Cesure
REMOTE · API.CESURE.APP
Write, edit, transpose and play guitar tabs and staff notation in Cesure.
Available components
Last scanned (20 hours ago)
Scores higher than 55% of remote servers
Reachable. Last reached 24 Oct 2026.
Category Entertainment and Games
How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. How we score → Why this is hard to score →
Endpoint Security66
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- Authorisation check failed: no authorisation is required to call this server, and it exposes a tool marked destructive (edit_measures). See how to fix → View diagnostics → Fail
- HTTPS is enforced; there's no plaintext access path. View diagnostics → Pass
- The HSTS (Strict-Transport-Security) header is present. View diagnostics → Pass
- DNSSEC is configured correctly; the domain's records validate against the full chain to the root. View diagnostics → Pass
Transport & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability36
- 0% of prompts and resources have a non-trivial description (not blank, and not just the item's name).Fail
- AI-judged instruction clarity (good).Pass
- Context-footprint check failed: tool/resource definitions use about 3669 tokens (~244/item across 15 items; 14 tools + 1 resources), over budget; trim descriptions and params. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management40
- Stability observed for 12 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
- Structured output schemas are declared (100% of tools); any adoption earns full credit.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 14 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 16 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
- Supports UI / widget rendering.Pass
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 22 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 30 to 33. That category is still filling its 30-day observation window: 9 days of observed history at the previous scan, 10 at this one. The score rises as the window fills, whether or not the server changes.
- 20 Oct 26 +1
- Resource “cesure_player” now points somewhere else: ui://cesure/player-0.7.0+bb4e383 → ui://cesure/player-0.8.1+530f487 security
- Tool “edit_measures” rewrote its description, which is the text the model reads security
- Tool “import_score” rewrote its description, which is the text the model reads security
- Tool “search_catalog” rewrote its description, which is the text the model reads security
- 19 Oct 26 0
- Resource “cesure_player” now points somewhere else: ui://cesure/player-0.7.0+d2663ee → ui://cesure/player-0.7.0+bb4e383 security
- 18 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 17 to 20. That category is still filling its 30-day observation window: 5 days of observed history at the previous scan, 6 at this one. The score rises as the window fills, whether or not the server changes.
- 16 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 10 to 13. That category is still filling its 30-day observation window: 3 days of observed history at the previous scan, 4 at this one. The score rises as the window fills, whether or not the server changes.
- 14 Oct 26 +1
- Resource “cesure_player” now points somewhere else: ui://cesure/player-0.7.0+ddf0361 → ui://cesure/player-0.7.0+d2663ee security
- The server rewrote its instructions, which are the text every model session reads security
- Tool “create_score” rewrote its description, which is the text the model reads security
- Tool “edit_measures” rewrote its description, which is the text the model reads security
- Tool “list_my_scores” rewrote its description, which is the text the model reads security
- Tool “open_in_cesure” rewrote its description, which is the text the model reads security
- Tool “organize_my_scores” rewrote its description, which is the text the model reads security
- Tool “transpose” rewrote its description, which is the text the model reads security
- “transpose” added an optional parameter “harmonicsOffTheNeck” cosmetic
- “transpose” added an optional parameter “notesOffTheNeck” cosmetic
- 13 Oct 26 0
- Stability: unverified → 0.03 ▲ functional
- 12 Oct 26 61
First indexed and scored.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 24 Oct 2026 · Probed https://api.cesure.app/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=api.cesure.app | CN=YR1,O=Let's Encrypt,C=US | 4 Oct 2026 | 2 Jan 2027 | RSA 4096 | SHA256-RSA | 5e8e916a1e34e23cd833dd47fc804a1d7c2 |
| SANs: api.cesure.app | ||||||
| CN=YR1,O=Let's Encrypt,C=US (CA) | CN=Root YR,O=ISRG,C=US | 3 Sept 2025 | 2 Sept 2028 | RSA 2048 | SHA256-RSA | a20253f15f2691c05dc1ce13b9bcca4e |
| CN=Root YR,O=ISRG,C=US (CA) | CN=ISRG Root X1,O=Internet Security Research Group,C=US | 13 May 2026 | 2 Sept 2032 | RSA 4096 | SHA256-RSA | f24b6d17f9d9ad7cb1c9fea78782699f |
Background: What to check on a remote MCP endpoint →
DNSSEC secure
Validation of api.cesure.app. — Secure
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| app. | present | 23684 | 8 | Verified |
| cesure.app. | present | 407 | 8 | Verified |
| api.cesure.app. | Verified address RRset verified with the apex keys |
Authentication No authorisation required
The endpoint answered without asking for a token. Anyone who knows the URL can reach it.
