diff --git a/.claude/skills/add-problem/SKILL.md b/.claude/skills/add-problem/SKILL.md
index f8caef0..0a23e69 100644
--- a/.claude/skills/add-problem/SKILL.md
+++ b/.claude/skills/add-problem/SKILL.md
@@ -54,38 +54,15 @@ description: vimro の問題 JSON を作成する。カテゴリ・狙う操作
 
 ## 検証（必須）
 
-スクラッチパッドに一時スクリプトを作り、headless で実行する:
-
-```lua
--- verify.lua（スクラッチパッドに置く。REPO と FILE を差し替える）
-local root = "REPO"  -- リポジトリ絶対パス
-vim.opt.rtp:prepend(root)
-local p = vim.json.decode(table.concat(vim.fn.readfile(root .. "/problems/FILE"), "\n"))
-for i, s in ipairs(p.solutions) do
-  local buf = vim.api.nvim_create_buf(false, true)
-  vim.api.nvim_set_current_buf(buf)
-  vim.api.nvim_buf_set_lines(buf, 0, -1, false, p.start)
-  vim.api.nvim_win_set_cursor(0, { 1, 0 })
-  vim.api.nvim_feedkeys(vim.api.nvim_replace_termcodes(s.keys, true, false, true), "x", false)
-  vim.api.nvim_feedkeys(vim.api.nvim_replace_termcodes("<Esc>", true, false, true), "x", false)
-  local got = vim.api.nvim_buf_get_lines(buf, 0, -1, false)
-  assert(require("vimro.engine").is_cleared(got, p.goal),
-    ("solution %d (%s) failed: %s"):format(i, s.keys, vim.inspect(got)))
-end
-print("OK")
-```
+リポジトリルートで実行する。solutions の再生とスキーマを機械確認する（CI でも同じものが走るが、壊れた PR を出さないためにローカルで先に通す）:
 
 ```sh
-nvim --headless -u NONE -l verify.lua
+nvim --headless -u NONE -l scripts/verify_problems.lua
 ```
 
-これで **全 solutions の keys が start を goal に本当に変形するか**を機械確認する。失敗したら `start` / `goal` / `keys` を見直す。
-
-あわせて次も目視確認する:
+失敗すると該当 `id` と実際に生成されたバッファ内容が出るので、`start` / `goal` / `keys` を見直す。
 
-- `notes` の要素数が `solutions` と一致しているか（ja / en 両方）
-- `id` の重複がないか（`grep -r '"id"' problems/<category>/`）
-- `description` と `goal` が矛盾していないか
+これに加えて **`description` と `goal` が矛盾していないか**だけは目視で確認する（機械検証できない唯一の項目）。
 
 ## PR の作成
 
@@ -103,12 +80,11 @@ gh pr create --base main --label problems \
 ## Summary
 - 追加した問題と狙う操作を1〜2行で
 
