uml.singsk.com PlantUML
REMOTE · UML.SINGSK.COM
Render, validate, encode/decode PlantUML diagram-as-code; 22 diagram types. Free, no auth.
Available components
Last scanned (7 hours ago)
Scores higher than 76% of remote servers
Reachable. Last reached 5 Nov 2026.
Category Design and Media
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 Security63
- 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 6 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 check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
Transport & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability79
- AI-judged instruction clarity (excellent).Pass
- Tool/resource definitions use about 669 tokens (~111/item across 6 items; 6 tools + 0 resources), lean.Pass
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management100
- No destabilizing schema changes in the last 30 days.Pass
Tool Coverage83
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 50% of tool parameters carry a description.Partial
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 6 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 7 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.
- 5 Nov 26 0
- Stability: 0.97 → pass security
- 4 Nov 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 93 to 97. That category is still filling its 30-day observation window: 28 days of observed history at the previous scan, 29 at this one. The score rises as the window fills, whether or not the server changes.
- 2 Nov 26 +15
- Injection markers: unverified → pass ▲ security
- TLS certificate: unverified → pass ▲ security
- HSTS header: unverified → pass ▲ security
- Transport: fail → pass ▲ security
- Authorization: Authorisation not fully verified: no authorisation is required to call this server, and 6 tool(s) never declared a destructiveHint. The MCP spec treats an absent hint as destructive by default, so we cannot call this surface safe. security
- MCP protocol: unverified → fail ▼ functional
- Endpoint reachability: unreachable → reachable ▲ functional
- Tool coverage: unverified → 100 ▲ functional
- Stability: unverified → 0.90 ▲ functional
- 1 Nov 26 −16
The score moved with no change recorded against any check. We would rather say so than guess.
- 30 Oct 26 0
- Endpoint reachability: reachable → unreachable ▼ security
- Stability: pass → unverified ▼ security
- Tool safety: pass → unverified ▼ security
- TLS certificate: pass → unverified ▼ security
- HSTS header: pass → unverified ▼ security
- Transport: pass → fail ▼ security
- Authorization: Authorisation not yet verified: we couldn't confirm whether this endpoint requires it. security
- Capabilities: fail → unverified ▼ functional
- Tool coverage: 100 → unverified ▼ functional
- 29 Oct 26 0
- Injection markers: unverified → pass ▲ security
- Stability: unverified → pass ▲ security
- TLS certificate: unverified → pass ▲ security
- HSTS header: unverified → pass ▲ security
- Transport: fail → pass ▲ security
- Authorization: Authorisation not fully verified: no authorisation is required to call this server, and 6 tool(s) never declared a destructiveHint. The MCP spec treats an absent hint as destructive by default, so we cannot call this surface safe. security
- MCP protocol: unverified → fail ▼ functional
- Endpoint reachability: unreachable → reachable ▲ functional
- Tool coverage: unverified → 100 ▲ functional
- 28 Oct 26 0
- Endpoint reachability: reachable → unreachable ▼ security
- Tool safety: pass → unverified ▼ security
- TLS certificate: pass → unverified ▼ security
- Stability: 0.97 → unverified ▼ security
- HSTS header: pass → unverified ▼ security
- Transport: pass → fail ▼ security
- Authorization: Authorisation not yet verified: we couldn't confirm whether this endpoint requires it. security
- Capabilities: fail → unverified ▼ functional
- Tool coverage: 100 → unverified ▼ functional
- 27 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 93 to 97. That category is still filling its 30-day observation window: 28 days of observed history at the previous scan, 29 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://uml.singsk.com/mcp
TLS valid
Negotiated TLS 1.2 with TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=singsk.com | CN=YR1,O=Let's Encrypt,C=US | 21 Oct 2026 | 19 Jan 2027 | RSA 2048 | SHA256-RSA | 543e06ddf0e55c26230219814f0ecae25d4 |
| SANs: *.singsk.com, singsk.com | ||||||
| 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 insecure
Validation of uml.singsk.com. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| com. | present | 19718 | 13 | Verified |
| singsk.com. | absent | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
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=31536000 |
| x-content-type-options | nosniff |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://uml.singsk.com/mcp | Verified | 200 | |
| http (plaintext) | http://uml.singsk.com/mcp | HTTPS enforced |
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 →
decode_token ~96
Recover the PlantUML source from a token or from any PlantUML render URL (the token is extracted automatically). Tokens use PlantUML's own 64-character alphabet ("0-9 A-Z a-z - _") over raw DEFLATE. This is NOT base64 - never encode or decode tokens with a base64 codec; use encode_source / decode_token.
