FactReason
REMOTE · WWW.FACTREASON.COM
Check exact npm/PyPI upgrades for evidence-backed breaking changes; query APIs and components.
Available components
Last scanned (18 hours ago)
Scores higher than 90% of remote servers
Reachable. Last reached 16 Oct 2026.
Category Code Search and Documentation
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 Security74
- 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 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 Usability72
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 2227 tokens (~202/item across 11 items; 11 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
- Structured output schemas are declared (100% of tools); any adoption earns full credit.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 11 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 12 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
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 Oct 26 0
- Schema quality: 147 → 202 ▼ functional
- 28 Sept 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
- 25 Sept 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
- 24 Sept 26 0
- Stability: 0.97 → pass security
- 23 Sept 26 0
- Stability: pass → 0.97 functional
- 21 Sept 26 0
- Stability: 0.97 → pass security
- 20 Sept 26 0
- Stability: pass → 0.97 functional
- 13 Sept 26 83
- Stability: 0.97 → pass security
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 16 Oct 2026 · Probed https://www.factreason.com/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=www.factreason.com | CN=YE1,O=Let's Encrypt,C=US | 13 Oct 2026 | 11 Jan 2027 | ECDSA 256 | ECDSA-SHA384 | 6fbc4de7ea2228da7a33e32168d1b20d902 |
| SANs: www.factreason.com | ||||||
| CN=YE1,O=Let's Encrypt,C=US (CA) | CN=Root YE,O=ISRG,C=US | 3 Sept 2025 | 2 Sept 2028 | ECDSA 384 | ECDSA-SHA384 | 5ddd70dd31f801c85c186a7a04b80afe |
| CN=Root YE,O=ISRG,C=US (CA) | CN=ISRG Root X2,O=Internet Security Research Group,C=US | 13 May 2026 | 2 Sept 2032 | ECDSA 384 | ECDSA-SHA384 | 872165fc34b6e5fba8add5b3705fb53a |
| CN=ISRG Root X2,O=Internet Security Research Group,C=US (CA) | CN=ISRG Root X1,O=Internet Security Research Group,C=US | 13 May 2026 | 2 Sept 2032 | ECDSA 384 | SHA256-RSA | 6c8f1dc727c7117f7baf853ac980f9cd |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of www.factreason.com. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| com. | present | 19718 | 13 | Verified |
| factreason.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://www.factreason.com/mcp | Verified | 200 | |
| http (plaintext) | http://www.factreason.com/mcp | HTTPS enforced | 301 | https://www.factreason.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 →
factreason_api_breaking_changes API breaking changes ~162
Compare two versions of a third-party API and return breaking changes, including removed endpoints, parameter type changes, removed request body fields, and migration guides. Use factreason_package_upgrade_advisory for npm or PyPI packages.
| Name | Type | Req | Description |
|---|---|---|---|
| apiKey | string | – | Your FactReason API key, from factreason_create_key. Pass it here when your MCP client cannot set the Authorization: Bearer header on this connection; if the header is set, omit this. Never pass a ke… |
| fromVersion | string | – | Optional exact version currently targeted |
| service | string | yes | Third-party API service, e.g. "Stripe" or "OpenAI" |
| toVersion | string | – | Optional exact version being evaluated |
| Name | Type | Req | Description |
|---|---|---|---|
| alternatives | array | – | – |
| billed | boolean | – | – |
| changeCount | number | – | – |
| changes | array | – | – |
| found | boolean | – | – |
| meaning | string | – | – |
| message | string | – | – |
| service | string | – | – |
| suggestion | string | – | – |
No examples provided.
factreason_api_schema API schema search ~169
Search exact request and response schemas for third-party API endpoints. Pass service alone to list its indexed endpoints, add query to narrow by path or operation, or use query alone across services; returns matches or nearest services. Uses metered access and does not modify source data. Prefer factreason_integration_brief for one callable request.
