
+The fragment filename is `<feature>.<locale>.toml`. The English baseline you author is `<feature>.en.toml`. The eight
+non-`en` locales are stubbed at the repo level (`_meta.<code>.toml`) so all nine codes register today; the
+machine-translated `<feature>.<code>.toml` fragments land later. `en-us` begins as an exact copy of `en` and is
+reconciled at the translation capstone.
+
+## Key-namespace convention
+
+Keys are dot-separated and namespaced by their origin:
+
+| Pattern                       | Use for                            | Example                            |
+|-------------------------------|------------------------------------|------------------------------------|
+| `<feature>.<area>.<key>`      | feature-module UI strings          | `wallet.journal.title`             |
+| `config.<enum>.<variant>`     | user-facing labels on domain enums | `config.feature.wallet`            |
+| `common.<key>`                | shared, cross-feature strings      | `common.cancel`                    |
+
+In a TOML fragment, group keys under their namespace as a table so the file stays a small, append-only surface:
+
+```toml
+[shell.notifications]
+mark_all_read = "Mark all read"
+title = "Notifications"
+```
+
+`<feature>` is the module name (`wallet`, `assets`, `calendar`, `industry`, `mail`, `roster`, `skills`, `settings`,
+`shell`, `splash`, ...). `<area>` groups within a feature (`journal`, `transactions`, ...). Keep variants and keys
+alphabetical, matching the project's ordering convention.
+
+## Interpolation convention
+
+Use rust-i18n named placeholders — `%{name}` in the locale value, and `name => value` (or `name = value`) when
+calling `t!`. Never build user-facing strings with `format!`; interpolate through `t!` so word order can change per
+language.
+
+```toml
+# locales/shell.en.toml
+[shell.notifications]
+footer_unread = "%{count} unread"
+```
+
+```rust
+// returns a Cow<str>; call .into_owned() / .to_string() when an owned String is needed
+let label = t!("shell.notifications.footer_unread", count => total);
+```
+
+## Missing-key behavior
+
+- A key missing in the active locale resolves to the `en` value (the `fallback = "en"` chain).
+- A key absent from every locale resolves to the key string itself and never panics.
+
+Both are covered by unit tests in `src/i18n.rs`.
+
+## Extracting strings (the per-feature task)
+
+1. Add or extend `locales/<feature>.en.toml` with the keys you are introducing, grouped under their namespace table.
+2. Replace `text("literal")` with `text(t!("<feature>.<area>.<key>"))` and `format!(...)` user-facing strings with
+   `t!("...", name => value)`.
+3. Leave the non-`en` fragments to the translation pass — author only the English baseline.
+
+See `src/app.rs` notification chrome (`shell.notifications.*`) for the reference conversion.
diff --git a/locales/_meta.de.toml b/locales/_meta.de.toml
new file mode 100644
index 00000000..5fc3b84e
--- /dev/null
+++ b/locales/_meta.de.toml
@@ -0,0 +1,2 @@
+[_meta]
+locale = "de"
diff --git a/locales/_meta.en-us.toml b/locales/_meta.en-us.toml
new file mode 100644
index 00000000..781d2ea8
--- /dev/null
+++ b/locales/_meta.en-us.toml
@@ -0,0 +1,2 @@
+[_meta]
+locale = "en-us"
diff --git a/locales/_meta.en.toml b/locales/_meta.en.toml
new file mode 100644
index 00000000..0f9e4ffe
--- /dev/null
+++ b/locales/_meta.en.toml
@@ -0,0 +1,2 @@
+[_meta]
+locale = "en"
diff --git a/locales/_meta.es.toml b/locales/_meta.es.toml
new file mode 100644
index 00000000..0540f89d
--- /dev/null
+++ b/locales/_meta.es.toml
@@ -0,0 +1,2 @@
+[_meta]
+locale = "es"
diff --git a/locales/_meta.fr.toml b/locales/_meta.fr.toml
new file mode 100644
index 00000000..d88e90fe
--- /dev/null
+++ b/locales/_meta.fr.toml
@@ -0,0 +1,2 @@
+[_meta]
+locale = "fr"
diff --git a/locales/_meta.ja.toml b/locales/_meta.ja.toml
new file mode 100644
index 00000000..b87f0adf
--- /dev/null
+++ b/locales/_meta.ja.toml
@@ -0,0 +1,2 @@
+[_meta]
+locale = "ja"
diff --git a/locales/_meta.ko.toml b/locales/_meta.ko.toml
new file mode 100644
index 00000000..cedf2298
--- /dev/null
+++ b/locales/_meta.ko.toml
@@ -0,0 +1,2 @@
+[_meta]
+locale = "ko"
diff --git a/locales/_meta.ru.toml b/locales/_meta.ru.toml
new file mode 100644
index 00000000..4ff5ed0e
--- /dev/null
+++ b/locales/_meta.ru.toml
@@ -0,0 +1,2 @@
+[_meta]
+locale = "ru"
diff --git a/locales/_meta.zh.toml b/locales/_meta.zh.toml
new file mode 100644
index 00000000..ef5bfbf5
--- /dev/null
+++ b/locales/_meta.zh.toml
@@ -0,0 +1,2 @@
+[_meta]
+locale = "zh"
diff --git a/locales/common.en.toml b/locales/common.en.toml
new file mode 100644
index 00000000..4c9313c9
--- /dev/null
+++ b/locales/common.en.toml
@@ -0,0 +1,2 @@
+[common]
+cancel = "Cancel"
diff --git a/locales/shell.en.toml b/locales/shell.en.toml
new file mode 100644
index 00000000..ad5a0ab0
--- /dev/null
+++ b/locales/shell.en.toml
@@ -0,0 +1,5 @@
+[shell.notifications]
+footer_total = "%{count} total"
+footer_unread = "%{count} unread"
+mark_all_read = "Mark all read"
+title = "Notifications"
diff --git a/src/app.rs b/src/app.rs
index 52c5d21b..186eaf79 100644
--- a/src/app.rs
+++ b/src/app.rs
@@ -42,7 +42,7 @@ use crate::{
     splash, wallet,
     wallet::contract_detail,
   },
-  mcp,
+  i18n, mcp,
   services::{crash, images, telemetry, updater},
   store,
   sync::{self, FreshnessSummary, JobKey, JobKind},
@@ -1047,6 +1047,7 @@ fn boot() -> (App, Task<Message>) {
   let settings = config::load().unwrap_or_default();
   let accessibility = *settings.accessibility();
   color::set_high_contrast(*accessibility.high_contrast());
+  i18n::set_locale(accessibility.language());
   let image_root = settings.storage().resolved_cache_dir().join("images");
   store::images::init_root(image_root);
 
