MCP サーバーであり、ytmusicapi をラップして、Claude（または任意の MCP クライアント）が YouTube Music の検索、プレイリストの管理、リスニング履歴の読み取りを行えるようにします。
ツール | 説明 |
| YouTube Music を検索します。 |
| ライブラリのプレイリストを一覧表示します。 |
| プレイリスト内のトラックを取得します。 |
| 新しいプライベートプレイリストを作成し、その ID を返します。 |
| トラックをプレイリストに追加します。 |
| 最近の再生履歴を取得します。 |
含まれていません（v1）： BPM ベースのレコメンデーション。YouTube Music はテンポデータを公開していないため、これには別のデータソース（例：オーディオ分析 API）が必要になります。これは将来のバージョンでのストレッチゴールであり、今回のビルドには含まれていません。
Related MCP server: mcp-server-youtube
python3 -m venv .venv
source .venv/bin/activate
pip install -e .公式の YouTube Music API は存在しないため、ytmusicapi はログイン済みのブラウザセッションのヘッダーを再利用して認証を行います。
ログインした状態で Firefox（推奨 – 生ヘッダーのコピーが Chrome よりも信頼性が高い）で music.youtube.com を開きます。
DevTools（Cmd+Option+I / F12）→ Network タブ → browse でフィルタリングします。
プレイリストをクリックするか、ページをリロードして、browse POST リクエストをトリガーします。
そのリクエストをクリック → Headers タブ → Raw headers に切り替え → ブロック全体を選択してコピーします。
それをプロジェクトルートに raw_headers.txt という名前の新しいファイルに貼り付けて保存します。
以下を実行します：
python scripts/setup_auth_from_file.pyこれにより、headers_auth.json が書き込まれ、raw_headers.txt が削除されます。
または、python scripts/setup_auth.py は、ファイルの代わりにインタラクティブなターミナルプロンプトを介して同じことを行います（直接貼り付けたい場合に便利です）。
headers_auth.json はログイン済みセッションと同等です – これをコミットしたり共有したりしないでください。 すでに gitignore されています。
先に進む前に認証が機能することを確認してください：
python scripts/test_search.pyこれらのヘッダーは定期的に期限切れ/ローテーションします。認証エラーでツールが失敗し始めた場合は、この手順をやり直してください。
claude mcp add ytmusic -s user \
-e YTMUSIC_AUTH_PATH="$(pwd)/headers_auth.json" \
-- "$(pwd)/.venv/bin/python" "$(pwd)/server.py"-s user を指定すると、このディレクトリだけでなく、任意の Claude Code セッションで使用できるようになります。サーバーは任意の作業ディレクトリから起動できるため、python インタプリタ、server.py、YTMUSIC_AUTH_PATH には絶対パスを使用してください。
他の MCP クライアント（Claude Desktop など）の場合は、それぞれの設定形式を使用して、同じコマンドと環境変数を指定します。
ツールコールは、一般的な障害モードを生のトレースバックではなく、明確なメッセージに変換します：
認証情報の欠落/期限切れ/不正 → scripts/setup_auth_from_file.py を再実行するように指示します。
レート制限（HTTP 429） → 待ってから再試行するように指示します。
ゲート/制限付きコンテンツ → クラッシュする代わりに利用不可として報告します。
ネットワークエラー → 直接報告します。
MIT – LICENSE を参照してください。
Add a track to a playlist by video ID.
| Name | Required | Description | Default |
|---|---|---|---|
| video_id | Yes | ||
| playlist_id | Yes |
| Name | Required | Description |
|---|---|---|
| result | Yes |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must disclose behavioral traits. It indicates a mutation (add) but omits critical details: idempotency, duplicate handling, error conditions (e.g., playlist not found), access requirements, or side effects. This is insufficient for safe agent invocation.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single sentence, which is concise. However, conciseness comes at the cost of completeness; a slightly longer description including a prerequisite or behavioral note would improve utility without being verbose.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool's complexity (mutation, two required params, no annotations, sibling tools), the description is insufficiently complete. It fails to cover execution context (e.g., playlist existence, authentication) and does not leverage the presence of an output schema to reduce burden. Significant gaps remain.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 0%, so the description must compensate. It adds minimal meaning by stating 'by video ID' (hinting that video_id is the identifier) but does not explain the format, constraints, or how to obtain valid values. No additional context for playlist_id.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the action (add a track to a playlist) and the key identifier (by video ID). It distinguishes the tool from siblings like create_playlist (creation) and get_playlists (listing). However, it does not specify prerequisites such as playlist ownership or authentication, which slightly weakens clarity.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance is provided on when to use this tool versus alternatives. The sibling tools are listed but not referenced, and there is no mention of cases where another tool (e.g., search_music to find a video_id first) might be needed beforehand.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Create a new private playlist and return its playlist ID.
