# Acorn Harness (remote · acornharness.com)

Configure, price and order custom XT30, XT30(2+2) and XT30 + JST GH wire harnesses.

- Trust score: 75/100 (medium)
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-05

## Components

- remote · `acornharness.com`: 75/100 (this document), [markdown](https://verifymcp.io/servers/com-acornharness-acorn/acornharness.md), [page](https://verifymcp.io/servers/com-acornharness-acorn/acornharness)

## Channel facts

- Endpoint: `https://acornharness.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**: 80/100
  - 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 is enforced; there's no plaintext access path.
  - The HSTS (Strict-Transport-Security) header is present.
  - 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**: 76/100
  - 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).
  - AI-judged instruction clarity (good).
  - Context-footprint check failed: tool/resource definitions use about 1179 tokens (~196/item across 6 items; 4 tools + 2 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 7/100
  - Stability observed for 2 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.
  - Structured output schemas are declared (75% 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 4 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 6 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.
  - Supports UI / widget rendering.

## Install

### How do I install the Acorn Harness MCP server?

Acorn Harness is a hosted endpoint at https://acornharness.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-acornharness-acorn 'https://acornharness.com/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "com-acornharness-acorn": {
      "url": "https://acornharness.com/mcp"
    }
  }
}
```

### VS Code

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

### Codex

```toml
[mcp_servers.com-acornharness-acorn]
url = "https://acornharness.com/mcp"
```

### opencode

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

### OpenClaw

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

### Hermes

```yaml
mcp_servers:
  com-acornharness-acorn:
    url: "https://acornharness.com/mcp"
```

### Netclaw

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

### Vellum

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

### Other

```json
{
  "mcpServers": {
    "com-acornharness-acorn": {
      "type": "http",
      "url": "https://acornharness.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.

### 2026-11-05 (score 75, +1)

No change was recorded against any check on this day. Stability & Change Management went from 3 to 7. That category is still filling its 30-day observation window: 1 days of observed history at the previous scan, 2 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-11-04 (score 74, 0)

- [functional improvement] Stability: unverified → 0.03

### 2026-11-03 (score 74)

First indexed and scored.

## MCP tools (4)

### `list_options` (~140 tokens)

List wire harness options

List every option for an Acorn Harness custom wire harness: connector types (XT30, XT30(2+2), XT30 + JST GH), wire length range, power gauges, end A and end B terminations (straight, right angle up/down, unterminated tinned leads on end B), wire colors, extras (twisted or crossed signal pair, JST GH end B), the rules for combining them, required_choices (with the question to ask the user for each), optional_choices and their defaults, pricing rules, lead time, shipping and returns. Call it when you need the allowed values; it takes no arguments and changes nothing.

### `quote_harness` (~212 tokens)

Quote wire harnesses

Price one or more custom wire harness designs exactly as acornharness.com checkout will. Returns, for each design, a picture (side view plus both ends' rear views, as the configurator draws it: show it to the user), a configurator_url that opens the design on the site, and defaults_applied. Every item needs connector, length_mm, power_gauge, end_a, end_b, quantity, or a complete design code / configurator URL in design. Items missing any of them are refused with the questions to ask: ask the user, don't guess, and ask about end A and end B separately. Colors, twisting, crossing and end_b_gh have defaults, listed in defaults_applied for you to tell the user. Volume discounts count every harness across all items. Prices exclude shipping (chosen at checkout) and sales tax. Nothing is ordered or saved.

Input parameters:

- `items` (array, required): 1–40 wire harness designs. Volume discounts count every harness across all items.

Output parameters:

- `currency` (string)
- `excludes` (string)
- `harnesses` (number): Total harnesses across all items
- `items` (array)
- `lead_time_business_days` (number)
- `next_volume_break`
- `shipping_options` (array)
- `ships_to` (string)
- `subtotal` (number): USD
- `volume_discount` (number): Fraction off every item, e.g. 0.1

### `create_order` (~252 tokens)

Create a wire harness order

Create an unpaid order for one or more wire harness designs and get a checkout_url on acornharness.com for the buyer. The buyer opens it to pay (card, Link or wallet, via Stripe) and enter the US shipping address and shipping speed; nothing is charged or built until they pay there, and the link expires after 24 hours. Quote first with quote_harness and confirm the design, quantity and price with the user before calling this. Never ask for or accept card numbers or other payment details in the conversation. Items take the same fields as quote_harness and must be just as complete: pass back each quoted item's config (or design) once the user has confirmed it.

Input parameters:

- `email` (string): Buyer's email, only if they gave it: prefills checkout; the receipt, invoice and tracking go there.
- `idempotency_key` (string): Any unique string. Retrying with the same key and the same items returns the same order instead of a second one.
- `items` (array, required): 1–40 wire harness designs. Volume discounts count every harness across all items.
- `reference` (string): Buyer's PO number or note, echoed back on the order.

Output parameters:

- `checkout_url` (string): Where the buyer pays, on acornharness.com
- `currency` (string)
- `excludes` (string)
- `expires_at` (string): checkout_url stops working after this time (ISO 8601)
- `harnesses` (number): Total harnesses across all items
- `id` (string): Order id; pass to get_order_status
- `items` (array)
- `lead_time_business_days` (number)
- `next_volume_break`
- `reference` (string|null)
- `shipping_options` (array)
- `ships_to` (string)
- `status` (string)
- `subtotal` (number): USD
- `volume_discount` (number): Fraction off every item, e.g. 0.1

### `get_order_status` (~108 tokens)

Get wire harness order status

Check an order by the id create_order returned (starts with cs_). Returns status: awaiting_payment (checkout_url still valid), payment_processing (a bank payment settling), payment_failed or expired (create a new order), or paid (built and shipped within 5 business days; tracking is emailed to the buyer), plus the charged totals. Never returns addresses or contact details.

Input parameters:

- `order_id` (string, required): The order id from create_order, e.g. cs_live_a1B2…

Output parameters:

- `checkout_url` (string): Only while awaiting_payment
- `created` (string)
- `currency` (string)
- `discount` (number): USD
- `expires_at` (string)
- `fulfillment` (string|null)
- `harnesses` (number)
- `id` (string)
- `items` (array)
- `reference` (string|null)
- `shipping`
- `status` (string)
- `subtotal` (number): USD
- `tax` (number): USD
- `total` (number): USD

## Diagnostics

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

## Score history

- 2026-11-05: 75
- 2026-11-04: 74
- 2026-11-03: 74

## Common questions

### What is the Acorn Harness MCP server?

Acorn Harness is an MCP server listed in the public MCP registry as com.acornharness/acorn. Configure, price and order custom XT30, XT30(2+2) and XT30 + JST GH wire harnesses. This page covers its hosted endpoint (https://acornharness.com/mcp).

### Is the Acorn Harness MCP server safe to use?

Acorn Harness scores 75 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 Acorn Harness MCP server expose?

Acorn Harness exposes 4 tools: list_options, quote_harness, create_order, get_order_status. Their descriptions and schemas cost roughly 712 tokens of context every time the server is loaded.

### Does the Acorn Harness MCP server require authentication?

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

### Is the Acorn Harness MCP server still maintained?

Acorn Harness 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://acornharness.com/mcp
- Repository: https://github.com/almond-bot/acorn-plugins
- Website: https://acornharness.com/developers#ai
- Changelog RSS feed: https://verifymcp.io/servers/com-acornharness-acorn/acornharness.xml
- Changelog JSON feed: https://verifymcp.io/servers/com-acornharness-acorn/acornharness.json
- HTML version of this page: https://verifymcp.io/servers/com-acornharness-acorn/acornharness