diff --git a/.prettierignore b/.prettierignore
index d31480228..87bd3e86c 100644
--- a/.prettierignore
+++ b/.prettierignore
@@ -29,3 +29,8 @@ scripts/bench/results
 # Golden copies of the backup file and the restored account, written by the
 # parity test itself (BACKUP_PARITY_WRITE=1), so a rewrite diffs cleanly.
 tests/integration/__golden__
+
+# inlang writes its working files (cache, metadata, README) next to the
+# project settings when its CLI or SDK runs; only settings.json is tracked.
+project.inlang/*
+!project.inlang/settings.json
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index cb70d27cb..d30803d6b 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -134,6 +134,26 @@ To suggest a fix or improvement:
 3. Edit `messages/<locale>.json`. Keep the JSON valid; the i18n integrity test will flag missing or extra keys against `en.json` before CI accepts the PR.
 4. Open a PR titled `i18n(<locale>): <area>`. Describe what was unclear, awkward, or wrong in the previous wording.
 
+### Translating in the browser
+
+Every locale can be edited in [Fink](https://fink.inlang.com/?repo=MBombeck/HealthLog&project=project.inlang), inlang's browser editor, without cloning the repository. Fink reads `project.inlang/settings.json`, which points it at `messages/<locale>.json`, shows each message next to its translations, and flags strings that are missing or use other placeholders than English.
+
+1. Open the link and sign in with GitHub.
+2. Without write access to this repository, choose **Fork**. Fink asks you to install the Inlang GitHub App on your own account so it can push to your fork.
+3. Edit, then choose **Push**. Fink commits to the fork; **Open pull request** takes you to GitHub's compare page, where you submit the change against `main`.
+
+Fink writes the same nested JSON this repository uses and changes only the lines you edited. A string you add for a key the locale did not have yet goes to the end of its section instead of the position it has in `en.json`, which is harmless.
+
+What a reviewer checks on a translation pull request:
+
+- Only `messages/*.json` changed, and only the strings the description names.
+- Every `{placeholder}` of the English string is still there and spelled the same. The i18n integrity test fails the build otherwise.
+- Medical terms are the ones the language's clinical guidelines use, and the register matches the rest of the locale (`du` in German, `você` in Brazilian Portuguese).
+- Words the app or the Telegram bot matches literally stay as they are: slash commands, `taken <name>`, and the unit symbols.
+- Machine translation is fine as a first draft, but someone who reads the language has gone through every string before the pull request is opened, and the description says so.
+
+To run the checks Fink shows on a local checkout: `npx @inlang/cli@3.4.4 check --project ./project.inlang`. It reads the files and changes nothing.
+
 ### Adding a new locale
 
 If you want to introduce a locale that isn't shipped (e.g. `sv`, `cs`):
@@ -141,9 +161,8 @@ If you want to introduce a locale that isn't shipped (e.g. `sv`, `cs`):
 1. Open an issue first using the **Translation request** template. We'll confirm the locale is in scope and decide whether it joins the AI-initial-community-maintained tier or the maintained tier.
 2. Copy `messages/en.json` to `messages/<locale>.json`.
 3. Translate. AI assistance is welcome as a starting point but the PR description should note whether it's an AI-initial pass or a fully human-reviewed one — that information drives the banner state.
-4. Add the locale to the supported list in `src/lib/i18n/locales.ts` (or wherever the registry lives — grep `SUPPORTED_LOCALES`).
-5. The Coach system prompts at `src/lib/ai/prompts/coach-prompt.ts` and `src/lib/ai/prompts/insight-generator.ts` and the doctor-report PDF strings need translation too. Include those in the same PR.
-6. Run `pnpm test -- i18n-integrity` locally before submitting.
+4. Add the locale to `locales` in `src/lib/i18n/config.ts` and to `locales` in `project.inlang/settings.json`, then run `pnpm typecheck`. Every per-locale table that still lacks the new locale fails to compile, and that list is the work: date and number formatting, the reply-language footers of the Coach and insights prompts, the outbound safety banks, the prose-grounding patterns and the no-key fallback copy. Include those in the same PR.
+5. Run `pnpm test` before submitting. The i18n guards hold the new bundle to the English keys and placeholders.
 
 ### Style guide for translators
 
@@ -156,7 +175,7 @@ If you want to introduce a locale that isn't shipped (e.g. `sv`, `cs`):
 
 ### Long-term
 
-When the community grows beyond ad-hoc PRs, we'll spin up a self-hosted [Weblate](https://weblate.org/) instance. That replaces the JSON-PR workflow with a web UI but keeps every translation under our own roof — no third-party telemetry. Tracking issue: `v1.6 — Weblate self-hosted on edge-01`.
+Fink covers browser editing today. It edits the files in this repository directly and keeps no copy of the translations anywhere else. If the community outgrows it, a self-hosted [Weblate](https://weblate.org/) instance remains the fallback. Tracking issue: `v1.6 — Weblate self-hosted on edge-01`.
 