| Result | No authorisation required |
|---|---|
| HTTP status | 200 |
| Header | Value |
|---|---|
| strict-transport-security | max-age=63072000; includeSubDomains; preload |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://api.cesure.app/mcp | Verified | 200 | |
| http (plaintext) | http://api.cesure.app/mcp | HTTPS enforced | 301 | https://api.cesure.app/mcp |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
create_score Create a score ~823
Create a score you write as a .cesure and open it as a draft, e.g. {"version":2,"score":{"title":"Song","tempo":96,"tracks":[{"name":"Guitar","instrument":"GUITAR","measures":[{"staves":[{"voices":["(0.6 2.5 2.4).2 r.2"]}]}]},{"name":"Bass","instrument":"BASS","tuning":[{"note":"G","octave":2},{"note":"D","octave":2},{"note":"A","octave":1},{"note":"E","octave":1}],"measures":[{"staves":[{"voices":["0.4.2 r.2"]}]}]}]}} (a track without tuning is a guitar in standard tuning; tuning lists the open strings from string 1). Every measure must read and fill its time signature, or nothing is created and the refusal names each fault with its place. Measure notation (.cesure): each voice is one string of beats separated by spaces. beat = content.duration[{d | tu 3}]; content = fret.string[{note props}] | pitch | (note note …) | r. Durations, on EVERY beat: 1 whole, 2 half, 4 quarter, 8, 16, 32, 64. Strings from 1 (the highest); x as fret mutes. A pitch (C4 = middle C, F#3, Bb2) lets Cesure choose string and fret; a staff is all by pitch or all fret.string. Beat props: d dotted, tu 3 triplet on each beat of the group. Note props: t tie, h hammer/pull-off and sl slide to the next note on that string, v vibrato, b (0 4) a whole-tone bend. EACH VOICE FILLS ITS TIME SIGNATURE EXACTLY: 4/4 = 4 quarters = 8 eighths, 3/4 = 3 quarters, 6/8 = 6 eighths; rests complete a short one. A measure without numerator/denominator is 4/4, whatever came before. A second voice (a bass under a melody) is a second string in voices. Examples (4/4): "5.3.4 7.3.4 r.2" (fret 5 then 7 on string 3 (strings from 1, the highest), quarters; a half rest); "(0.1 1.2 0.3).2 x.6.4 r.4" (a chord, a half; a muted note); "E4.8 F#4.8 G4.4 Bb3.2" (notes by pitch (C4 = middle C): Cesure chooses string and fret); "5.3.4{d} 5.3.8 2.1.8{tu 3} 3.1.8{tu 3} 5.1.8{tu 3} 7.2{h}.8 8.2.8" (dotted quarter; a triplet of eighths (each beat carries it); a hammer-on to the next note); "5.3.2 5.3{t}.4 7.2{sl}.8 9.2{v}.8" (a tie to t…
| Name | Type | Req | Description |
|---|---|---|---|
| score | string | yes | The score, a .cesure written in the notation described above. |
Structured output declared, but exposes no named fields.
No examples provided.
edit_measures Edit measures ~950
Rewrite measures from..to (numbers, inclusive) of ONE track of the draft with .cesure measures, as read_score returns them; to = from - 1 inserts before from. A measure written with its id stays that measure, even rewritten; one written without its id is a new measure, and the one it stood for is removed with what it carried (a repeat it opened, say). A measure of the range left out is removed, and measures [] removes the whole range. The other tracks follow column by column, as in the editor: a column is inserted, removed or given a time signature on every track; its repeat signs are carried as the editor carries them, and a tempo change stays on its column (on the next one when its column is removed), so no other column changes tempo. A note may be written by its pitch (E4, Bb3) in place of fret.string: Cesure chooses its string and fret, and never moves a note written with its string. The answer names the measures written. A written measure that does not read or does not fill its time signature refuses the whole call, the refusal naming each fault with its place; a measure sent back unchanged (same id and content) is kept as it was. Measure notation (.cesure): each voice is one string of beats separated by spaces. beat = content.duration[{d | tu 3}]; content = fret.string[{note props}] | pitch | (note note …) | r. Durations, on EVERY beat: 1 whole, 2 half, 4 quarter, 8, 16, 32, 64. Strings from 1 (the highest); x as fret mutes. A pitch (C4 = middle C, F#3, Bb2) lets Cesure choose string and fret; a staff is all by pitch or all fret.string. Beat props: d dotted, tu 3 triplet on each beat of the group. Note props: t tie, h hammer/pull-off and sl slide to the next note on that string, v vibrato, b (0 4) a whole-tone bend. EACH VOICE FILLS ITS TIME SIGNATURE EXACTLY: 4/4 = 4 quarters = 8 eighths, 3/4 = 3 quarters, 6/8 = 6 eighths; rests complete a short one. A measure without numerator/denominator is 4/4, whatever came before. A second voice (a bass under a melody)…
| Name | Type | Req | Description |
|---|---|---|---|
| draft | string | yes | The draft: the id a previous tool gave (draft). |
| from | integer | yes | First measure replaced, from 1. |
| measures | array | yes | The new measures, .cesure measure objects as read_score returns them; [] removes the range. |
| to | integer | yes | Last measure replaced; from - 1 to insert. |
| track | integer | – | The track, from 1 (default 1). |
Structured output declared, but exposes no named fields.
