# MAC Address Lookup (remote · mac.jasontally.com)

Find the organization behind a MAC address or OUI prefix in the IEEE registries. No auth, no key.

- Trust score: 83/100 (high trust)
- Change this week: +1
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-05

## Components

- remote · `mac.jasontally.com`: 83/100 (this document), [markdown](https://verifymcp.io/servers/com-jasontally-mac-mcp/mac.md), [page](https://verifymcp.io/servers/com-jasontally-mac-mcp/mac)

## Channel facts

- Endpoint: `https://mac.jasontally.com/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `1.0.0`

## 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 2026-11-05.

- **Endpoint Security**: 66/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - No authorisation is required to call this server. Every tool declares its destructiveHint and none is destructive, so open access doesn't expose one.
  - HTTPS enforcement could not be verified: the plaintext port answered with HTTP 405, which proves neither a plaintext path nor enforcement.
  - HSTS check failed: the Strict-Transport-Security header is absent.
  - DNSSEC is configured correctly; the domain's records validate against the full chain to the root.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 82/100
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 203 tokens (~203/item across 1 items; 1 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 100/100
  - No destabilizing schema changes in the last 30 days.
- **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.
  - Structured output schemas are declared (100% of tools); any adoption earns full credit.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 1 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 2 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a current MCP spec version (2026-07-28).

## Install

### How do I install the MAC Address Lookup MCP server?

MAC Address Lookup is a hosted endpoint at https://mac.jasontally.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.

### Claude

```bash
claude mcp add --transport http com-jasontally-mac-mcp 'https://mac.jasontally.com/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "com-jasontally-mac-mcp": {
      "url": "https://mac.jasontally.com/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "com-jasontally-mac-mcp": {
      "type": "http",
      "url": "https://mac.jasontally.com/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.com-jasontally-mac-mcp]
url = "https://mac.jasontally.com/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "com-jasontally-mac-mcp": {
      "type": "remote",
      "url": "https://mac.jasontally.com/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add com-jasontally-mac-mcp --url 'https://mac.jasontally.com/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  com-jasontally-mac-mcp:
    url: "https://mac.jasontally.com/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "com-jasontally-mac-mcp": {
      "Transport": "http",
      "Url": "https://mac.jasontally.com/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add com-jasontally-mac-mcp -t streamable-http -u 'https://mac.jasontally.com/mcp'
```

### Other

```json
{
  "mcpServers": {
    "com-jasontally-mac-mcp": {
      "type": "http",
      "url": "https://mac.jasontally.com/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.

### 2026-11-01 (score 83, 0)

- [security] Stability: 0.97 → pass

### 2026-10-31 (score 83, +1)

No change was recorded against any check on this day. Stability & Change Management went from 93 to 97. That category is still filling its 30-day observation window: 28 days of observed history at the previous scan, 29 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-29 (score 82, +1)

No change was recorded against any check on this day. Stability & Change Management went from 87 to 90. That category is still filling its 30-day observation window: 26 days of observed history at the previous scan, 27 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-27 (score 81, +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.

### 2026-10-25 (score 80, +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.

### 2026-10-22 (score 79, +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.

### 2026-10-20 (score 78, +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.

### 2026-10-18 (score 77, +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.

## MCP tools (1)

### `lookup` (~133 tokens)

Look up a MAC address or OUI prefix

Resolve a MAC address or OUI prefix to its registered organization using longest-prefix match across the MA-L, MA-M, MA-S, IAB, and CID registries. Reports the block type, address count, registration country, and a link to the full record page. Randomized and locally administered addresses usually have no registered organization.

Input parameters:

- `mac` (string, required): MAC address or OUI prefix, 6 to 12 hex characters. Accepts colon, hyphen, Cisco dot, or plain hex, for example 8C:1F:64:AF:A4:B2 or 8C1F64.

Output parameters:

- `addressCount` (number|null): Addresses in the matched block.
- `blockType` (string|null): MA-L, MA-M, MA-S, IAB, or CID.
- `country` (string|null): ISO 3166-1 alpha-2 registration country.
- `locallyAdministered` (boolean): The bit pattern marks the address locally administered, which usually means a randomized or virtual-machine address.
- `multicast` (boolean): The bit pattern marks the address a multicast group.
- `orgName` (string|null): Registered organization name.
- `prefix` (string|null): Longest registered prefix that matched.
- `query` (string): The normalized query, colon-separated.
- `url` (string): Record page on https://mac.jasontally.com.

## Diagnostics

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

## Score history

- 2026-11-05: 83
- 2026-11-04: 83
- 2026-11-03: 83
- 2026-11-02: 83
- 2026-11-01: 83
- 2026-10-31: 83
- 2026-10-30: 82
- 2026-10-29: 82
- 2026-10-28: 81
- 2026-10-27: 81
- 2026-10-26: 80
- 2026-10-25: 80
- 2026-10-24: 79
- 2026-10-23: 79
- 2026-10-22: 79
- 2026-10-21: 78
- 2026-10-20: 78
- 2026-10-19: 77
- 2026-10-18: 77
- 2026-10-17: 76
- 2026-10-16: 76
- 2026-10-15: 75
- 2026-10-14: 75
- 2026-10-13: 74
- 2026-10-12: 74
- 2026-10-10: 73
- 2026-10-09: 72
- 2026-10-07: 72
- 2026-10-06: 71
- 2026-10-04: 70

## Common questions

### What is the MAC Address Lookup MCP server?

MAC Address Lookup is an MCP server listed in the public MCP registry as com.jasontally.mac/mcp. Find the organization behind a MAC address or OUI prefix in the IEEE registries. No auth, no key. This page covers its hosted endpoint (https://mac.jasontally.com/mcp).

### Is the MAC Address Lookup MCP server safe to use?

MAC Address Lookup 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 MAC Address Lookup MCP server expose?

MAC Address Lookup exposes 1 tool: lookup. Their descriptions and schemas cost roughly 133 tokens of context every time the server is loaded.

### Does the MAC Address Lookup MCP server require authentication?

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

### Is the MAC Address Lookup MCP server still maintained?

MAC Address Lookup is still listed as active in the MCP registry. We last reached this channel on 5 November 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://mac.jasontally.com/mcp
- Repository: https://github.com/jasontally/mac-address-lookup
- Website: https://mac.jasontally.com/
- Changelog RSS feed: https://verifymcp.io/servers/com-jasontally-mac-mcp/mac.xml
- Changelog JSON feed: https://verifymcp.io/servers/com-jasontally-mac-mcp/mac.json
- HTML version of this page: https://verifymcp.io/servers/com-jasontally-mac-mcp/mac