# Postio — UK Address, Postcode, Email & Phone Validation (npm · @postio/mcp)

Validate UK addresses, postcodes, emails and phone numbers — Royal Mail PAF, live SMTP and HLR.

- Trust score: 70/100 (medium)
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-08-17

## Components

- npm · `@postio/mcp`: 70/100 (this document), [markdown](https://verifymcp.io/servers/uk-co-postio-postcode-address-validation/postio-mcp.md), [page](https://verifymcp.io/servers/uk-co-postio-postcode-address-validation/postio-mcp)

## Channel facts

- Registry: `npm`
- Package: `@postio/mcp`
- Version: `0.1.4`
- Transport: `stdio`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, 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 2026-08-17.

- **Supply Chain Security**: 98/100
  - No malware found by supply-chain analysis.
  - No known CVEs affecting this package version or its production dependencies.
  - No install/post-install scripts declared.
  - 30 of 97 dependencies flagged as unhealthy.
- **Provenance & Transparency**: 45/100
  - Source repository is publicly reachable at the declared URL.
  - Provenance check failed: no build-provenance attestation is published.
  - Clear OSI-approved license (MIT).
  - Actively maintained (last published 2 days ago).
  - Disclosure check failed: no security disclosure policy was found in the source repository.
- **Schema Quality & AI Usability**: 82/100
  - AI-judged instruction clarity (excellent).
  - Tool/resource definitions use about 509 tokens (~84/item across 6 items; 6 tools + 0 resources), lean.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 0/100
  - Stability not yet verified: not enough scan history yet (needs a 30-day window).
- **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.
- **Capabilities**: 100/100
  - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.

**Unverified: 1 category.** A category scored 0 because we could not verify it: a data source with nothing on this package, evidence we could not reach, or a check we could not run. We only credit what we can confirm.

## Install

### Claude

```bash
claude mcp add uk-co-postio-postcode-address-validation -- npx -y @postio/mcp
```

### Codex

```bash
codex mcp add uk-co-postio-postcode-address-validation -- npx -y @postio/mcp
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "uk-co-postio-postcode-address-validation": {
      "type": "local",
      "command": [
        "npx",
        "-y",
        "@postio/mcp"
      ],
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add uk-co-postio-postcode-address-validation --command npx --arg -y --arg @postio/mcp
```

### Hermes

```yaml
mcp_servers:
  uk-co-postio-postcode-address-validation:
    command: "npx"
    args: ["-y", "@postio/mcp"]
```

### Other

```json
{
  "mcpServers": {
    "uk-co-postio-postcode-address-validation": {
      "command": "npx",
      "args": [
        "-y",
        "@postio/mcp"
      ]
    }
  }
}
```

## 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.

### 2026-08-17 (score 70, 0)

- [functional regression] Security disclosure: unverified → fail

### 2026-08-16 (score 70, 0)

- [functional regression] Security disclosure: fail → unverified

### 2026-08-14 (score 70)

First indexed and scored.

## MCP tools (6)

### `postio_address_search` (~118 tokens)

Search UK addresses by free-form text — building, street, postcode, organisation, or any combination. Returns a list of suggestions, each with a UDPRN (Royal Mail's per-address ID). Pass a chosen UDPRN to `postio_udprn_lookup` to fetch the full record. Free / non-billable.

Input parameters:

- `max_results` (integer): Max results to return. Default 10, max 50.
- `query` (string, required): Search string. Free-form: building, street, postcode, organisation.

### `postio_postcode_lookup` (~91 tokens)

Return every PAF delivery point at a UK postcode, ordered by building number. Whitespace and case are normalised. Billable on a hit; valid postcodes with no delivery points return an empty list and are not charged.

Input parameters:

- `max_results` (integer): Max results. Default 100.
- `postcode` (string, required): UK postcode, e.g. 'W1G 8YW'.

### `postio_udprn_lookup` (~78 tokens)

Look up a single UK delivery point by its UDPRN (Royal Mail's stable per-address ID). Use this after `postio_address_search` to fetch the full record for a chosen suggestion. Billable on a hit; misses (404) are not charged.

Input parameters:

- `udprn` (required): Unique Delivery Point Reference Number.

### `postio_email_validate` (~88 tokens)

Validate an email address: syntax (RFC 5322), typo correction (gnail→gmail), classification (disposable, role, free provider), MX lookup, and live SMTP mailbox probe. Returns an aggregated `deliverability` verdict (deliverable / undeliverable / risky / unknown / invalid) plus every signal independently.

Input parameters:

- `email` (string, required): Email address to validate.

### `postio_phone_validate` (~91 tokens)

Parse a phone number with libphonenumber and run a live HLR (Home Location Register) lookup. Returns current carrier (post-porting), original carrier, ported flag, reachability, MCC/MNC. Pass numbers in E.164 (`+447700900123`) for unambiguous results.

Input parameters:

- `number` (string, required): Phone number — E.164, international, or national format.

### `postio_connect` (~43 tokens)

Free key/health probe. Returns 200 if the API key is active and the upstream search service is reachable. Useful as a smoke test or to warm the worker.

## Diagnostics

Captured diagnostic sections: Provenance, Dependencies. The full working is on the page: https://verifymcp.io/servers/uk-co-postio-postcode-address-validation/postio-mcp#diagnostics

## Score history

- 2026-08-17: 70
- 2026-08-16: 70
- 2026-08-15: 70
- 2026-08-14: 70

## Links

- npm package: https://www.npmjs.com/package/@postio/mcp
- Socket report: https://socket.dev/npm/package/@postio/mcp
- Repository: https://github.com/postio-uk/postio-integrations
- Website: https://postio.co.uk/integrations/mcp
- Changelog RSS feed: https://verifymcp.io/servers/uk-co-postio-postcode-address-validation/postio-mcp.xml
- Changelog JSON feed: https://verifymcp.io/servers/uk-co-postio-postcode-address-validation/postio-mcp.json
- HTML version of this page: https://verifymcp.io/servers/uk-co-postio-postcode-address-validation/postio-mcp