Lettras word search
REMOTE · MCP.LETTRAS.ORG
Word searches, crosswords, sudoku and Unicode text styles in 6 languages, accents kept.
Available components
Last scanned (1 hour ago)
Scores higher than 66% of remote servers
Reachable. Last reached 5 Nov 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 not fully verified: no authorisation is required to call this server, and 8 tool(s) never declared a destructiveHint. The MCP spec treats an absent hint as destructive by default, so we cannot call this surface safe. See how to fix → View diagnostics → Unverified
- 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 Usability64
- AI-judged instruction clarity (good).Pass
- Context-footprint check failed: tool/resource definitions use about 1417 tokens (~177/item across 8 items; 8 tools + 0 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 Management83
- Stability observed for 25 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
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 8 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 9 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities60
- Spec-recency check failed: implements MCP spec 2025-06-18; the latest is 2026-07-28. See how to fix → Fail
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.
- 4 Nov 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 77 to 80. That category is still filling its 30-day observation window: 23 days of observed history at the previous scan, 24 at this one. The score rises as the window fills, whether or not the server changes.
- 2 Nov 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 70 to 73. That category is still filling its 30-day observation window: 21 days of observed history at the previous scan, 22 at this one. The score rises as the window fills, whether or not the server changes.
- 31 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 63 to 67. That category is still filling its 30-day observation window: 19 days of observed history at the previous scan, 20 at this one. The score rises as the window fills, whether or not the server changes.
- 29 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 57 to 60. That category is still filling its 30-day observation window: 17 days of observed history at the previous scan, 18 at this one. The score rises as the window fills, whether or not the server changes.
- 27 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 50 to 53. That category is still filling its 30-day observation window: 15 days of observed history at the previous scan, 16 at this one. The score rises as the window fills, whether or not the server changes.
- 25 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 43 to 47. That category is still filling its 30-day observation window: 13 days of observed history at the previous scan, 14 at this one. The score rises as the window fills, whether or not the server changes.
- 22 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 33 to 37. That category is still filling its 30-day observation window: 10 days of observed history at the previous scan, 11 at this one. The score rises as the window fills, whether or not the server changes.
- 20 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 27 to 30. That category is still filling its 30-day observation window: 8 days of observed history at the previous scan, 9 at this one. The score rises as the window fills, whether or not the server changes.
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 5 Nov 2026 · Probed https://mcp.lettras.org/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=mcp.lettras.org | CN=YR1,O=Let's Encrypt,C=US | 8 Oct 2026 | 6 Jan 2027 | RSA 2048 | SHA256-RSA | 6fd0e88d819125ea60d4c07c3d37b93fa97 |
| SANs: mcp.lettras.org | ||||||
| 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 mcp.lettras.org. — Secure
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| org. | present | 725, 26974 | 8, 8 | Verified |
| lettras.org. | present | 54179 | 13 | Verified |
| mcp.lettras.org. | 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 |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://mcp.lettras.org/mcp | Verified | 200 | |
| http (plaintext) | http://mcp.lettras.org/mcp | HTTPS enforced | 308 | https://mcp.lettras.org/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 →
crossword Generate a crossword (crucigrama) ~303
Lays out a crossword from words with clues. Returns two matrices of the same size: puzzle (the game position: "-" is a blank cell, a word's number is on its first cell, "0" marks the other cells where a letter goes, and "a/d" such as "3/4" appears when an across word and a down word start in the same cell) and solution (the same matrix with the correct letters, one grapheme per cell). placements lists every word with its number, clue, direction (across/down) and start cell; unplaced lists words that did not fit. Offer more words than you need: the engine keeps the best layout it finds. Native letters (Ñ, Ç, ẞ…) stay one cell each. Free, no usage limit. The same seed gives the same crossword.
| Name | Type | Req | Description |
|---|---|---|---|
| attempts | integer | – | Layouts to try (default 30); more attempts, denser crossword. |
| block | string | – | Marker of blank cells. Default "-". |
| classicMode | boolean | – | Strip accents (ñ becomes N). |
| cols | integer | – | Largest width. Default: rows. |
| entries | array | yes | Words with their clues. |
| open | string | – | Marker of letter cells that do not start a word in puzzle. Default "0". |
| rows | integer | yes | Largest height; the result is cropped to what it uses. |
| seed | integer | – | Repeatable crossword. |
No output schema declared.
No examples provided.
fill_word_search Fill a word search with random letters ~201
Completes a word search: takes the grid from generate_word_search (empty cells are "-") and fills them with random letters in the chosen language, with accents on or off. Letters follow how common they are in that language. Pass the puzzle's words so the filler never creates an extra copy of one.
| Name | Type | Req | Description |
|---|---|---|---|
| accents | boolean | – | true (default): use the language's accented/native letters (Ñ, Ç, Ã, Ä, ẞ…). false: plain A-Z only. |
| empty | string | – | What marks an empty cell. Default "-". |
| grid | array | yes | The grid from generate_word_search: rows of one-letter strings, "-" for empty cells. |
| lang | string | – | Language of the letters. Default es. |
| seed | integer | – | Repeatable filler. Omit for a different filler every time. |
| words | array | – | The hidden words, so the filler cannot create an extra copy of one. |
No output schema declared.
