DiffiCat
REMOTE · APP.DIFFICAT.COM · SCANNED SEP 28
Compare a website before and after a migration: missing pages, content changes, visual diffs.
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 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 9 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 Usability67
- AI-judged instruction clarity (good).Pass
- Context-footprint check failed: tool/resource definitions use about 1351 tokens (~150/item across 9 items; 9 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 Management10
- Stability observed for 3 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage95
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 86% 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 9 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
Capabilities100
- Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
How do I install the DiffiCat MCP server?
DiffiCat is a hosted endpoint at https://app.difficat.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 · app.difficat.com
claude mcp add --transport http com-difficat-difficat 'https://app.difficat.com/mcp'
{
"mcpServers": {
"com-difficat-difficat": {
"url": "https://app.difficat.com/mcp"
}
}
} {
"servers": {
"com-difficat-difficat": {
"type": "http",
"url": "https://app.difficat.com/mcp"
}
}
} [mcp_servers.com-difficat-difficat] url = "https://app.difficat.com/mcp"
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"com-difficat-difficat": {
"type": "remote",
"url": "https://app.difficat.com/mcp",
"enabled": true
}
}
} openclaw mcp add com-difficat-difficat --url 'https://app.difficat.com/mcp' --transport streamable-http
mcp_servers:
com-difficat-difficat:
url: "https://app.difficat.com/mcp" {
"McpServers": {
"com-difficat-difficat": {
"Transport": "http",
"Url": "https://app.difficat.com/mcp"
}
}
} assistant mcp add com-difficat-difficat -t streamable-http -u 'https://app.difficat.com/mcp'
{
"mcpServers": {
"com-difficat-difficat": {
"type": "http",
"url": "https://app.difficat.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.
- 28 Sept 26 −1
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 27 Sept 26 0
- Tool “cancel_comparison” rewrote its description, which is the text the model reads security
- Tool “get_report” rewrote its description, which is the text the model reads security
- Tool “start_comparison” rewrote its description, which is the text the model reads security
- Schema quality: 91 → 114 ▼ functional
- Server version: 3.22.6 → 3.25.5 functional
- “get_report” added an optional parameter “limit” cosmetic
- “get_report” added an optional parameter “offset” cosmetic
- “start_comparison” reworded the description of “maxPages” cosmetic
- “start_comparison” reworded the description of “urls” cosmetic
- “start_comparison” made “maxPages” optional cosmetic
- 26 Sept 26 +1
- Stability: unverified → 0.03 ▲ functional
- Server version: 3.22.4 → 3.22.6 functional
- 25 Sept 26 67
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 28 Sept 2026 · Probed https://app.difficat.com/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=app.difficat.com | CN=WR3,O=Google Trust Services,C=US | 30 Aug 2026 | 28 Nov 2026 | RSA 2048 | SHA256-RSA | ac5a7b3913a517c212785fce19276835 |
| SANs: app.difficat.com | ||||||
| CN=WR3,O=Google Trust Services,C=US (CA) | CN=GTS Root R1,O=Google Trust Services LLC,C=US | 13 Dec 2023 | 20 Feb 2029 | RSA 2048 | SHA256-RSA | 7ff005a91568d63abc22861684aa4b5a |
| CN=GTS Root R1,O=Google Trust Services LLC,C=US (CA) | CN=GlobalSign Root CA,OU=Root CA,O=GlobalSign nv-sa,C=BE | 19 Jun 2020 | 28 Jan 2028 | RSA 4096 | SHA256-RSA | 77bd0d6cdb36f91aea210fc4f058d30d |
Background: What to check on a remote MCP endpoint →
DNSSEC secure
Validation of app.difficat.com. — Secure
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| com. | present | 19718 | 13 | Verified |
| difficat.com. | present | 33021 | 13 | Verified |
| app.difficat.com. | 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=31536000; includeSubDomains |
| content-security-policy | default-src 'self';script-src 'self' https://accounts.google.com https://www.googletagmanager.com;style-src 'self' 'unsafe-inline' https://fonts.googleapis.com https://accounts.google.com;img-src 'self' data: blob: https://*.googleusercontent.com https://*.google-analytics.com https://*.googletagmanager.com;connect-src 'self' https://accounts.google.com https://*.google-analytics.com https://*.analytics.google.com https://*.googletagmanager.com;font-src 'self' https://fonts.gstatic.com;frame-src https://accounts.google.com;object-src 'none';frame-ancestors 'none';base-uri 'self';form-action 'self';script-src-attr 'none';upgrade-insecure-requests |
| x-content-type-options | nosniff |
| x-frame-options | SAMEORIGIN |
| referrer-policy | no-referrer |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://app.difficat.com/mcp | Verified | 200 | |
| http (plaintext) | http://app.difficat.com/mcp | HTTPS enforced | 302 | https://app.difficat.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 →
cancel_comparison Cancel comparison ~81
Stop a running job; the job reports cancelled within a minute, with the pages compared so far in its report. Free.
| Name | Type | Req | Description |
|---|---|---|---|
| jobId | string | yes | – |
| jobToken | string | – | The jobToken returned when the job was created. Optional when the request carries the prepaid key that paid the job (Authorization: Bearer dck_…). |
No output schema declared.
No examples provided.
capture_screenshot Capture screenshot ~124
Full-page PNG of one URL. Returns the image (or, for a large one, links.file to fetch with the jobToken) plus a jobId/jobToken for get_screenshot. Paid in USDC (the 402 challenge names the network), or from a prepaid balance when the request carries Authorization: Bearer dck_…: 0.02 USD per call.
| Name | Type | Req | Description |
|---|---|---|---|
| auth | object | – | HTTP basic auth for the page. |
| url | string | yes | Page to capture (full URL). |
| viewportWidth | integer | – | Capture width in px. |
No output schema declared.