-## Verification
-- headless Neovim で全 solutions を再生し goal に到達することを確認
-
 🤖 Generated with [Claude Code](https://claude.com/claude-code)
 EOF
 )"
 ```
 
 `problems` ラベルはリポジトリに作成済みなので `--label problems` をそのまま使う。付与に失敗した場合のみ `gh pr edit <番号> --add-label problems` で追う。作成後は PR の URL をユーザーに伝える。
+
+**ラベルはリリースのバージョンを決める**: main にマージされると `.github/workflows/release.yml` が自動でタグを打ってリリースする。`problems` ラベル（およびラベル無し）は patch、`enhancement` は minor、`breaking` は major。問題追加は patch のままでよいので、通常は `problems` だけ付ければよい。
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..3cd1c16
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,30 @@
+name: CI
+
+on:
+  pull_request:
+    branches: [main]
+  push:
+    branches: [main]
+
+jobs:
+  verify:
+    name: Verify problems
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: rhysd/action-setup-vim@v1
+        with:
+          neovim: true
+          version: stable
+      - run: nvim --headless -u NONE -l scripts/verify_problems.lua
+
+  load:
+    name: Load plugin
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: rhysd/action-setup-vim@v1
+        with:
+          neovim: true
+          version: stable
+      - run: nvim --headless -u NONE -l scripts/load_check.lua
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
new file mode 100644
index 0000000..e0a253a
--- /dev/null
+++ b/.github/workflows/release.yml
@@ -0,0 +1,96 @@
+name: Release
+
+on:
+  push:
+    branches: [main]
+
+permissions:
+  contents: write
+  pull-requests: read
+
+concurrency:
+  group: release
+  cancel-in-progress: false
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - uses: rhysd/action-setup-vim@v1
+        with:
+          neovim: true
+          version: stable
+
+      - name: Verify before releasing
+        run: |
+          nvim --headless -u NONE -l scripts/verify_problems.lua
+          nvim --headless -u NONE -l scripts/load_check.lua
+
+      - name: Skip if this commit is already tagged
+        id: tagged
+        run: |
+          if git tag --points-at HEAD | grep -q '^v'; then
+            echo "skip=true" >> "$GITHUB_OUTPUT"
+          else
+            echo "skip=false" >> "$GITHUB_OUTPUT"
+          fi
+
+      - name: Decide the next version
+        id: version
+        if: steps.tagged.outputs.skip == 'false'
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          set -euo pipefail
+
+          labels=$(gh pr list --state merged --search "$GITHUB_SHA" \
+            --json labels --jq '.[0].labels[].name' 2>/dev/null || true)
+          echo "labels: ${labels:-<none>}"
+
+          bump=patch
+          if grep -qx 'breaking' <<<"$labels"; then
+            bump=major
+          elif grep -qx 'enhancement' <<<"$labels"; then
+            bump=minor
+          fi
+
+          prev=$(git tag --list 'v*' --sort=-v:refname | head -1)
+          prev=${prev:-v0.0.0}
+          IFS=. read -r major minor patch <<<"${prev#v}"
+
+          case "$bump" in
+            major) major=$((major + 1)); minor=0; patch=0 ;;
+            minor) minor=$((minor + 1)); patch=0 ;;
+            patch) patch=$((patch + 1)) ;;
+          esac
+
+          next="v${major}.${minor}.${patch}"
+          echo "$prev -> $next ($bump)"
+          {
+            echo "prev=$prev"
+            echo "next=$next"
+          } >> "$GITHUB_OUTPUT"
+
+      - name: Tag and release
+        if: steps.tagged.outputs.skip == 'false'
+        env:
+          GH_TOKEN: ${{ github.token }}
+          PREV: ${{ steps.version.outputs.prev }}
+          NEXT: ${{ steps.version.outputs.next }}
+        run: |
+          set -euo pipefail
+          git config user.name "github-actions[bot]"
+          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+          git tag -a "$NEXT" -m "$NEXT"
+          git push origin "$NEXT"
+
+          gh api "repos/$GITHUB_REPOSITORY/releases/generate-notes" \
+            -f tag_name="$NEXT" -f previous_tag_name="$PREV" \
+            --jq .body > notes.md
+          ./scripts/problem_delta.sh "$PREV" >> notes.md
+
+          gh release create "$NEXT" --title "$NEXT" --notes-file notes.md
diff --git a/CLAUDE.md b/CLAUDE.md
index e47f4ef..95d7c36 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -16,29 +16,38 @@ Run the plugin from the repo without installing it:
 nvim --cmd "set rtp+=$PWD" +Vimro
 ```
 
-Verify a problem's solutions actually transform `start` into `goal` (headless, no config):
+Verify every problem — schema plus a real headless replay of each solution against `goal`:
 
 ```sh
-nvim --headless -u NONE -l verify.lua   # see .claude/skills/add-problem/SKILL.md for the script
+nvim --headless -u NONE -l scripts/verify_problems.lua
 ```
 
-That headless-replay pattern is the only automated check in the repo — use it whenever problem JSON changes.
+Check that every module still loads:
+
+```sh
+nvim --headless -u NONE -l scripts/load_check.lua
+```
+
+Both run in CI (`.github/workflows/ci.yml`) on every PR and push to main. Run `verify_problems.lua` locally whenever problem JSON changes — a failure prints the offending `id` and the buffer it actually produced.
+
+## Release automation
+
+Merging to `main` releases automatically (`.github/workflows/release.yml`): it re-runs both checks, reads the merged PR's labels to pick the bump (`breaking` → major, `enhancement` → minor, anything else including `problems` → patch), tags `vX.Y.Z` off the latest `v*` tag, and publishes a GitHub release. Notes are GitHub's generated ones plus a problem-count delta from `scripts/problem_delta.sh`. A commit that already carries a `v*` tag is skipped, so re-runs are safe. Tags without the `v` prefix (`1.0.0`, `1.1.0`) are legacy and ignored by the version lookup.
 