| Name | Type | Req | Description |
|---|---|---|---|
| apiKey | string | – | Your FactReason API key, from factreason_create_key. Pass it here when your MCP client cannot set the Authorization: Bearer header on this connection; if the header is set, omit this. Never pass a ke… |
| query | string | – | Optional endpoint path or operation, e.g. "payment_intents" |
| service | string | – | Optional service filter, e.g. "Stripe" |
| Name | Type | Req | Description |
|---|---|---|---|
| found | boolean | – | – |
| hint | string | – | – |
| message | string | – | – |
| nearestServices | array | – | – |
| results | array | – | – |
| totalMatched | number | – | – |
No examples provided.
factreason_auth_playbook Auth and error playbook ~156
Get publisher-declared authentication schemes, scopes, rate-limit headers, and error codes for one third-party API. Returns a structured playbook or nearest service suggestions, and marks undocumented details as unstated rather than guessing. Uses metered access. Prefer factreason_integration_brief when assembling a complete API call.
| Name | Type | Req | Description |
|---|---|---|---|
| apiKey | string | – | Your FactReason API key, from factreason_create_key. Pass it here when your MCP client cannot set the Authorization: Bearer header on this connection; if the header is set, omit this. Never pass a ke… |
| service | string | yes | Third-party API service, e.g. "Stripe", "Twilio", or "Cloudflare" |
| Name | Type | Req | Description |
|---|---|---|---|
| compact | object | – | – |
| found | boolean | – | – |
| message | string | – | – |
| nearestServices | array | – | – |
| playbook | object | – | – |
No examples provided.
factreason_component_spec Component specification ~217
Look up electronics component pin assignments, voltage range, package, and alternatives. Pass exact partNumber for one component or query for a capability search; partNumber takes precedence if both are supplied. For exact lookups, set responseFormat="compact" for tokenizer-measured context savings; the backward-compatible default is "full". Uses metered access and returns matches or suggestions. Confirm critical values against the manufacturer datasheet.
| Name | Type | Req | Description |
|---|---|---|---|
| apiKey | string | – | Your FactReason API key, from factreason_create_key. Pass it here when your MCP client cannot set the Authorization: Bearer header on this connection; if the header is set, omit this. Never pass a ke… |
| partNumber | string | – | Exact part number, e.g. "STM32F401RE" |
| query | string | – | Free-text capability search, e.g. "3.3V ARM MCU with SPI" |
| responseFormat | string | – | Use compact for an exact part lookup; full preserves the legacy data response |
| Name | Type | Req | Description |
|---|---|---|---|
| compact | string | – | – |
| data | object | – | – |
| found | boolean | – | – |
| hint | string | – | – |
| message | string | – | – |
| nearestMatches | array | – | – |
| partNumber | string | – | – |
| provenance | object | – | – |
| qualityScore | number | – | – |
| results | array | – | – |
| tokenMetrics | object | – | – |
| totalMatched | number | – | – |
No examples provided.
factreason_create_key Create an API key ~179
Get a FactReason API key for yourself, instantly, with no human, no signup and no card. Returns a key carrying one-off trial credit that you can spend immediately on any tool. CALL THIS FIRST if you have no key, or as soon as any FactReason tool returns HTTP 402 Payment Required — then retry the original call with the key, passed as that tool's apiKey argument (or as an Authorization: Bearer header if your client can set one). The tool is free and is never metered. Supplying an email is optional and only affects whether trial credit is granted; a key is always issued either way.
| Name | Type | Req | Description |
|---|---|---|---|
| string | – | Optional contact address for the key owner. Improves the chance of receiving trial credit and lets the operator reach you about corrections. Never send a human's address without their agreement. |
| Name | Type | Req | Description |
|---|---|---|---|
| apiKey | string | – | – |
| created | boolean | – | – |
| error | string | – | – |
| howToUse | string | – | – |
| note | string | – | – |
| topupUrl | string | – | – |
| trialCreditUsd | number | – | – |
| trialGranted | boolean | – | – |
No examples provided.
