# FactStamp (remote · factstamp.agentrails.workers.dev)

Paid verification for agents: cited, dated answers with a signed receipt that verifies offline.

- Trust score: 58/100 (low)
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-10-01

## Components

- remote · `factstamp.agentrails.workers.dev`: 58/100 (this document), [markdown](https://verifymcp.io/servers/au-com-alpineai-factstamp/factstamp.md), [page](https://verifymcp.io/servers/au-com-alpineai-factstamp/factstamp)

## Channel facts

- Endpoint: `https://factstamp.agentrails.workers.dev/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `0.1.0`

## Trust breakdown

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. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-10-01.

- **Endpoint Security**: 46/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - Authorisation not fully verified: no authorisation is required to call this server, and 2 tool(s) never declared a destructiveHint. The MCP spec treats an absent hint as destructive by default, so we cannot call this surface safe.
  - HTTPS enforcement could not be verified: the plaintext port answered with HTTP 402, which proves neither a plaintext path nor enforcement.
  - HSTS check failed: the Strict-Transport-Security header is absent.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 66/100
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 1901 tokens (~190/item across 10 items; 10 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 10/100
  - Stability observed for 3 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% of tool parameters carry a description.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 10 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 10 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 60/100
  - Spec-recency check failed: implements MCP spec 2025-06-18; the latest is 2026-07-28.

## Install

### How do I install the FactStamp MCP server?

FactStamp is a hosted endpoint at https://factstamp.agentrails.workers.dev/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.

### Claude

```bash
claude mcp add --transport http au-com-alpineai-factstamp 'https://factstamp.agentrails.workers.dev/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "au-com-alpineai-factstamp": {
      "url": "https://factstamp.agentrails.workers.dev/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "au-com-alpineai-factstamp": {
      "type": "http",
      "url": "https://factstamp.agentrails.workers.dev/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.au-com-alpineai-factstamp]
url = "https://factstamp.agentrails.workers.dev/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "au-com-alpineai-factstamp": {
      "type": "remote",
      "url": "https://factstamp.agentrails.workers.dev/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add au-com-alpineai-factstamp --url 'https://factstamp.agentrails.workers.dev/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  au-com-alpineai-factstamp:
    url: "https://factstamp.agentrails.workers.dev/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "au-com-alpineai-factstamp": {
      "Transport": "http",
      "Url": "https://factstamp.agentrails.workers.dev/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add au-com-alpineai-factstamp -t streamable-http -u 'https://factstamp.agentrails.workers.dev/mcp'
```

### Other

```json
{
  "mcpServers": {
    "au-com-alpineai-factstamp": {
      "type": "http",
      "url": "https://factstamp.agentrails.workers.dev/mcp"
    }
  }
}
```

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-09-30 (score 58, 0)

- [security] Tool “verify_bulk” rewrote its description, which is the text the model reads
- [functional regression] Schema quality: 1464 → 1901
- [functional] New tool “check_document”
- [functional] New tool “watch_portfolio”

### 2026-09-29 (score 58, −8)

- [security regression] Authorization: partial → unverified
- [security] Tool “check_entity” rewrote its description, which is the text the model reads
- [security] Tool “check_figure” rewrote its description, which is the text the model reads
- [functional regression] Schema quality: pass → fail
- [functional improvement] Stability: unverified → 0.03
- [functional] New tool “verify_bulk”
- [functional] New tool “verify_citation”
- [functional] New tool “verify_package”
- [functional] New tool “watch_add”

### 2026-09-28 (score 66)

First indexed and scored.

## MCP tools (10)

### `list_series` (~32 tokens)

Free. What this engine covers, the publisher and as-of date behind each series, and the no-guess rule.

### `route_claim` (~58 tokens)

Free. Shows which series a claim would be routed to, the value and date extracted, and the signals behind the score. Returns NO verdict — pay for check_figure when you want one.

Input parameters:

- `claim` (string, required): The assertion to route.

