diff --git a/.github/workflows/python-tests.yml b/.github/workflows/python-tests.yml
new file mode 100644
index 000000000..f0ce1ad65
--- /dev/null
+++ b/.github/workflows/python-tests.yml
@@ -0,0 +1,33 @@
+# Python packages sit outside the Bun test graph; this runs their pytest suites
+# under uv on change. Only apps/bugsink (the Bugsink R2 storage adapter) has one.
+name: Python tests
+
+on:
+  pull_request:
+    paths:
+      - 'apps/bugsink/**'
+      - '.github/workflows/python-tests.yml'
+
+permissions:
+  contents: read
+
+jobs:
+  pytest:
+    name: pytest
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    steps:
+      - name: Checkout
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
+
+      - name: Setup uv
+        uses: astral-sh/setup-uv@11f9893b081a58869d3b5fccaea48c9e9e46f990 # v8.3.2
+
+      - name: Setup Bun
+        uses: oven-sh/setup-bun@0c5077e51419868618aeaa5fe8019c62421857d6 # v2.2.0
+        with:
+          bun-version-file: .bun-version
+
+      - name: Run adapter tests
+        working-directory: apps/bugsink
+        run: bun run test:adapter
diff --git a/.gitignore b/.gitignore
index 8e81ed7a7..976c46c57 100644
--- a/.gitignore
+++ b/.gitignore
@@ -71,4 +71,8 @@ todo.md
 apps/web/src/styled-system/
 libs/design/design-system/src/styled-system/
 libs/design/styled-system/styled-system/
-styled-system-studio
\ No newline at end of file
+styled-system-studio
+# python (apps/bugsink adapter)
+__pycache__/
+*.pyc
+.pytest_cache/
diff --git a/AGENTS.md b/AGENTS.md
index 1b3159f7e..e2a81bf50 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -306,7 +306,7 @@ Screens and routes are built workable-only:
 - `bun install` — whole workspace (`--frozen-lockfile` in CI; `bun.lock` is committed).
 - `bun run typecheck` — `turbo run typecheck`; one project via `--filter=@vers/<name>`.
 - `bun run test` — `turbo run test`, each project's own runner; one project via `--filter`. Every
-  package runs on `bun test` — never add vitest. Postgres-backed suites need
+  JS/TS package runs on `bun test` — never add vitest. Postgres-backed suites need
   `bun run pg:test-container:start` first. bunfig is read from cwd, not merged up, but root-invoked
   `bun test <file>` still resolves jest-extended matchers from the root preload.
 - `bun run lint` / `bun run lint:fix` — `turbo run codegen typegen`, then type-aware oxlint over the
@@ -323,6 +323,8 @@ Screens and routes are built workable-only:
   present; a dependency knip can't see gets a `knip.json` ignore in the PR that introduces it.
 - Git hooks: lefthook (`lefthook.yml`, installed by `prepare`). Pre-push tests changed files only
   (`turbo run test --affected`); `LEFTHOOK=0` skips all hooks.
+- Python (`apps/bugsink` only) runs `pytest` under `uv` via its `test:adapter` script, outside the
+  Bun graph; the `python-tests` workflow runs it on change.
 
 ## Lint policy
 
diff --git a/agents/project.md b/agents/project.md
index 5d3e9c351..2e9132c15 100644
--- a/agents/project.md
+++ b/agents/project.md
@@ -161,7 +161,7 @@ Screens and routes are built workable-only:
 - `bun install` — whole workspace (`--frozen-lockfile` in CI; `bun.lock` is committed).
 - `bun run typecheck` — `turbo run typecheck`; one project via `--filter=@vers/<name>`.
 - `bun run test` — `turbo run test`, each project's own runner; one project via `--filter`. Every
-  package runs on `bun test` — never add vitest. Postgres-backed suites need
+  JS/TS package runs on `bun test` — never add vitest. Postgres-backed suites need
   `bun run pg:test-container:start` first. bunfig is read from cwd, not merged up, but root-invoked
   `bun test <file>` still resolves jest-extended matchers from the root preload.
 - `bun run lint` / `bun run lint:fix` — `turbo run codegen typegen`, then type-aware oxlint over the
@@ -178,6 +178,8 @@ Screens and routes are built workable-only:
   present; a dependency knip can't see gets a `knip.json` ignore in the PR that introduces it.
 - Git hooks: lefthook (`lefthook.yml`, installed by `prepare`). Pre-push tests changed files only
   (`turbo run test --affected`); `LEFTHOOK=0` skips all hooks.
+- Python (`apps/bugsink` only) runs `pytest` under `uv` via its `test:adapter` script, outside the
+  Bun graph; the `python-tests` workflow runs it on change.
 
 ## Lint policy
 
diff --git a/apps/bugsink/README.md b/apps/bugsink/README.md
index d09fff236..34eb07925 100644
--- a/apps/bugsink/README.md
+++ b/apps/bugsink/README.md
@@ -11,6 +11,10 @@ manual roll is `fly deploy --config apps/bugsink/fly.toml`. `bugsink_conf.py` im
 image's config and overrides only the file object storage, so the rest of Bugsink's env-driven
 settings stay upstream's.
 