 ## Architecture
 
-Five modules, each with one job. `ui.lua` is the only one that knows about the others.
+Four modules, each with one job. `ui.lua` is the only one that knows about the others.
 
 - **`engine.lua`** — no UI, no state beyond the progress file. Loads/sorts problems (difficulty, then id), decides clearing, persists progress. `root()` derives the plugin directory from `debug.getinfo`, so `problems/` is always found relative to the installed plugin, not the cwd.
 - **`ui.lua`** — session state (`S`), the two-window tab layout, keymaps, rendering, startup flow. Everything user-visible lives here.
 - **`config.lua`** — `M.defaults` is the single source of truth for options; `setup()` deep-extends into `M.options`. `ui.lua` reads `config.options` live, so runtime mutation (e.g. the language picker setting `config.options.lang`) takes effect immediately.
 - **`i18n/`** — `t(key, ...)` for UI strings, `resolve_problem()` for per-problem text. Both fall back `lang` → `fallback_lang`; `t()` finally falls back to the key itself, so a missing string degrades rather than errors.
-- **`keys.lua`** — keystroke counter via a single `vim.on_key` handler, counting only while the practice buffer is current.
 
 ### Things that will bite you
 
 - **Clear matching is deliberately loose in one axis only**: `engine.normalize` strips trailing whitespace per line and drops trailing blank lines. Line contents and line count are otherwise strict. Problems whose answer depends on trailing whitespace cannot be expressed.
 - **Keymaps in the practice buffer must stay behind `buffer_prefix`.** Binding plain `n` / `r` there would shadow the exact Vim motions being trained. The problem pane is where bare keys are safe.
-- **Categories are hardcoded in `ui.lua`** (`local categories = { "plain" }`) even though `engine.load_problems` accepts any directory name. Adding a new `problems/<category>/` requires editing that list too.
+- **Categories are auto-detected** by `engine.list_categories()` from the subdirectories of `problems/`, so a new category needs no code change.
 - **Every problem starts at `[1, 1]`.** There is no per-problem start position: getting to the spot you edit is part of the drill, and a mid-line start reads as a leftover cursor from the previous problem. Solutions must therefore include whatever motion they need.
 - **`quit()` has two exit paths**: started from an empty Neovim (`is_fresh_nvim`) it runs `qa` and exits the editor; otherwise it tears down the tab/split and wipes buffers. Both must leave `S` clean, since `M.start()` guards re-entry on `S.active`.
 - Both buffers are `nofile` + `bufhidden=wipe`, and a `BufWipeout` autocmd on the practice buffer ends the session — wiping it from anywhere is a supported way to quit.
diff --git a/README.ja.md b/README.ja.md
index 1c3de32..bfe9db1 100644
--- a/README.ja.md
+++ b/README.ja.md
@@ -118,7 +118,7 @@ require("vimro").setup({
 
 - 言語非依存フィールドを埋める: `id` / `category` / `difficulty` / `start` / `goal` / `solutions`（`keys` は `<Esc>` などの vim 表記で、常に 1 行目 1 文字目から始まる。最短解に `"optimal": true`）/ `tags`
 - `i18n.ja` と `i18n.en` の両方を埋める（`title` / `description` / `hints` / `notes`）。`notes[i]` は `solutions[i]` の説明
-- 各 `solutions[].keys` が本当に `start` を `goal` に変形することを Neovim で確認する
+- `nvim --headless -u NONE -l scripts/verify_problems.lua` で検証する。全 `solutions[].keys` を実際に再生し、スキーマも合わせて確認する（同じスクリプトが CI でも走る）
 - 1 問につき狙う操作は 1 つに絞り、`description` と `goal` を必ず一致させる
 
 完全な例は `problems/plain/001-delete-word.json` を参照してください。
diff --git a/README.md b/README.md
index d1f8984..36ae3a9 100644
--- a/README.md
+++ b/README.md
@@ -118,7 +118,7 @@ Problems live in `problems/<category>/NNN-<slug>.json`, one file per problem:
 
 - Fill the language-independent fields: `id`, `category`, `difficulty`, `start`, `goal`, `solutions` (`keys` in Vim notation like `<Esc>`, starting from the first character of the buffer, mark the shortest with `"optimal": true`), `tags`.
 - Fill both `i18n.ja` and `i18n.en` (`title`, `description`, `hints`, `notes`). `notes[i]` describes `solutions[i]`.
-- Verify in Neovim that each `solutions[].keys` really transforms `start` into `goal`.
+- Verify with `nvim --headless -u NONE -l scripts/verify_problems.lua`, which replays every `solutions[].keys` and checks the schema. The same script runs in CI on every pull request.
 - Aim for one target operation per problem, and keep `description` consistent with `goal`.
 