No examples provided.
import_score Import a score ~98
Open as a draft a score the person gives whole: a .cesure file's text, AlphaTex, or an "Open in Cesure" link. The score is taken as it is, never rewritten. A link to any other page (a video, a recording) opens nothing: Cesure reads no page.
| Name | Type | Req | Description |
|---|---|---|---|
| score | string | yes | The .cesure text, AlphaTex, or Open in Cesure link, verbatim. |
Structured output declared, but exposes no named fields.
No examples provided.
list_my_scores List my scores ~113
The scores of the person's linked Cesure account ("My scores"), the most recently changed at the top, 200 a call (offset skips that many; when there are more, the answer's more gives the next offset): id, title, when last changed, and its tags; then every tag of the account, with how many scores carry it. Needs the account linked.
| Name | Type | Req | Description |
|---|---|---|---|
| offset | integer | – | How many scores to skip, most recent first (default 0): the answer's more gives the next. |
Structured output declared, but exposes no named fields.
No examples provided.
open_in_cesure Open in Cesure ~84
Show the draft in the Cesure player, to read and hear it. Where the host draws apps, the player plays the draft in the conversation; everywhere, the answer gives the short link that opens it in Cesure, with no account, and the score's summary.
| Name | Type | Req | Description |
|---|---|---|---|
| draft | string | yes | The draft: the id a previous tool gave (draft). |
Structured output declared, but exposes no named fields.
No examples provided.
organize_my_scores Organize my scores ~188
Organize the scores of the linked account with tags, in ONE batch applied whole or not at all (at most 500 changes, counting the tags add creates): create_tags creates tags, add puts a tag on a score (creating the tag if the account has none of that name; names compare without case), remove takes it off, delete_unused_tags deletes tags no score carries. It never renames, deletes or changes a score, and no score's date moves. The opposite changes reverse an organizing (remove what add put, delete_unused_tags for the tags it created). Needs the account linked.
| Name | Type | Req | Description |
|---|---|---|---|
| add | array | – | Tags to put on scores. |
| create_tags | array | – | Tags to create, by name. |
| delete_unused_tags | array | – | Tags to delete if no score carries them, by name. |
| remove | array | – | Tags to take off scores. |
Structured output declared, but exposes no named fields.
No examples provided.
read_my_score Open one of my scores ~68
Open one score of the linked account as a draft, by the id list_my_scores gives: the answer is the draft and the score's summary; read_score reads its measures. Needs the account linked.
| Name | Type | Req | Description |
|---|---|---|---|
| id | string | yes | The score's id, as list_my_scores gives it. |
Structured output declared, but exposes no named fields.
No examples provided.
read_score Read measures ~169
Read measures from..to of a track of the draft (all by default, 200 at most a call: past them, the answer's more says where to go on) as .cesure measures — id, time signature, voices in the compact notation (second voice, hands, ties included) — with the repeat signs and tempo changes of those measures, by id, a summary of the score and one of the track.
| Name | Type | Req | Description |
|---|---|---|---|
| draft | string | yes | The draft: the id a previous tool gave (draft). |
| from | integer | – | First measure, from 1 (default 1). |
| to | integer | – | Last measure (default the last; at most 200 are read a call). |
| track | integer | – | The track, from 1 (default 1). |
Structured output declared, but exposes no named fields.