+The Python here (`r2_storage.py`) sits outside the Bun test graph, so `@vers/bugsink` carries a
+`test:adapter` script that runs its pytest suite (moto-mocked S3) under `uv`, and the `python-tests`
+workflow runs it on changes to this directory.
+
 ## Storage
 
 Event data lives in a dedicated database in the shared Neon project (`DATABASE_URL` secret) — no app
diff --git a/apps/bugsink/package.json b/apps/bugsink/package.json
new file mode 100644
index 000000000..85dc07106
--- /dev/null
+++ b/apps/bugsink/package.json
@@ -0,0 +1,9 @@
+{
+  "name": "@vers/bugsink",
+  "version": "0.0.0",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "test:adapter": "uv run --with boto3==1.43.46 --with moto --with pytest pytest r2_storage_test.py"
+  }
+}
diff --git a/apps/bugsink/r2_storage_test.py b/apps/bugsink/r2_storage_test.py
new file mode 100644
index 000000000..f779c6545
--- /dev/null
+++ b/apps/bugsink/r2_storage_test.py
@@ -0,0 +1,75 @@
+"""
+Adapter tests for r2_storage against a mocked S3 (moto). Bugsink's ObjectStorage
+base is stubbed here — the real one only raises NotImplementedError — so the
+adapter imports without installing Bugsink; these exercise the concrete R2/S3
+behaviour, which is the part that can break.
+"""
+
+import os
+import sys
+import types
+
+import boto3
+import pytest
+from moto import mock_aws
+
+_storage = types.ModuleType("files.storage")
+
+
+class ObjectStorage:
+    def __init__(self, name, object_kind, **options):
+        self.name = name
+        self.object_kind = object_kind
+
+
+_storage.ObjectStorage = ObjectStorage
+sys.modules.setdefault("files", types.ModuleType("files"))
+sys.modules["files.storage"] = _storage
+
+os.environ.setdefault("R2_ENDPOINT_URL", "https://s3.amazonaws.com")
+os.environ.setdefault("R2_BUCKET", "test-bucket")
+os.environ.setdefault("R2_ACCESS_KEY_ID", "test-key")
+os.environ.setdefault("R2_SECRET_ACCESS_KEY", "test-secret")
+
+import r2_storage  # noqa: E402
+
+
+@pytest.fixture
+def storage():
+    with mock_aws():
+        boto3.client("s3", region_name="us-east-1").create_bucket(Bucket="test-bucket")
+        yield r2_storage.R2ObjectStorage("r2", object_kind="file")
+
+
+def test_write_then_read_roundtrips(storage):
+    with storage.open("bundle/app.js.map", "wb") as f:
+        f.write(b"sourcemap-bytes")
+    with storage.open("bundle/app.js.map", "rb") as f:
+        assert f.read() == b"sourcemap-bytes"
+
+
+def test_exists_reflects_presence(storage):
+    assert storage.exists("bundle/app.js.map") is False
+    with storage.open("bundle/app.js.map", "wb") as f:
+        f.write(b"x")
+    assert storage.exists("bundle/app.js.map") is True
+
+
+def test_list_yields_written_keys(storage):
+    for key in ("a", "b/c"):
+        with storage.open(key, "wb") as f:
+            f.write(b"x")
+    assert set(storage.list()) == {"a", "b/c"}
+
+
+def test_delete_removes_the_object(storage):
+    with storage.open("gone", "wb") as f:
+        f.write(b"x")
+    storage.delete("gone")
+    assert storage.exists("gone") is False
+
+
+def test_open_rejects_unknown_mode(storage):
+    with pytest.raises(ValueError):
+        with storage.open("k", "ab"):
+            pass
diff --git a/apps/bugsink/turbo.json b/apps/bugsink/turbo.json
new file mode 100644
index 000000000..5917af972
--- /dev/null
+++ b/apps/bugsink/turbo.json
@@ -0,0 +1,4 @@
+{
+  "extends": ["//"],
+  "tags": ["app"]
+}
diff --git a/bun.lock b/bun.lock
index a337e4b23..21f5c2e71 100644
--- a/bun.lock
+++ b/bun.lock
@@ -28,6 +28,10 @@
         "zod": "catalog:",
       },
     },
+    "apps/bugsink": {
+      "name": "@vers/bugsink",
+      "version": "0.0.0",
+    },
     "apps/web": {
       "name": "@vers/web",
       "version": "0.0.0",
@@ -2198,6 +2202,8 @@
 
     "@ver0/deep-equal": ["@ver0/deep-equal@1.0.1", "", {}, "sha512-XSvL5wKXBZIv7fflMqhQx936sRpEtzxeV25xAEt0rLLXzbF6RCQaRA1jrVIn8JCubMyn/y0TaidphUtilLzl1A=="],
 
+    "@vers/bugsink": ["@vers/bugsink@workspace:apps/bugsink"],
+
     "@vers/client-test-utils": ["@vers/client-test-utils@workspace:libs/testing/client-test-utils"],
 
     "@vers/contract-activity": ["@vers/contract-activity@workspace:contracts/activity"],
diff --git a/knip.json b/knip.json
index 95dad3bf1..6d0241d00 100644
--- a/knip.json
+++ b/knip.json
@@ -6,7 +6,7 @@
     "libs/game/worldmap-core/generate-graph.ts",
     ".claude/**"
   ],
-  "ignoreBinaries": ["flyctl", "gh", "ladle", "op", "pulumi"],
+  "ignoreBinaries": ["flyctl", "gh", "ladle", "op", "pulumi", "uv"],
   "rules": {
     "enumMembers": "off"
   },