No examples provided.
discover_pages Discover pages ~130
List the pages of Site A (sitemap, robots.txt, or crawl), mapped onto Site B when given. Paid in USDC (the 402 challenge names the network), or from a prepaid balance when the request carries Authorization: Bearer dck_…: 0.05 USD per call.
| Name | Type | Req | Description |
|---|---|---|---|
| maxPages | integer | – | Stop after this many pages. |
| sitemapUrl | string | – | Sitemap to read instead of the fallbacks. |
| sourceUrl | string | yes | Site A (full URL). |
| targetUrl | string | – | Site B; pages are mapped onto it when given. |
No output schema declared.
No examples provided.
get_balance Get prepaid balance ~35
The prepaid balance and the last 20 ledger entries of the key the request carries as Authorization: Bearer dck_…. Free.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
get_comparison Get comparison status ~65
Status and progress of a job. Free.
| Name | Type | Req | Description |
|---|---|---|---|
| jobId | string | yes | – |
| jobToken | string | – | The jobToken returned when the job was created. Optional when the request carries the prepaid key that paid the job (Authorization: Bearer dck_…). |
No output schema declared.
No examples provided.
get_report Get report ~159
The finished report: summary over every page, a slice of the per-page results (offset and limit, default 50 a call, at most 5000; nextOffset points at the next slice), and the plain-text report over that slice. limit: 1 returns the summary with one result. Free.
| Name | Type | Req | Description |
|---|---|---|---|
| jobId | string | yes | – |
| jobToken | string | – | The jobToken returned when the job was created. Optional when the request carries the prepaid key that paid the job (Authorization: Bearer dck_…). |
| limit | integer | – | Page results to return (default 1000, at most 5000). |
| offset | integer | – | Index of the first page result to return (default 0). |
No output schema declared.
No examples provided.
get_screenshot Get screenshot ~100
A screenshot PNG named in the report or returned by capture_screenshot; a large one comes back as links.file to fetch with the jobToken. Free.
| Name | Type | Req | Description |
|---|---|---|---|
| filename | string | yes | A screenshot filename from the report. |
| jobId | string | yes | – |
| jobToken | string | – | The jobToken returned when the job was created. Optional when the request carries the prepaid key that paid the job (Authorization: Bearer dck_…). |
No output schema declared.
No examples provided.
recover_comparison Recover a paid job ~45
Returns the job or screenshot the payment credential in _meta paid for, with a new jobToken that replaces the old one. For a paid call whose result never arrived. Free.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
start_comparison Start comparison ~612
Compare Site A against Site B on page existence, content and visual regression. Charged upfront. Paid in USDC (the 402 challenge names the network), or from a prepaid balance when the request carries Authorization: Bearer dck_…: 0.02 USD per page for the first 1000 pages and 0.01 USD per page beyond. maxPages is optional: a ceiling, not a reservation. A job is priced on the pages it compares (the urls list, or the pages discovery finds, at most maxPages), the challenge names the count, and there is no page limit. A single-page comparison is a urls list with one pair (preferred), or maxPages: 1 with the page URLs as sourceUrl and targetUrl; either is priced as one page and runs no discovery. One single-page comparison per client address per day is free when the request carries no payment credential and no prepaid key: the response is the normal 201 with sample: true and pagesCharged: 0, and once the allowance is used the same request is challenged as usual. A sample report over three pages, produced by this API, is at https://difficat.com/agents/sample/report.json. The discovery that prices a job without urls is not charged; discover_pages is a separate, optional purchase for callers who want the page list itself. Set maxPriceUsd to refuse a job priced above your budget before any challenge. A settled charge is final: cancelling, a failed job or partial results do not reduce it. recover_comparison returns a job whose result was lost, given the same payment credential. Poll get_comparison, then get_report (paged with offset and limit).
| Name | Type | Req | Description |
|---|---|---|---|
| maxPages | integer | – | Optional ceiling on the pages compared and charged for. The job is priced on the pages it compares: the urls list, or the pages discovery finds, at most this many. There is no page limit. |
| maxPriceUsd | number | – | Optional spend cap in USD. A job priced above it is refused before any challenge, so an auto-paying client is never asked for more. |
| sitemapUrl | string | – | Sitemap to discover pages from. |
| sourceAuth | object | – | HTTP basic auth for Site A. |
| sourceUrl | string | – | Site A, the reference site (full URL). Required unless urls is given. |
| targetAuth | object | – | HTTP basic auth for Site B. |
| targetUrl | string | – | Site B, the migrated site. Omit to capture screenshots of Site A only. |
| threshold | number | – | Visual diff tolerance as a fraction from 0 (exact) to 1: 0.05 means 5%. The web app takes a percentage; the API does not. |
| urls | array | – | Explicit page pairs to compare; skips discovery and is priced per pair. One pair is a single-page comparison and needs no sourceUrl. |
| viewportWidth | integer | – | Capture width in px. |
No output schema declared.
No examples provided.
What is the DiffiCat MCP server?
DiffiCat is an MCP server listed in the public MCP registry as com.difficat/difficat. Compare a website before and after a migration: missing pages, content changes, visual diffs. This page covers its hosted endpoint (https://app.difficat.com/mcp).
Is the DiffiCat MCP server safe to use?
DiffiCat scores 67 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 DiffiCat MCP server expose?
DiffiCat exposes 9 tools: discover_pages, capture_screenshot, start_comparison, recover_comparison, get_comparison, and 4 more. Their descriptions and schemas cost roughly 1,351 tokens of context every time the server is loaded.
Does the DiffiCat MCP server require authentication?
No. We connected to DiffiCat without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the DiffiCat MCP server still maintained?
DiffiCat is still listed as active in the MCP registry. We last reached this channel on 28 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.