No examples provided.
refinger Place the notes again ~120
Place the notes of the draft again on the neck (string and fret), keeping their pitches: mode auto, standard (lowest frets) or optimized (fewest hand moves); searchCapo lets it choose a capo.
| Name | Type | Req | Description |
|---|---|---|---|
| draft | string | yes | The draft: the id a previous tool gave (draft). |
| mode | string | – | auto (default), standard or optimized. |
| searchCapo | boolean | – | Let the placement choose a capo (default false). |
| track | integer | – | The track, from 1 (default every track). |
Structured output declared, but exposes no named fields.
No examples provided.
save_new_score Save as a new score ~87
Save the draft as a NEW score in the linked account's library (never overwrites one; a free account keeps 3 scores), under a title (default the score's own). Needs the account linked.
| Name | Type | Req | Description |
|---|---|---|---|
| draft | string | yes | The draft: the id a previous tool gave (draft). |
| title | string | – | The title in the library (default the score's own). |
Structured output declared, but exposes no named fields.
No examples provided.
search_catalog Search the catalog ~93
Search Cesure's catalog of free pieces by words of a title, a composer or both: a piece is found when each word is in one of them, a short joining word such as 'by' aside; returns title, artist, licence and link.
| Name | Type | Req | Description |
|---|---|---|---|
| language | string | – | en (default), fr or es. |
| query | string | – | Words of a title or a composer; empty lists the catalog. |
Structured output declared, but exposes no named fields.
No examples provided.
transpose Transpose ~372
Shift the notes of the draft by some semitones; the placement follows, and no note keeps a wrong pitch. A note no string of its track carries at its shifted pitch goes where notesOffTheNeck says: retune_lowest_string tunes the lowest string of the track down to the lowest of those it carries (4 semitones at most), then moves the others by octaves; change_octave moves each by the octaves that put it on the neck. A harmonic that rings in its own form at no shifted string goes where harmonicsOffTheNeck says: keep_harmonic keeps it a harmonic at the octave that holds it, play_fretted plays it as a fretted note at its pitch, losing the harmonic's timbre. By default the lowest string when it carries the notes with no octave, else octaves, and harmonics kept when an octave holds them; play_fretted when no harmonic leaves the neck changes nothing. A choice that cannot place the notes is refused, saying why and naming the one that can. The answer names each string tuned down (retunedStrings: track, string, from, to) and counts the notes moved by octaves (notesMovedByOctaves) and the harmonics played fretted (harmonicsPlayedFretted).
| Name | Type | Req | Description |
|---|---|---|---|
| draft | string | yes | The draft: the id a previous tool gave (draft). |
| harmonicsOffTheNeck | string | – | keep_harmonic or play_fretted (default the first when an octave holds the harmonic). |
| notesOffTheNeck | string | – | retune_lowest_string or change_octave (default the first when it carries the notes with no octave). |
| semitones | integer | yes | Semitones, -24 to 24. |
Structured output declared, but exposes no named fields.
No examples provided.
undo_last_change Undo the last change ~94
Give the draft back the score it held before its last change (edit_measures, transpose, refinger, or an undo): the score it holds now becomes the one before, so calling it again redoes. One step only, and only when Cesure had room to keep that score; it says so when it had not.
| Name | Type | Req | Description |
|---|---|---|---|
| draft | string | yes | The draft: the id a previous tool gave (draft). |
Structured output declared, but exposes no named fields.
No examples provided.
update_my_score Save over my score ~85
Write the draft back over the score of the linked account's library it was opened from (read_my_score), as saving in the app does: refused, nothing overwritten, when the score was saved in Cesure since. The library keeps the score's earlier version. Needs the account linked.
| Name | Type | Req | Description |
|---|---|---|---|
| draft | string | yes | The draft: the id a previous tool gave (draft). |
Structured output declared, but exposes no named fields.
No examples provided.
How do I install the Cesure MCP server?
Cesure is a hosted endpoint at https://api.cesure.app/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.
remote · api.cesure.app
claude mcp add --transport http app-cesure-cesure 'https://api.cesure.app/mcp'
What is the Cesure MCP server?
Cesure is an MCP server listed in the public MCP registry as app.cesure/cesure. Write, edit, transpose and play guitar tabs and staff notation in Cesure. This page covers its hosted endpoint (https://api.cesure.app/mcp).
Is the Cesure MCP server safe to use?
Cesure scores 66 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.
What tools does the Cesure MCP server expose?
Cesure exposes 14 tools: create_score, import_score, read_score, edit_measures, transpose, and 9 more. Their descriptions and schemas cost roughly 3,344 tokens of context every time the server is loaded.
Does the Cesure MCP server require authentication?
No. We connected to Cesure without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the Cesure MCP server still maintained?
Cesure is still listed as active in the MCP registry. We last reached this channel on 24 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.