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | ||
| description | No |
| Name | Required | Description |
|---|---|---|
| result | Yes |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description must fully disclose behavioral traits. It states the tool creates a playlist and returns an ID, but omits important details: whether overwriting occurs for duplicate names, what happens on failure, authorization requirements, or if the playlist is truly private by default. The description leaves significant gaps for a mutation tool.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single sentence of 9 words, front-loading the key action and output. It is concise and to the point, though it sacrifices some necessary detail. No filler or redundancy.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given 0% schema description coverage and no annotations, the description is far from complete. It does not explain return value contents beyond 'playlist ID' (output schema exists but description doesn't reference it), error cases, or side effects. For a tool creating a resource, this is insufficient.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 0%, meaning the description adds no meaning to the two parameters—'name' and 'description' are listed but not explained. The description does not mention that 'name' is required or provide any guidance on format, length, or uniqueness. The baseline would be higher with good schema docs, but here description totally fails to compensate.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the action ('Create'), the resource ('a new private playlist'), and the result ('return its playlist ID'). It distinguishes itself from siblings like add_to_playlist or search_music, but does not specify the playlist is private by default or that the name is required—though that is implied by the schema.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
No explicit guidance is given on when to use this tool versus alternatives like get_playlists or add_to_playlist. It does not state prerequisites (e.g., must have account, must not exceed playlist limit) or when not to use it. The context of 'private' is a hint but insufficient for decision-making around usage.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Get recent play history.
| Name | Required | Description | Default |
|---|---|---|---|
No parameters | |||
| Name | Required | Description |
|---|---|---|
| result | Yes |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure. It only implies a read operation with a temporal filter ('recent'), but does not disclose side effects, authentication needs, rate limits, or pagination behavior. The single sentence leaves many important behavioral gaps.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single, front-loaded imperative sentence: 'Get recent play history.' It is concise with no wasted words. While it could benefit from slightly more detail, it is not overly sparse to the point of being cryptic. It earns its place by clearly stating the tool's primary action.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given that there are no parameters and an output schema exists to describe return values, the description is minimally acceptable. However, it lacks completeness regarding the definition of 'recent', any implicit limits, and how the results are ordered. The agent may still need to infer these details from the output schema, leaving some uncertainty.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The input schema has 0 parameters and schema_description_coverage is 100% (trivially). According to the rubric, 0 parameters sets a baseline of 4. The description cannot add parameter meaning beyond the schema, but it does not need to because there are none. This score is appropriate.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the verb 'Get' and the resource 'recent play history'. It distinguishes the tool from siblings like search_music and get_playlists, as none of them deal with history. However, the description could be more specific about the type of history (e.g., playback, search) and the scope of 'recent'.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides no guidance on when to use this tool vs its siblings. There is no mention of use cases, exclusions, or alternatives. The agent receives no contextual hints about selecting this tool over other retrieval or search tools.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
List your YouTube Music library playlists.
| Name | Required | Description | Default |
|---|---|---|---|
No parameters | |||
| Name | Required | Description |
|---|---|---|
| result | Yes |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure. It only states 'List your YouTube Music library playlists', which is a minimal read operation. It does not mention authentication requirements, whether the list is paginated, or what happens if the library is empty. More transparency is needed for a tool with zero annotation coverage.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single, front-loaded sentence of four words: 'List your YouTube Music library playlists.' Every word is meaningful, and there is no redundancy or wasted space. It is optimally concise.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool's simplicity (zero parameters) and the presence of an output schema, the description is largely complete. It conveys the core action and scope. However, it could slightly improve by explicitly stating that it returns all playlists for the authenticated user, but this is not a critical gap.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The input schema has zero parameters, so schema coverage is effectively 100%. The description adds no parameter semantics (none needed). Baseline 3 applies as the description does not require additional parameter information, but it also does not add value beyond the schema.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description uses a specific verb ('List') and resource ('your YouTube Music library playlists'), clearly distinguishing from siblings like 'create_playlist' or 'search_music'. It is unambiguous and directly states the tool's function.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description implies the tool is for retrieving all playlists, but it offers no explicit guidance on when to use this versus alternatives like 'get_playlist_tracks' (for a specific playlist's tracks) or 'search_music' (for searching beyond playlists). The purpose is clear, but the usage context is left inferred.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Get the tracks in a playlist.