 ## Code of Conduct
 
diff --git a/README.md b/README.md
index 644499bfa..299fa3065 100644
--- a/README.md
+++ b/README.md
@@ -109,13 +109,14 @@ Next.js 16 (App Router, React Server Components), TypeScript strict, PostgreSQL
 
 ## Documentation
 
-|                        |                                                  |
-| ---------------------- | ------------------------------------------------ |
-| User and operator docs | [docs.healthlog.dev](https://docs.healthlog.dev) |
-| Release history        | [CHANGELOG.md](CHANGELOG.md)                     |
-| API contract           | [`docs/api/openapi.yaml`](docs/api/openapi.yaml) |
-| Security policy        | [SECURITY.md](SECURITY.md)                       |
-| Contributing           | [CONTRIBUTING.md](CONTRIBUTING.md)               |
+|                        |                                                              |
+| ---------------------- | ------------------------------------------------------------ |
+| User and operator docs | [docs.healthlog.dev](https://docs.healthlog.dev)             |
+| Release history        | [CHANGELOG.md](CHANGELOG.md)                                 |
+| API contract           | [`docs/api/openapi.yaml`](docs/api/openapi.yaml)             |
+| Security policy        | [SECURITY.md](SECURITY.md)                                   |
+| Contributing           | [CONTRIBUTING.md](CONTRIBUTING.md)                           |
+| Translating            | [CONTRIBUTING.md#translations](CONTRIBUTING.md#translations) |
 
 ## Status
 
diff --git a/project.inlang/settings.json b/project.inlang/settings.json
new file mode 100644
index 000000000..f040a027d
--- /dev/null
+++ b/project.inlang/settings.json
@@ -0,0 +1,11 @@
+{
+  "$schema": "https://inlang.com/schema/project-settings",
+  "baseLocale": "en",
+  "locales": ["en", "de", "fr", "es", "it", "pl", "ko", "nl", "pt-BR"],
+  "modules": [
+    "https://cdn.jsdelivr.net/npm/@inlang/plugin-message-format@4.5.5/dist/index.js"
+  ],
+  "plugin.inlang.messageFormat": {
+    "pathPattern": "./messages/{locale}.json"
+  }
+}
diff --git a/src/__tests__/inlang-project-settings.test.ts b/src/__tests__/inlang-project-settings.test.ts
new file mode 100644
index 000000000..eaa805da6
--- /dev/null
+++ b/src/__tests__/inlang-project-settings.test.ts
@@ -0,0 +1,48 @@
+/**
+ * The inlang project that the Fink browser editor opens.
+ *
+ * `project.inlang/settings.json` names the locales Fink offers and the files it
+ * writes. A locale added to the i18n config but not here never shows
+ * up in the editor, and one listed here but not shipped would invite
+ * translations of a bundle the app never loads. The plugin is pinned to an
+ * exact version: it decides how the nested JSON is written back, and the
+ * round trip was verified against that version only (an unpinned URL would
+ * pick up a new serialiser on its own).
+ */
+import { readFileSync } from "node:fs";
+import { join } from "node:path";
+
+import { describe, expect, it } from "vitest";
+
+import { defaultLocale, locales } from "@/lib/i18n/config";
+
+const SETTINGS = join(__dirname, "../../project.inlang/settings.json");
+
+interface InlangSettings {
+  baseLocale: string;
+  locales: string[];
+  modules: string[];
+  "plugin.inlang.messageFormat"?: { pathPattern?: string };
+}
+
+const settings = JSON.parse(readFileSync(SETTINGS, "utf8")) as InlangSettings;
+
+describe("inlang project settings", () => {
+  it("offers exactly the shipped locales, English as the source", () => {
+    expect(settings.baseLocale).toBe(defaultLocale);
+    expect([...settings.locales].sort()).toEqual([...locales].sort());
+  });
+
+  it("points the message-format plugin at the catalogues", () => {
+    expect(settings["plugin.inlang.messageFormat"]?.pathPattern).toBe(
+      "./messages/{locale}.json",
+    );
+  });
+
+  it("pins the one plugin to an exact version", () => {
+    expect(settings.modules).toHaveLength(1);
+    expect(settings.modules[0]).toMatch(
+      /^https:\/\/cdn\.jsdelivr\.net\/npm\/@inlang\/plugin-message-format@\d+\.\d+\.\d+\/dist\/index\.js$/,
+    );
+  });
+});