SingleFax
REMOTE · SINGLEFAX.COM · SCANNED SEP 21
Send a fax from Claude, ChatGPT, or Cursor. Upload a PDF, pay, get delivery status.
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 Security97
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- The endpoint enforces authorisation, advertised via RFC 9728 protected-resource metadata. View diagnostics → Pass
- 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
- The authorisation server offers only Dynamic Client Registration (RFC 7591), which MCP 2026-07-28 deprecated in favour of Client ID Metadata Documents. View diagnostics → Partial
Transport & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability59
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 373 tokens (~373/item across 0 items; 0 tools + 0 resources), over budget; trim descriptions and params. See how to fix → Fail
- Nothing to assess: this server has no tools to check for usage examples. See how to fix → Fail
Stability & Change Management0
- Stability check failed: schema churn in the 18 days we've observed: 8 tool removals, 0 breaking changes, 0 auth/transport breaks, 0 additions. See how to fix → Fail
Tool Coverage0
- Tool coverage not yet verified: we couldn't read the endpoint's tools.Unverified
Tool Safety0
- Tool safety not yet verified: we couldn't read the endpoint's tools.Unverified
Capabilities100
- Implements a current MCP spec version (2026-07-28).Pass
Unverified: 2 categories
Categories scored 0 because we could not verify them: authentication we do not have, an unreachable endpoint, or not enough scan history. We only credit what we can confirm.
How do I install the SingleFax MCP server?
SingleFax is a hosted endpoint at https://singlefax.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 · singlefax.com
claude mcp add --transport http com-singlefax-mcp 'https://singlefax.com/mcp'
{
"mcpServers": {
"com-singlefax-mcp": {
"url": "https://singlefax.com/mcp"
}
}
} {
"servers": {
"com-singlefax-mcp": {
"type": "http",
"url": "https://singlefax.com/mcp"
}
}
} [mcp_servers.com-singlefax-mcp] url = "https://singlefax.com/mcp"
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"com-singlefax-mcp": {
"type": "remote",
"url": "https://singlefax.com/mcp",
"enabled": true
}
}
} openclaw mcp add com-singlefax-mcp --url 'https://singlefax.com/mcp' --transport streamable-http
mcp_servers:
com-singlefax-mcp:
url: "https://singlefax.com/mcp" {
"McpServers": {
"com-singlefax-mcp": {
"Transport": "http",
"Url": "https://singlefax.com/mcp"
}
}
} assistant mcp add com-singlefax-mcp -t streamable-http -u 'https://singlefax.com/mcp'
{
"mcpServers": {
"com-singlefax-mcp": {
"type": "http",
"url": "https://singlefax.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.
- 21 Sept 26 −1
- This server's schema is too large to store in full, so we cannot compare its tools day to day functional
- 20 Sept 26 0
- This server's schema is too large to store in full, so we cannot compare its tools day to day functional
- 19 Sept 26 0
- This server's schema is too large to store in full, so we cannot compare its tools day to day functional
- 18 Sept 26 0
- This server's schema is too large to store in full, so we cannot compare its tools day to day functional
- 17 Sept 26 0
- This server's schema is too large to store in full, so we cannot compare its tools day to day functional
- 16 Sept 26 0
- This server's schema is too large to store in full, so we cannot compare its tools day to day functional
- 15 Sept 26 0
- This server's schema is too large to store in full, so we cannot compare its tools day to day functional
- 14 Sept 26 0
- This server's schema is too large to store in full, so we cannot compare its tools day to day functional
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 21 Sept 2026 · Probed https://singlefax.com/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=singlefax.com | CN=WE1,O=Google Trust Services,C=US | 7 Aug 2026 | 5 Nov 2026 | ECDSA 256 | ECDSA-SHA256 | b3a09bde8a13e48b0ef758844688eaa9 |
| SANs: singlefax.com, mta-sts.singlefax.com, *.mta-sts.singlefax.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 secure
Validation of singlefax.com. — Secure
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| com. | present | 19718 | 13 | Verified |
| singlefax.com. | present | 2371 | 13 | Verified |
| singlefax.com. | Verified address RRset verified with the apex keys |
Authentication Enforced and verified
The endpoint asked for a token and published valid RFC 9728 metadata describing how to get one.
| Result | Enforced and verified |
|---|---|
| Enforced | On connection |
| HTTP status | 401 |
WWW-Authenticate challenge Bearer realm="mcp", resource="https://singlefax.com/mcp", resource_metadata="https://singlefax.com/.well-known/oauth-protected-resource/mcp", error="invalid_token", error_description="Unauthorized"
Bearer realm="mcp", resource="https://singlefax.com/mcp", resource_metadata="https://singlefax.com/.well-known/oauth-protected-resource/mcp", error="invalid_token", error_description="Unauthorized"| Header | Value |
|---|---|
| strict-transport-security | max-age=31536000; includeSubDomains; preload |
| x-content-type-options | nosniff |
| x-frame-options | SAMEORIGIN |
| referrer-policy | same-origin |
| permissions-policy | accelerometer=(), camera=(), geolocation=(), gyroscope=(), magnetometer=(), microphone=(), payment=(), usb=() |
| www-authenticate | Bearer realm="mcp", resource="https://singlefax.com/mcp", resource_metadata="https://singlefax.com/.well-known/oauth-protected-resource/mcp", error="invalid_token", error_description="Unauthorized" |
Protected resource metadata
| Document | https://singlefax.com/.well-known/oauth-protected-resource/mcp |
|---|---|
| Retrieved | Yes |
| Resource | https://singlefax.com/mcp |
| Authorisation server | https://api.singlefax.com/api/auth |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://singlefax.com/mcp | Verified | 200 | |
| http (plaintext) | http://singlefax.com/mcp | HTTPS enforced | 301 | https://singlefax.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 →
No tool schema has been captured from this endpoint yet.
What is the SingleFax MCP server?
SingleFax is an MCP server listed in the public MCP registry as com.singlefax/mcp. Send a fax from Claude, ChatGPT, or Cursor. Upload a PDF, pay, get delivery status. This page covers its hosted endpoint (https://singlefax.com/mcp).
Is the SingleFax MCP server safe to use?
SingleFax scores 63 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.
Does the SingleFax MCP server require authentication?
Yes. SingleFax asked us for credentials when we connected, so you will need to authorise it in your MCP client before it can do anything.
Is the SingleFax MCP server still maintained?
SingleFax is still listed as active in the MCP registry. We last reached this channel on 21 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.