| Name | Required | Description | Default |
|---|---|---|---|
| playlist_id | Yes |
| Name | Required | Description |
|---|---|---|
| result | Yes |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description must disclose behavioral traits. It fails to mention whether the operation is read-only (likely), if authentication is required, or how it behaves with empty/paginated playlists. The one-line description does not add behavioral depth.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is very concise at one sentence. However, it could be slightly expanded to be more informative without losing brevity. As is, it is not verbose, but 'earns its place' only minimally.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given there is an output schema (providing some structure for results) and a single required parameter, the description still lacks completeness. It does not mention that the result likely includes track details, any sorting, or limits. For such a simple tool, the info gap is moderate.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 0%, so the description needs to compensate. However, it adds no meaning to the playlist_id parameter—no format, ownership context, or example. Given the small parameter count and that the schema provides a title, the description does not significantly enhance understanding.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the action ('get') and the resource ('tracks in a playlist'). Although the name is somewhat self-explanatory, the description provides clarity without being vague. It distinguishes this tool from siblings like search_music or create_playlist, but does not explicitly highlight the distinction.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
There is no guidance on when to use this tool versus alternatives like search_music (which might return tracks based on criteria) or get_playlists. No context is given about prerequisites (e.g., does the playlist need to exist?) or limitations.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Search YouTube Music.
filter: one of songs, videos, albums, artists, playlists, community_playlists, featured_playlists, profiles, podcasts, episodes. Omit for a mixed search. Returns an empty list if there are no matches.
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | ||
| query | Yes | ||
| filter | No |
| Name | Required | Description |
|---|---|---|
| result | Yes |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden of behavioral disclosure. It states 'Returns an empty list if there are no matches,' which is useful. However, it does not mention whether the operation is read-only, any rate limits, or side effects. For a search tool, read-only is implied but not confirmed.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is concise at two sentences plus a list of filter values. It front-loads the main action. However, the filter options are presented as a run-on sentence, which could be clearer with better formatting (e.g., bullet points). Still, it is efficient and avoids unnecessary words.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool has 3 parameters, no schema descriptions, no annotations, and an output schema (not shown), the description covers the filter parameter and the empty return case. It does not explain the 'limit' parameter or pagination behavior. The query parameter is obvious. The description is adequate but not complete for a new user.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 0%, so the description must add meaning. It explains the 'filter' parameter in detail, listing valid values and the default behavior. It does not explain 'query' (self-explanatory) or 'limit' (not explained). This partially compensates for the schema gap, but one parameter is left undocumented.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description states 'Search YouTube Music' which is a clear verb+resource combination. It lists filter options, adding specificity. However, it does not explicitly distinguish from sibling tools, though the sibling tools are all about playlists and history, making the distinction implicit. The purpose is clear but not fully elaborated.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides guidance on the filter parameter ('Omit for a mixed search') but does not explain when to use this tool versus alternatives like get_playlists or get_history. The intended use case is implied by the name, but no explicit when-to-use or when-not-to-use guidance is given.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
v0.1.0add_to_playlistcreate_playlistget_historyget_playlist_tracksget_playlistssearch_musicScored across 6 tools
Each tool targets a distinct action or resource: search, library playlists, playlist tracks, playlist creation, playlist modification, and history. No two tools have overlapping purposes, making selection unambiguous.
Tool names follow a consistent verb_noun pattern (search_music, get_playlists, get_playlist_tracks, create_playlist, add_to_playlist, get_history). The only minor deviation is 'add_to_playlist' instead of 'add_track_to_playlist', but the pattern is still clear.
With 6 tools, the number is well-scoped for a YouTube Music server that focuses on search, playlist management, and history. Each tool earns its place without being overwhelming or too sparse.
The set covers search, playlist CRUD (create, read tracks, add to), and history, but lacks tools for removing tracks from playlists, updating playlist metadata, or managing likes/ratings. This leaves some common music management workflows incomplete.
YouTube transcripts, search, channel browsing, and playlists for AI agents via MCP.
YouTube transcripts, search, channel/playlist listings and upload tracking for AI agents.
Search YouTube, read video metadata, and fetch transcripts with language preferences
YouTube discovery, transcripts, library search, and monitors with API keys or OAuth.
