D Fetcher
REMOTE · DFETCHER.COM · SCANNED SEP 24
Vitamin D synthesis calculator: sun position, UV, IU/min, time to dose, sunburn risk, daily window.
Available components
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 Security57
- 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 3 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
- HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
- 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 Usability74
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 488 tokens (~162/item across 3 items; 3 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 Management100
- No destabilizing schema changes in the last 30 days.Pass
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 3 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 4 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
How do I install the D Fetcher MCP server?
D Fetcher is a hosted endpoint at https://dfetcher.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 · dfetcher.com
claude mcp add --transport http com-dfetcher-vitamin-d 'https://dfetcher.com/mcp'
{
"mcpServers": {
"com-dfetcher-vitamin-d": {
"url": "https://dfetcher.com/mcp"
}
}
} {
"servers": {
"com-dfetcher-vitamin-d": {
"type": "http",
"url": "https://dfetcher.com/mcp"
}
}
} [mcp_servers.com-dfetcher-vitamin-d] url = "https://dfetcher.com/mcp"
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"com-dfetcher-vitamin-d": {
"type": "remote",
"url": "https://dfetcher.com/mcp",
"enabled": true
}
}
} openclaw mcp add com-dfetcher-vitamin-d --url 'https://dfetcher.com/mcp' --transport streamable-http
mcp_servers:
com-dfetcher-vitamin-d:
url: "https://dfetcher.com/mcp" {
"McpServers": {
"com-dfetcher-vitamin-d": {
"Transport": "http",
"Url": "https://dfetcher.com/mcp"
}
}
} assistant mcp add com-dfetcher-vitamin-d -t streamable-http -u 'https://dfetcher.com/mcp'
{
"mcpServers": {
"com-dfetcher-vitamin-d": {
"type": "http",
"url": "https://dfetcher.com/mcp"
}
}
} The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.
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.
- 26 Aug 26 77
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 25 Aug 26 0
- Stability: 0.97 → pass security
- 11 Aug 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 31 Jul 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 30 Jul 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 27 Jul 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 26 Jul 26 0
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 Sept 2026 · Probed https://dfetcher.com/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=dfetcher.com | CN=WE1,O=Google Trust Services,C=US | 23 Sept 2026 | 22 Dec 2026 | ECDSA 256 | ECDSA-SHA256 | b10a32e477a780f3130cefb07c59e0ca |
| SANs: dfetcher.com | ||||||
| CN=WE1,O=Google Trust Services,C=US (CA) | CN=GTS Root R4,O=Google Trust Services LLC,C=US | 13 Dec 2023 | 20 Feb 2029 | ECDSA 256 | ECDSA-SHA384 | 7ff31977972c224a76155d13b6d685e3 |
| CN=GTS Root R4,O=Google Trust Services LLC,C=US (CA) | CN=GlobalSign Root CA,OU=Root CA,O=GlobalSign nv-sa,C=BE | 15 Nov 2023 | 28 Jan 2028 | ECDSA 384 | SHA256-RSA | 7fe530bf331343bedd821610493d8a1b |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of dfetcher.com. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| com. | present | 19718 | 13 | Verified |
| dfetcher.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 |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://dfetcher.com/mcp | Verified | 200 | |
| http (plaintext) | http://dfetcher.com/mcp | HTTPS enforced | 301 | https://dfetcher.com/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 →
calculate Vitamin D synthesis calculator ~265
Calculate vitamin D synthesis at a given location and time. Returns sun position, UV index, IU/min, minutes to reach the target dose, MED (sunburn threshold), the peak window, and optional 15-min day / monthly year curves. UV index uses a live satellite-driven forecast where available, with a clear-sky fallback.
| Name | Type | Req | Description |
|---|---|---|---|
| age | integer | – | Age in years (used for the age factor). |
| area | number | – | Exposed body fraction. 0.10 face+hands, 0.25 arms+face, 0.40 t-shirt+shorts, 0.85 near-full body. |
| date | string | – | ISO 8601 timestamp or epoch ms. Defaults to now. |
| day | boolean | – | Include 15-min samples through the local day. |
| lat | number | yes | Latitude in degrees. |
| lon | number | yes | Longitude in degrees. |
| scalp | string | – | Scalp coverage. "bald" adds ~3.5% BSA. |
| skin | integer | – | Fitzpatrick skin type 1–6. Use describe_skin_types if unknown. |
| target | integer | – | Daily vitamin D target in IU. |
| year | boolean | – | Include monthly solar-noon samples with cloud climatology. |
No output schema declared.
No examples provided.
describe_skin_types Fitzpatrick skin type reference ~46
Returns the six Fitzpatrick skin types with sun-reactivity behavior and descriptive ancestry hints. Call this when the user's skin type is unknown so you can pick the closest match before calling calculate.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
geocode Resolve a place to lat/lon ~116
Turn a place name, postal code, or "code, CC" string into { lat, lon, label }. Auto-detects US/CA/GB/NL/JP/BR postal patterns; ambiguous digit-only codes default to US unless the caller appends a country code (e.g. "10115, DE"). Falls back to Open-Meteo place-name search for everything else.
| Name | Type | Req | Description |
|---|---|---|---|
| query | string | yes | City name, postal code, or "CODE, CC" (e.g. "75001, FR"). |
No output schema declared.
No examples provided.
What is the D Fetcher MCP server?
D Fetcher is an MCP server listed in the public MCP registry as com.dfetcher/vitamin-d. Vitamin D synthesis calculator: sun position, UV, IU/min, time to dose, sunburn risk, daily window. This page covers its hosted endpoint (https://dfetcher.com/mcp).
Is the D Fetcher MCP server safe to use?
D Fetcher scores 77 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 D Fetcher MCP server expose?
D Fetcher exposes 3 tools: calculate, geocode, describe_skin_types. Their descriptions and schemas cost roughly 427 tokens of context every time the server is loaded.
Does the D Fetcher MCP server require authentication?
No. We connected to D Fetcher without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the D Fetcher MCP server still maintained?
D Fetcher is still listed as active in the MCP registry. We last reached this channel on 24 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.