factreason_create_topup_link Create a top-up link ~170
Create a Stripe Checkout URL for adding prepaid credit to the calling Bearer API key. This creates an external checkout session but does not charge a card. You CANNOT COMPLETE THE PAYMENT YOURSELF, so return the URL to a human, and credit is applied only after they complete payment. Use after HTTP 402 or when balance is low; the tool itself is not metered.
| Name | Type | Req | Description |
|---|---|---|---|
| amountUsd | number | yes | Credit amount in USD; common blocks are 10, 50, and 200 |
| apiKey | string | – | Your FactReason API key, from factreason_create_key. Pass it here when your MCP client cannot set the Authorization: Bearer header on this connection; if the header is set, omit this. Never pass a ke… |
| Name | Type | Req | Description |
|---|---|---|---|
| amountUsd | number | – | – |
| balanceUrl | string | – | – |
| checkoutUrl | string | – | – |
| createKeyUrl | string | – | – |
| created | boolean | – | – |
| error | string | – | – |
| instructions | string | – | – |
No examples provided.
factreason_deprecation_scan Deprecation scan ~167
Scan publisher specifications for deprecated endpoints or parameters, sunset dates, and replacement operations. Omit filters for the catalogue-wide view, pass service to limit one API, and add endpoints to check selected paths. Uses metered access when findings exist. Use factreason_api_breaking_changes for broader version-to-version changes.
| Name | Type | Req | Description |
|---|---|---|---|
| apiKey | string | – | Your FactReason API key, from factreason_create_key. Pass it here when your MCP client cannot set the Authorization: Bearer header on this connection; if the header is set, omit this. Never pass a ke… |
| endpoints | array | – | Optional endpoint paths to check within the selected service |
| service | string | – | Optional service filter, e.g. "Stripe" or "Twilio" |
| Name | Type | Req | Description |
|---|---|---|---|
| count | number | – | – |
| found | boolean | – | – |
| message | string | – | – |
| results | array | – | – |
No examples provided.
factreason_discover_api Discover an API ~153
Find third-party APIs for a capability when the provider is unknown. Supply a concise capability such as "sms" or "manage DNS"; returns ranked services, example endpoints, and a next step. Uses metered access. When the provider is already known, call factreason_integration_brief instead.
| Name | Type | Req | Description |
|---|---|---|---|
| apiKey | string | – | Your FactReason API key, from factreason_create_key. Pass it here when your MCP client cannot set the Authorization: Bearer header on this connection; if the header is set, omit this. Never pass a ke… |
| capability | string | yes | Capability to search for, e.g. "send an SMS" or "charge a card" |
| Name | Type | Req | Description |
|---|---|---|---|
| billed | boolean | – | – |
| capability | string | – | – |
| count | number | – | – |
| found | boolean | – | – |
| hint | string | – | – |
| message | string | – | – |
| nextStep | string | – | – |
| results | array | – | – |
No examples provided.
factreason_integration_brief Integration brief ~208
Compile one callable third-party API brief: base URL, auth scheme, required parameters and types, request body, and documented response codes. Service is required and endpoint optionally narrows the operation. Set responseFormat="compact" for tokenizer-measured context savings; the backward-compatible default returns the full brief plus compact form. Uses metered access. Prefer factreason_api_schema when exploring multiple endpoints.
| Name | Type | Req | Description |
|---|---|---|---|
| apiKey | string | – | Your FactReason API key, from factreason_create_key. Pass it here when your MCP client cannot set the Authorization: Bearer header on this connection; if the header is set, omit this. Never pass a ke… |
| endpoint | string | – | Optional path or operation fragment used to select one call |
| responseFormat | string | – | Use compact for the callable facts only; full preserves the legacy brief response |
| service | string | yes | Third-party API service, e.g. "Stripe" or "Twilio" |
| Name | Type | Req | Description |
|---|---|---|---|
| billed | boolean | – | – |
| brief | object | – | – |
| compact | string | – | – |
| found | boolean | – | – |
| hint | string | – | – |
| message | string | – | – |
| nearestServices | array | – | – |
| service | string | – | – |
| tokenMetrics | object | – | – |
No examples provided.