### `check_figure` (~187 tokens)

Submit the dated figure you are about to act on. Returns verified, stale, contradicted or unknown, cited to the publisher's own series with its as-of date. Use before committing a number to a page, deck or decision. Not advice. Comes with an Ed25519-signed receipt covering the question, the verdict, the sources and the time, checkable offline against the published key at /.well-known/factstamp-issuer.json — so the check itself can be audited later by someone who was not here.

Input parameters:

- `claim` (string, required): The assertion to check, e.g. 'The RBA cash rate is 4.35% as at August 2026'.
- `series_id` (string): Optional. Name the series to bypass the rule-based router (see list_series). Use when you already know which series owns the number, or when routing was ambiguous.

### `check_entity` (~202 tokens)

Verify a legal entity: does this company exist, under which identifier and jurisdiction, and is its registration current? Cited to open primary registers (the GLEIF LEI index and US SEC EDGAR). Returns found, ambiguous, not_found or unknown; a near name match is never reported as a match. Not advice, not a credit check, not a sanction screen. Comes with an Ed25519-signed receipt covering the question, the verdict, the sources and the time, checkable offline against the published key at /.well-known/factstamp-issuer.json — so the check itself can be audited later by someone who was not here.

Input parameters:

- `jurisdiction` (string): Optional jurisdiction code to break ties, e.g. 'CA-ON', 'US-DE', 'AU'.
- `query` (string, required): The entity to verify: a legal name such as 'Shopify Inc.', an LEI, or a CIK. An identifier resolves exactly.

### `verify_citation` (~306 tokens)

Check a citation before you repeat it. Submit a DOI, an arXiv ID or a paper title: returns whether it exists, what it is (title, authors, year, container) and whether it has been retracted, cited to Crossref and arXiv. Optionally send what your document claims (title, authors, year, journal) and every field is compared one by one — a disagreement is reported as mismatch, never as verified. A near title match is never reported as verified; a title that is absent from both returns not_found. Not advice. Comes with an Ed25519-signed receipt covering the question, the verdict, the sources and the time, checkable offline against the published key at /.well-known/factstamp-issuer.json — so the check itself can be audited later by someone who was not here.

Input parameters:

- `claimed_authors` (array): The authors as your document lists them. Surnames are compared.
- `claimed_journal` (string): The journal or container as your document names it.
- `claimed_title` (string): The title exactly as your document quotes it, to have it compared against the record.
- `claimed_year` (integer): The year as your document states it. A difference of one year is tolerated.
- `query` (string, required): A DOI such as '10.1038/nature12373', an arXiv ID such as '1706.03762', or a paper title.

### `verify_package` (~198 tokens)

Check a dependency before you install it. Submit a package and version plus its ecosystem: returns whether that exact version exists, whether it is yanked or deprecated, and every advisory OSV lists against it. An invented version returns not_found with the real versions nearest to it, and an invented name returns the published names that look like it — which is the point, because that is how slopsquatting gets installed. Not a security audit. Comes with an Ed25519-signed receipt covering the question, the verdict, the sources and the time, checkable offline against the published key at /.well-known/factstamp-issuer.json — so the check itself can be audited later by someone who was not here.

Input parameters:

- `ecosystem` (string): Which registry to ask. Defaults to npm.
- `package` (string, required): The package to check, e.g. 'express', 'express@4.18.2' or '@scope/name'.

### `watch_add` (~256 tokens)

Watch a citation or a package version instead of checking it once. Send kind ('citation' or 'package') and the subject (a DOI, an arXiv ID or a title; or npm:express@4.18.2). The first check is answered immediately and signed, then re-checked daily for 30 days; every real change (a retraction, a new advisory, a yanked version) is recorded with its own signed receipt. Returns a read URL and a token shown once; optionally send an https webhook and each change is POSTed to it. Comes with an Ed25519-signed receipt covering the question, the verdict, the sources and the time, checkable offline against the published key at /.well-known/factstamp-issuer.json — so the check itself can be audited later by someone who was not here.

Input parameters:

- `kind` (string, required): What kind of subject this is.
- `subject` (string, required): The DOI, arXiv ID or title to watch; for a package, 'express@4.18.2' or 'npm:express@4.18.2'.
- `webhook` (string): Optional https URL: each recorded change is POSTed there as JSON.