 See `problems/plain/001-delete-word.json` for a complete example.
diff --git a/scripts/load_check.lua b/scripts/load_check.lua
new file mode 100644
index 0000000..b2b9b54
--- /dev/null
+++ b/scripts/load_check.lua
@@ -0,0 +1,31 @@
+-- Require every module under lua/vimro/ so syntax and load-time errors surface.
+--
+--   nvim --headless -u NONE -l scripts/load_check.lua
+
+local root = vim.fn.fnamemodify(debug.getinfo(1, "S").source:sub(2), ":h:h")
+vim.opt.rtp:prepend(root)
+
+local files = vim.fn.glob(root .. "/lua/vimro/**/*.lua", false, true)
+table.sort(files)
+
+local failed = false
+for _, file in ipairs(files) do
+  local mod = file:sub(#root + #"/lua/" + 1):gsub("%.lua$", ""):gsub("/init$", ""):gsub("/", ".")
+  local ok, err = pcall(require, mod)
+  if not ok then
+    failed = true
+    io.stderr:write(("%s: %s\n"):format(mod, err))
+  end
+end
+
+-- plugin/ scripts are sourced by Neovim, not required
+local ok, err = pcall(vim.cmd, "source " .. root .. "/plugin/vimro.lua")
+if not ok then
+  failed = true
+  io.stderr:write("plugin/vimro.lua: " .. tostring(err) .. "\n")
+end
+
+if failed then
+  vim.cmd("cq")
+end
+io.stdout:write(("OK - %d modules loaded\n"):format(#files))
diff --git a/scripts/problem_delta.sh b/scripts/problem_delta.sh
new file mode 100755
index 0000000..2758ed7
--- /dev/null
+++ b/scripts/problem_delta.sh
@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+# Summarize problems added between a previous ref and HEAD, for release notes.
+#
+#   scripts/problem_delta.sh v1.2.1
+#
+# Prints nothing when no problems were added.
+set -euo pipefail
+
+prev="${1:-}"
+[ -n "$prev" ] || exit 0
+
+added=$(git diff --diff-filter=A --name-only "$prev" HEAD -- 'problems/*/*.json' || true)
+[ -n "$added" ] || exit 0
+
+count=$(printf '%s\n' "$added" | wc -l | tr -d ' ')
+by_category=$(printf '%s\n' "$added" | cut -d/ -f2 | sort | uniq -c |
+  awk '{ printf "%s%s: %s", sep, $2, $1; sep = ", " }')
+total=$(git ls-files 'problems/*/*.json' | wc -l | tr -d ' ')
+
+printf '\n## Problems\n\n+%s problems (%s) — %s total\n' "$count" "$by_category" "$total"
diff --git a/scripts/verify_problems.lua b/scripts/verify_problems.lua
new file mode 100644
index 0000000..efdb55e
--- /dev/null
+++ b/scripts/verify_problems.lua
@@ -0,0 +1,135 @@
+-- Verify every problem in problems/: schema, and that each solution really
+-- transforms `start` into `goal` when replayed in a scratch buffer.
+--
+--   nvim --headless -u NONE -l scripts/verify_problems.lua
+
+local root = vim.fn.fnamemodify(debug.getinfo(1, "S").source:sub(2), ":h:h")
+vim.opt.rtp:prepend(root)
+
+local engine = require("vimro.engine")
+
+local errors = {}
+local seen_ids = {}
+local counts = {}
+local total = 0
+
+local function fail(where, msg)
+  table.insert(errors, where .. ": " .. msg)
+end
+
+local function check_schema(file, p)
+  local name = vim.fn.fnamemodify(file, ":t")
+  local category = vim.fn.fnamemodify(file, ":h:t")
+
+  if type(p.id) ~= "string" or not p.id:match("^" .. category .. "%-%d%d%d$") then
+    fail(name, ("id %s does not match <%s>-NNN"):format(vim.inspect(p.id), category))
+    return
+  end
+  if seen_ids[p.id] then
+    fail(name, ("duplicate id %s (also in %s)"):format(p.id, seen_ids[p.id]))
+  end
+  seen_ids[p.id] = name
+
+  if type(p.difficulty) ~= "number" or p.difficulty % 1 ~= 0 or p.difficulty < 1 or p.difficulty > 3 then
+    fail(p.id, "difficulty must be an integer 1-3, got " .. vim.inspect(p.difficulty))
+  end
+  for _, field in ipairs({ "start", "goal", "solutions" }) do