factreason_package_upgrade_advisory Package upgrade advisory ~284
Compare two exact published npm or PyPI versions and return publisher-declared registry metadata changes, including yanks, exports, module format, runtime floors, peers, and licences, with before/after evidence. Set responseFormat="compact" for tokenizer-measured context savings; the backward-compatible default is "full". This is a read-only metered lookup; misses are never billed and every API key carries one-off trial credit. Use it for package metadata; use factreason_api_breaking_changes for a third-party HTTP API, and consult changelogs for behavioural changes.
| Name | Type | Req | Description |
|---|---|---|---|
| apiKey | string | – | Your FactReason API key, from factreason_create_key. Pass it here when your MCP client cannot set the Authorization: Bearer header on this connection; if the header is set, omit this. Never pass a ke… |
| from | string | yes | Exact currently installed version, e.g. "4.1.2" |
| name | string | yes | Exact package name, e.g. "chalk" or "urllib3" |
| registry | string | yes | Registry containing both package versions |
| responseFormat | string | – | Use compact to remove repeated prose and fields while retaining evidence; full preserves the legacy response contract |
| to | string | yes | Exact target version, e.g. "5.0.0" |
| Name | Type | Req | Description |
|---|---|---|---|
| advisories | array | – | – |
| advisoryCount | number | – | – |
| billed | boolean | – | – |
| breakingCount | number | – | – |
| found | boolean | – | – |
| fromVersion | string | – | – |
| message | string | – | – |
| packageName | string | – | – |
| scope | string | – | – |
| toVersion | string | – | – |
| tokenMetrics | object | – | – |
No examples provided.
factreason_subscribe_spec_changes Watch a specification ~188
Create a persistent specification watch for one service; a Bearer API key is required and each key may hold up to 50 watches. Without webhookUrl, read future events from the polling endpoint; with a public HTTP(S) URL, FactReason sends signed POST callbacks after later spec changes. Duplicate or unsafe webhook registrations are rejected. This does not ingest a specification immediately.
| Name | Type | Req | Description |
|---|---|---|---|
| apiKey | string | – | Your FactReason API key, from factreason_create_key. Pass it here when your MCP client cannot set the Authorization: Bearer header on this connection; if the header is set, omit this. Never pass a ke… |
| serviceName | string | yes | Service name to watch, e.g. "Stripe" or "SendGrid" |
| webhookUrl | string | – | Optional public HTTP(S) URL for signed change callbacks; omit to poll |
| Name | Type | Req | Description |
|---|---|---|---|
| error | string | – | – |
| success | boolean | – | – |
| watch | object | – | – |
No examples provided.
How do I install the FactReason MCP server?
FactReason is a hosted endpoint at https://www.factreason.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 · www.factreason.com
claude mcp add --transport http factreason-factreason 'https://www.factreason.com/mcp'
What is the FactReason MCP server?
FactReason is an MCP server listed in the public MCP registry as io.github.factreason/factreason. Check exact npm/PyPI upgrades for evidence-backed breaking changes; query APIs and components. This page covers its hosted endpoint (https://www.factreason.com/mcp).
Is the FactReason MCP server safe to use?
FactReason 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 FactReason MCP server expose?
FactReason exposes 11 tools: factreason_package_upgrade_advisory, factreason_api_breaking_changes, factreason_api_schema, factreason_integration_brief, factreason_discover_api, and 6 more. Their descriptions and schemas cost roughly 2,053 tokens of context every time the server is loaded.
Does the FactReason MCP server require authentication?
No. We connected to FactReason without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the FactReason MCP server still maintained?
FactReason is still listed as active in the MCP registry. We last reached this channel on 16 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.