### `watch_portfolio` (~197 tokens)

Watch a whole list instead of one reference at a time: up to 25 citations or package versions re-checked every day for 30 days under one token. US$5 a portfolio — 20 cents a reference, under a cent a check — and the first check on every reference is answered and signed immediately. Each real change carries its own signed receipt, and nothing is sent when nothing changed. Returns a read URL and a token shown once. Comes with an Ed25519-signed receipt covering the question, the verdict, the sources and the time, checkable offline against the published key at /.well-known/factstamp-issuer.json — so the check itself can be audited later by someone who was not here.

Input parameters:

- `items` (array, required): Up to 25 references. A repeated reference is charged once.
- `webhook` (string): Optional https URL: each recorded change on any reference is POSTed there as JSON.

### `verify_bulk` (~226 tokens)

Check a whole list in one call: a bibliography or a dependency manifest. Send items[] of {tool, input} or the citations[]/packages[] shorthand. Up to 12 items at a flat US$0.12 on this door; longer lists pay 0.016667 an item on the pack-funded HTTP door (POST /bulk, up to 25 items). Every item is answered by the same door that answers a single call, so the verdicts cannot disagree. Comes with an Ed25519-signed receipt covering the question, the verdict, the sources and the time, checkable offline against the published key at /.well-known/factstamp-issuer.json — so the check itself can be audited later by someone who was not here.

Input parameters:

- `citations` (array): Shorthand: DOIs, arXiv IDs or titles, each checked as a citation.
- `items` (array): Explicit form: each item names its door and its input.
- `packages` (array): Shorthand: package versions such as 'express@4.18.2'.

### `check_document` (~239 tokens)

Check a whole document in one call: the claims that can be verified against a primary source, each answered by the door that owns it with its own signed receipt, plus one receipt over the document. Extraction is mechanical, so the claim list and the count are reproducible from your document alone — nothing is inferred. This rail answers the first 5 claims for a flat US$0.25 (5 cents a claim); a better-funded document goes to the pack-funded HTTP door (POST /document, up to 25 claims at the same 5 cents a claim), whose free preview lists the claims and the price before anything is charged — use it first if you are unsure the document holds anything checkable. Comes with an Ed25519-signed receipt covering the question, the verdict, the sources and the time, checkable offline against the published key at /.well-known/factstamp-issuer.json — so the check itself can be audited later by someone who was not here.

Input parameters:

- `document` (string, required): The document text. Only sentences that name something we cover AND carry the value to check become claims; everything else is reported as considered.

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/au-com-alpineai-factstamp/factstamp#diagnostics

## Score history

- 2026-10-01: 58
- 2026-09-30: 58
- 2026-09-29: 58
- 2026-09-28: 66

## Common questions

### What is the FactStamp MCP server?

FactStamp is an MCP server listed in the public MCP registry as au.com.alpineai/factstamp. Paid verification for agents: cited, dated answers with a signed receipt that verifies offline. This page covers its hosted endpoint (https://factstamp.agentrails.workers.dev/mcp).

### Is the FactStamp MCP server safe to use?

FactStamp scores 58 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 FactStamp MCP server expose?

FactStamp exposes 10 tools: list_series, route_claim, check_figure, check_entity, verify_citation, and 5 more. Their descriptions and schemas cost roughly 1,901 tokens of context every time the server is loaded.

### Does the FactStamp MCP server require authentication?

No. We connected to FactStamp without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

### Is the FactStamp MCP server still maintained?

FactStamp is still listed as active in the MCP registry. We last reached this channel on 1 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

## Links

- Remote endpoint: https://factstamp.agentrails.workers.dev/mcp
- Changelog RSS feed: https://verifymcp.io/servers/au-com-alpineai-factstamp/factstamp.xml
- Changelog JSON feed: https://verifymcp.io/servers/au-com-alpineai-factstamp/factstamp.json
- HTML version of this page: https://verifymcp.io/servers/au-com-alpineai-factstamp/factstamp