| Name | Type | Req | Description |
|---|---|---|---|
| encoded | string | yes | Token or full render URL |
No output schema declared.
No examples provided.
encode_source ~142
Encode PlantUML source into a URL token and ready-to-use share/render URLs (svg + png). The result carries url_ok: GET URLs only work while the token is at most 16000 characters; when url_ok is false do not share the URLs - render with render_diagram instead (it uses the POST API, no size limit up to 5 MB). Tokens use PlantUML's own 64-character alphabet ("0-9 A-Z a-z - _") over raw DEFLATE. This is NOT base64 - never encode or decode tokens with a base64 codec; use encode_source / decode_token.
| Name | Type | Req | Description |
|---|---|---|---|
| text | string | yes | – |
No output schema declared.
No examples provided.
get_syntax_reference ~72
Get the syntax reference entry for one diagram type: description, a render-verified example, and the help page URL. Use it to ground diagram generation.
| Name | Type | Req | Description |
|---|---|---|---|
| type | string | yes | Type id or label, e.g. "sequence", "class", "mindmap", "gantt", "json" |
No output schema declared.
No examples provided.
list_diagram_types ~42
List the 22 supported diagram/reference types with a one-line description and the local syntax reference URL for each. Use it to pick the right @start directive.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
render_diagram ~120
Render PlantUML source text to a diagram image. Returns a PNG image block (format "png") or the SVG markup as text (format "svg", default), plus the shareable render URL. The source is validated first: on a syntax error the result is an error object with line, column, hint and a help link so you can fix the diagram and retry.
| Name | Type | Req | Description |
|---|---|---|---|
| format | string | – | – |
| text | string | yes | PlantUML source including @startuml ... @enduml (or the matching @start/@end pair) |
No output schema declared.
No examples provided.
validate_diagram ~75
Check PlantUML source without rendering. Returns {ok:true, diagram_type} or {ok:false, error:{code, message, line, column, source_line, hint, diagram_type_detected, help}}. Cheap - call it in a generate -> validate -> fix loop before rendering.
| Name | Type | Req | Description |
|---|---|---|---|
| text | string | yes | – |
No output schema declared.
No examples provided.
How do I install the uml.singsk.com PlantUML MCP server?
uml.singsk.com PlantUML is a hosted endpoint at https://uml.singsk.com/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 · uml.singsk.com
claude mcp add --transport http com-singsk-uml-plantuml 'https://uml.singsk.com/mcp'
What is the uml.singsk.com PlantUML MCP server?
uml.singsk.com PlantUML is an MCP server listed in the public MCP registry as com.singsk/uml-plantuml. Render, validate, encode/decode PlantUML diagram-as-code; 22 diagram types. Free, no auth. This page covers its hosted endpoint (https://uml.singsk.com/mcp).
Is the uml.singsk.com PlantUML MCP server safe to use?
uml.singsk.com PlantUML scores 78 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 uml.singsk.com PlantUML MCP server expose?
uml.singsk.com PlantUML exposes 6 tools: render_diagram, validate_diagram, encode_source, decode_token, list_diagram_types, get_syntax_reference. Their descriptions and schemas cost roughly 547 tokens of context every time the server is loaded.
Does the uml.singsk.com PlantUML MCP server require authentication?
No. We connected to uml.singsk.com PlantUML without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the uml.singsk.com PlantUML MCP server still maintained?
uml.singsk.com PlantUML 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.