+    if type(p[field]) ~= "table" or vim.tbl_isempty(p[field]) then
+      fail(p.id, field .. " must be a non-empty array")
+    end
+  end
+  if type(p.solutions) ~= "table" then
+    return
+  end
+
+  local optimal = 0
+  for i, s in ipairs(p.solutions) do
+    if type(s.keys) ~= "string" or s.keys == "" then
+      fail(p.id, ("solutions[%d].keys must be a non-empty string"):format(i))
+    end
+    if s.optimal == true then
+      optimal = optimal + 1
+    end
+  end
+  if optimal ~= 1 then
+    fail(p.id, ("exactly one solution must be optimal, found %d"):format(optimal))
+  end
+
+  for _, lang in ipairs({ "ja", "en" }) do
+    local tr = p.i18n and p.i18n[lang]
+    if type(tr) ~= "table" then
+      fail(p.id, "missing i18n." .. lang)
+    else
+      for _, field in ipairs({ "title", "description" }) do
+        if type(tr[field]) ~= "string" or tr[field] == "" then
+          fail(p.id, ("i18n.%s.%s must be a non-empty string"):format(lang, field))
+        end
+      end
+      if type(tr.hints) ~= "table" or vim.tbl_isempty(tr.hints) then
+        fail(p.id, ("i18n.%s.hints must be a non-empty array"):format(lang))
+      end
+      if type(tr.notes) ~= "table" then
+        fail(p.id, ("i18n.%s.notes must be an array"):format(lang))
+      elseif #tr.notes ~= #p.solutions then
+        fail(p.id, ("i18n.%s.notes has %d entries but there are %d solutions"):format(lang, #tr.notes, #p.solutions))
+      end
+    end
+  end
+end
+
+local function check_solutions(p)
+  if type(p.start) ~= "table" or type(p.goal) ~= "table" or type(p.solutions) ~= "table" then
+    return
+  end
+  for i, s in ipairs(p.solutions) do
+    if type(s.keys) == "string" then
+      local buf = vim.api.nvim_create_buf(false, true)
+      vim.api.nvim_set_current_buf(buf)
+      vim.api.nvim_buf_set_lines(buf, 0, -1, false, p.start)
+      vim.api.nvim_win_set_cursor(0, { 1, 0 })
+      local ok, err = pcall(function()
+        vim.api.nvim_feedkeys(vim.api.nvim_replace_termcodes(s.keys, true, false, true), "x", false)
+        vim.api.nvim_feedkeys(vim.api.nvim_replace_termcodes("<Esc>", true, false, true), "x", false)
+      end)
+      if not ok then
+        fail(p.id, ("solution %d (%s) errored: %s"):format(i, s.keys, err))
+      else
+        local got = vim.api.nvim_buf_get_lines(buf, 0, -1, false)
+        if not engine.is_cleared(got, p.goal) then
+          fail(p.id, ("solution %d (%s) produced %s, want %s"):format(i, s.keys, vim.inspect(got), vim.inspect(p.goal)))
+        end
+      end
+      vim.api.nvim_buf_delete(buf, { force = true })
+    end
+  end
+end
+
+for _, category in ipairs(engine.list_categories()) do
+  local files = vim.fn.glob(root .. "/problems/" .. category .. "/*.json", false, true)
+  table.sort(files)
+  counts[category] = #files
+  for _, file in ipairs(files) do
+    total = total + 1
+    local ok, p = pcall(vim.json.decode, table.concat(vim.fn.readfile(file), "\n"))
+    if not ok or type(p) ~= "table" then
+      fail(vim.fn.fnamemodify(file, ":t"), "invalid JSON: " .. tostring(p))
+    else
+      check_schema(file, p)
+      check_solutions(p)
+    end
+  end
+end
+
+if #errors > 0 then
+  io.stderr:write(("%d problem(s) failed verification:\n"):format(#errors))
+  for _, e in ipairs(errors) do
+    io.stderr:write("  " .. e .. "\n")
+  end
+  vim.cmd("cq")
+end
+
+local parts = {}
+for _, category in ipairs(engine.list_categories()) do
+  table.insert(parts, ("%s: %d"):format(category, counts[category]))
+end
+io.stdout:write(("OK - %d problems verified (%s)\n"):format(total, table.concat(parts, ", ")))