@@ -2395,7 +2396,7 @@ fn notifications_panel(app: &App, nav_location: config::NavLocation) -> Element<
   };
 
   let header = Row::with_children(vec![
-    text("Notifications")
+    text(t!("shell.notifications.title"))
       .font(typography::body::MEDIUM)
       .size(typography::size::LG)
       .style(typography::colored(color::text::PRIMARY))
@@ -2474,8 +2475,10 @@ fn notifications_panel(app: &App, nav_location: config::NavLocation) -> Element<
 /// rows, mirroring the mockup's `shown.length > 0` guard.
 fn notifications_footer_label(tab: NotificationTab, total: usize, history_count: usize) -> Option<String> {
   match tab {
-    NotificationTab::New => (total > 0).then(|| format!("{total} unread")),
-    NotificationTab::History => (history_count > 0).then(|| format!("{total} total")),
+    NotificationTab::New => (total > 0).then(|| t!("shell.notifications.footer_unread", count => total).into_owned()),
+    NotificationTab::History => {
+      (history_count > 0).then(|| t!("shell.notifications.footer_total", count => total).into_owned())
+    }
   }
 }
 
@@ -2486,7 +2489,7 @@ fn mark_all_read_button<'a>(enabled: bool) -> button::Button<'a, Message> {
     color::text::tertiary()
   };
   let button = button(
-    text("Mark all read")
+    text(t!("shell.notifications.mark_all_read"))
       .font(typography::body::MEDIUM)
       .size(typography::size::XS_PLUS)
       .style(move |_| text::Style {
diff --git a/src/i18n.rs b/src/i18n.rs
index f2aec935..093dc802 100644
--- a/src/i18n.rs
+++ b/src/i18n.rs
@@ -4,3 +4,44 @@ mod language;
 // nothing outside this module references it yet, so it reads as unused until those land.
 #[allow(unused_imports)]
 pub use language::Language;
+
+pub fn set_locale(language: Language) {
+  rust_i18n::set_locale(language.esi_code());
+}
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+
+  mod set_locale {
+    use super::*;
+
+    #[test]
+    fn it_resolves_a_key_in_the_active_locale() {
+      set_locale(Language::En);
+
+      assert_eq!(t!("shell.notifications.title"), "Notifications");
+    }
+
+    #[test]
+    fn it_interpolates_a_named_placeholder() {
+      set_locale(Language::En);
+
+      assert_eq!(t!("shell.notifications.footer_unread", count => 3), "3 unread");
+    }
+
+    #[test]
+    fn it_falls_back_to_en_for_a_missing_locale() {
+      set_locale(Language::EnUs);
+
+      assert_eq!(t!("shell.notifications.title"), "Notifications");
+    }
+
+    #[test]
+    fn it_returns_the_key_for_an_absent_key_without_panicking() {
+      set_locale(Language::En);
+
+      assert_eq!(t!("totally.absent.key"), "totally.absent.key");
+    }
+  }
+}
diff --git a/src/main.rs b/src/main.rs
index f1168bea..0abd1d6e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,5 +1,10 @@
 #![cfg_attr(target_os = "windows", windows_subsystem = "windows")]
 
+#[macro_use]
+extern crate rust_i18n;
+
+rust_i18n::i18n!("locales", fallback = "en");
+
 mod app;
 mod clients;
 mod config;