fourzerotwo
REMOTE · FOURZEROTWO.SI
400+ data APIs for agents: UK companies, property, trade, tenders, recalls, sanctions. Free tier
Available components
Last scanned (22 hours ago)
Scores higher than 91% of remote servers
Reachable. Last reached 4 Nov 2026.
Category Search and Retrieval
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 Security80
- 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
- The HSTS (Strict-Transport-Security) header is present. View diagnostics → Pass
- 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 Usability80
- 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).Pass
- AI-judged instruction clarity (good).Pass
- Context-footprint check failed: tool/resource definitions use about 635 tokens (~127/item across 5 items; 3 tools + 2 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 Management77
- Stability observed for 23 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
- 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 3 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 5 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.
- 3 Nov 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 70 to 73. That category is still filling its 30-day observation window: 21 days of observed history at the previous scan, 22 at this one. The score rises as the window fills, whether or not the server changes.
- 1 Nov 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.
- 30 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.
- 28 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.
- 26 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.
- 23 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 33 to 37. That category is still filling its 30-day observation window: 10 days of observed history at the previous scan, 11 at this one. The score rises as the window fills, whether or not the server changes.
- 21 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 27 to 30. That category is still filling its 30-day observation window: 8 days of observed history at the previous scan, 9 at this one. The score rises as the window fills, whether or not the server changes.
- 19 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 20 to 23. That category is still filling its 30-day observation window: 6 days of observed history at the previous scan, 7 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://fourzerotwo.si/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=fourzerotwo.si | CN=WE1,O=Google Trust Services,C=US | 10 Oct 2026 | 8 Jan 2027 | ECDSA 256 | ECDSA-SHA256 | 7083f50b7ee269bb0ef93ba441295bdf |
| SANs: fourzerotwo.si | ||||||
| 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 insecure
Validation of fourzerotwo.si. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| si. | present | 42378 | 13 | Verified |
| fourzerotwo.si. | 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 |
| Header | Value |
|---|---|
| strict-transport-security | max-age=31536000; includeSubDomains |
| 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://fourzerotwo.si/mcp | Verified | 200 | |
| http (plaintext) | http://fourzerotwo.si/mcp | HTTPS enforced | 301 | https://fourzerotwo.si/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 →
call_api Call a data API ~178
Run one endpoint by the tool name that search_apis returned, with that endpoint's parameters, and get its data back as JSON (with source and licence attribution). Endpoints with free_tier "free" or "sample" cost nothing within the daily allowance (100 calls/day anonymously, 500 with a free key). Otherwise the result is a payment request: pay in USDC via x402 and retry with _meta["x402/payment"]. Invalid arguments are rejected before any charge, and failed upstream calls are never charged.
| Name | Type | Req | Description |
|---|---|---|---|
| arguments | object | – | The endpoint's parameters as listed in search_apis results, e.g. {"postcode": "SW1A 1AA"}. |
| tool | string | yes | Endpoint tool name from search_apis, e.g. "uk-postcodes__lookup" or "sanctions__screen". |
Structured output declared, but exposes no named fields.
No examples provided.
list_apis List API groups ~71
Overview of every API group in the catalog: name, category, summary, number of endpoints and whether it has a free tier. Always free to call. Use it to browse; use search_apis to find a specific endpoint.
| Name | Type | Req | Description |
|---|---|---|---|
| category | string | – | Optional category filter, e.g. "property". |
| Name | Type | Req | Description |
|---|---|---|---|
| apis | array | yes | – |
| categories | array | yes | – |
No examples provided.
search_apis Search data APIs ~200
Find the right data endpoint for a task. Searches 500+ endpoints (UK legislation, Companies House, property prices, sanctions lists, vehicle tax, weather, earthquakes, arXiv/PubMed/Crossref papers, IP geolocation, GB electricity, ONS/World Bank/ECB economics, and more) by keyword and returns each match's tool name, parameters, price and free_tier. Always free to call. Next step: pass a returned tool name to call_api.
| Name | Type | Req | Description |
|---|---|---|---|
| category | string | – | Optional category filter, e.g. "legal", "property", "finance", "research", "energy", "network". See list_apis for all categories. |
| limit | integer | – | Maximum results (default 20). |
| query | string | – | Keywords describing the data you need; every word must match. Examples: "postcode", "sanctions screen", "sold prices", "earthquake", "bank holiday". |
| Name | Type | Req | Description |
|---|---|---|---|
| results | array | yes | – |
| total | integer | yes | – |
No examples provided.
How do I install the fourzerotwo MCP server?
fourzerotwo is a hosted endpoint at https://fourzerotwo.si/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 · fourzerotwo.si
claude mcp add --transport http si-fourzerotwo-data 'https://fourzerotwo.si/mcp'
What is the fourzerotwo MCP server?
fourzerotwo is an MCP server listed in the public MCP registry as si.fourzerotwo/data. 400+ data APIs for agents: UK companies, property, trade, tenders, recalls, sanctions. Free tier. This page covers its hosted endpoint (https://fourzerotwo.si/mcp).
Is the fourzerotwo MCP server safe to use?
fourzerotwo scores 85 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 fourzerotwo MCP server expose?
fourzerotwo exposes 3 tools: search_apis, list_apis, call_api. Their descriptions and schemas cost roughly 449 tokens of context every time the server is loaded.
Does the fourzerotwo MCP server require authentication?
No. We connected to fourzerotwo without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the fourzerotwo MCP server still maintained?
fourzerotwo 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.