FaxOnline
REMOTE · FAXONLINE.APP
Prepare and track US PDF faxes with user-approved checkout. No account or subscription.
Available components
Last scanned (18 hours ago)
Scores higher than 87% of remote servers
Reachable. Last reached 4 Nov 2026.
Category Documents and Files
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 Security77
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- No authorisation is required to call this server. Every tool declares its destructiveHint and none is destructive, so open access doesn't expose one. See how to fix → View diagnostics → Partial
- 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 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 Usability69
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 422 tokens (~211/item across 2 items; 2 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 2 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 3 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
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 80 to 83. That category is still filling its 30-day observation window: 24 days of observed history at the previous scan, 25 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 73 to 77. That category is still filling its 30-day observation window: 22 days of observed history at the previous scan, 23 at this one. The score rises as the window fills, whether or not the server changes.
- 30 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.
- 28 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.
- 26 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.
- 24 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 37 to 40. That category is still filling its 30-day observation window: 11 days of observed history at the previous scan, 12 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 30 to 33. That category is still filling its 30-day observation window: 9 days of observed history at the previous scan, 10 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 4 Nov 2026 · Probed https://faxonline.app/mcp/fax
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=faxonline.app | CN=WE1,O=Google Trust Services,C=US | 8 Oct 2026 | 6 Jan 2027 | ECDSA 256 | ECDSA-SHA256 | 3a95327309cc469d0ee3ef36b2bb360f |
| SANs: faxonline.app | ||||||
| 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 faxonline.app. — Secure
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| app. | present | 23684 | 8 | Verified |
| faxonline.app. | present | 2371 | 13 | Verified |
| faxonline.app. | 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 |
|---|---|
| x-content-type-options | nosniff |
| x-frame-options | deny |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://faxonline.app/mcp/fax | Verified | 200 | |
| http (plaintext) | http://faxonline.app/mcp/fax | HTTPS enforced | 301 | https://faxonline.app/mcp/fax |
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 →
get_fax_status Get Fax Status ~61
Check your prepared fax using its secret draft_token. Returns payment and delivery status. A processing fax has not yet been delivered. Poll no more than once every 15 seconds.
| Name | Type | Req | Description |
|---|---|---|---|
| draft_token | string | yes | The private token used in prepare_fax. |
No output schema declared.
No examples provided.
prepare_fax Prepare Fax ~243
Prepare one PDF fax and return its price and Stripe checkout link. This stores the document but does not send or charge. Completing checkout authorizes sending to the displayed recipient. fax_number must be a US fax number: 10 digits (5155551234), optionally prefixed with 1 or +1 (E.164 such as +15155551234); common formatting such as (515) 555-1234 is accepted. Keep draft_token private and reuse it with identical inputs for retries.
| Name | Type | Req | Description |
|---|---|---|---|
| document_base64 | string | yes | Standard base64 of the PDF bytes, without a data URL prefix; maximum decoded size 10 MiB. |
| draft_token | string | yes | A secret, cryptographically random 64-character lowercase hex token. Reuse for retries and status checks. |
| string | yes | Email address for delivery notifications. | |
| fax_number | string | yes | US destination fax number: 10 digits (5155551234), optionally prefixed with 1 or +1 (+15155551234). Common formatting such as (515) 555-1234 is accepted. |
| filename | string | yes | PDF filename without directory paths. |
No output schema declared.
No examples provided.
How do I install the FaxOnline MCP server?
FaxOnline is a hosted endpoint at https://faxonline.app/mcp/fax, 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 · faxonline.app
claude mcp add --transport http abrudtkuhl-faxonline 'https://faxonline.app/mcp/fax'
What is the FaxOnline MCP server?
FaxOnline is an MCP server listed in the public MCP registry as io.github.abrudtkuhl/faxonline. Prepare and track US PDF faxes with user-approved checkout. No account or subscription. This page covers its hosted endpoint (https://faxonline.app/mcp/fax).
Is the FaxOnline MCP server safe to use?
FaxOnline scores 83 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 FaxOnline MCP server expose?
FaxOnline exposes 2 tools: prepare_fax, get_fax_status. Their descriptions and schemas cost roughly 304 tokens of context every time the server is loaded.
Does the FaxOnline MCP server require authentication?
No. We connected to FaxOnline without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the FaxOnline MCP server still maintained?
FaxOnline is still listed as active in the MCP registry. We last reached this channel on 4 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.