No examples provided.
generate_word_search Generate a word search ~305
Create a word-search puzzle (sopa de letras) from a list of words. Puzzles up to 10x10 with at most 10 words are free and unlimited; bigger ones use the free puzzles each client gets. Keeps native letters (Ñ, Ç, Ã, Ä, ẞ, È…) as one cell each. Returns the grid, where every word is hidden, and any words that did not fit. Empty cells are marked "-": call fill_word_search with the grid to complete it with random letters. The same seed always gives the same puzzle.
| Name | Type | Req | Description |
|---|---|---|---|
| classicMode | boolean | – | Strip accents in the grid (ñ becomes N). |
| clustering | number | – | 0 keeps words apart, 1 makes them cross. Default 0.5. |
| cols | integer | yes | Grid width. May differ from rows for a rectangular grid. |
| difficulty | integer | – | Used when position is not set: 1 easy (right, down) to 4 expert (all 8 directions). |
| lang | string | – | Language of the words. Default es. |
| position | string | – | horizontal = left to right only, vertical = top to bottom only, mixed = all 8 directions including diagonals. |
| rows | integer | yes | Grid height. |
| seed | integer | – | Repeatable puzzles: same input and seed, same grid. |
| words | array | yes | Words to hide, in their normal spelling (accents kept). |
No output schema declared.
No examples provided.
list_languages List supported languages ~25
Languages Lettras supports, with the native letters each one adds to its grid alphabet.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
list_styles List text styles ~48
The Unicode text styles stylize_text offers, with the id to pass, an English name and a category (bold-italic, sans, script, gothic, mono, enclosed, decoration, other).
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
solve_sudoku Solve a sudoku ~68
Solves a sudoku grid (0 = empty cell; sizes 4, 6, 9, 12, 16) and says whether the solution is the only one. Free, no usage limit.
| Name | Type | Req | Description |
|---|---|---|---|
| puzzle | array | yes | Rows of numbers, 0 for empty cells. |
No output schema declared.
No examples provided.
stylize_text Write text in Unicode styles ~257
Turns text into Unicode styles for social media bios and posts: bold, italic, script, fraktur, monospace, circled, squared, fullwidth, small caps, strikethrough, underline and more (22 styles). Accents are kept: an accented letter becomes its styled base letter plus the combining accent (ñ, ç, ü, ß work). Not every style can draw every character: letters such as ß, Æ, Œ, Ø or non-Latin scripts stay plain, and accented letters rely on a combining mark that some fonts draw badly. Those characters are listed in notNative for each style, and parts with missing: true mark them, so you can warn the user or show an empty box. Set classic to strip accents first. Pass one style id, several, or none for all styles (see list_styles). Runs locally and has no usage limit.
| Name | Type | Req | Description |
|---|---|---|---|
| classic | boolean | – | Strip accents first (ñ becomes n), for places that render combining accents badly. |
| style | – | – | Which style(s) to use. Omit for all 22. Ids come from list_styles. |
| text | string | yes | The text to style, in its normal spelling (accents kept). |
No output schema declared.
No examples provided.
sudoku Generate a sudoku ~114
Creates a sudoku with exactly one solution. Returns puzzle (0 = empty cell) and solution. Sizes 4, 6, 9 (default), 12 and 16; difficulty 1 easy (most clues) to 4 expert. Free, no usage limit. The same seed gives the same sudoku.
| Name | Type | Req | Description |
|---|---|---|---|
| difficulty | integer | – | 1 easy to 4 expert. Default 2. |
| seed | integer | – | Repeatable sudoku. |
| size | integer | – | Side of the grid. Default 9. |
No output schema declared.
No examples provided.
How do I install the Lettras word search MCP server?
Lettras word search is a hosted endpoint at https://mcp.lettras.org/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 · mcp.lettras.org
claude mcp add --transport http org-lettras-word-search 'https://mcp.lettras.org/mcp'
What is the Lettras word search MCP server?
Lettras word search is an MCP server listed in the public MCP registry as org.lettras/word-search. Word searches, crosswords, sudoku and Unicode text styles in 6 languages, accents kept. This page covers its hosted endpoint (https://mcp.lettras.org/mcp).
Is the Lettras word search MCP server safe to use?
Lettras word search scores 76 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 Lettras word search MCP server expose?
Lettras word search exposes 8 tools: generate_word_search, fill_word_search, stylize_text, list_styles, crossword, and 3 more. Their descriptions and schemas cost roughly 1,321 tokens of context every time the server is loaded.
Does the Lettras word search MCP server require authentication?
No. We connected to Lettras word search without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the Lettras word search MCP server still maintained?
Lettras word search is still listed as active in the MCP registry. We last reached this channel on 5 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.