# US Sales Tax Economic Nexus Check (remote · us-sales-tax-nexus.nerolabs.workers.dev)

Which US states must a remote seller register in for sales tax? Every state's nexus rule. Sourced.

- Trust score: 60/100 (medium)
- Change this week: +3
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-10-18

## Components

- remote · `us-sales-tax-nexus.nerolabs.workers.dev`: 60/100 (this document), [markdown](https://verifymcp.io/servers/nero-engine-us-sales-tax-nexus/us-sales-tax-nexus.md), [page](https://verifymcp.io/servers/nero-engine-us-sales-tax-nexus/us-sales-tax-nexus)

## Channel facts

- Endpoint: `https://us-sales-tax-nexus.nerolabs.workers.dev/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 2026-10-18.

- **Endpoint Security**: 46/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - Authorisation not fully verified: no authorisation is required to call this server, and 4 tool(s) never declared a destructiveHint. The MCP spec treats an absent hint as destructive by default, so we cannot call this surface safe.
  - 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 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**: 68/100
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 743 tokens (~185/item across 4 items; 4 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 23/100
  - Stability observed for 7 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.
- **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 5 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 60/100
  - Spec-recency check failed: implements MCP spec 2025-06-18; the latest is 2026-07-28.

## Install

### How do I install the US Sales Tax Economic Nexus Check MCP server?

US Sales Tax Economic Nexus Check is a hosted endpoint at https://us-sales-tax-nexus.nerolabs.workers.dev/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 nero-engine-us-sales-tax-nexus 'https://us-sales-tax-nexus.nerolabs.workers.dev/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "nero-engine-us-sales-tax-nexus": {
      "url": "https://us-sales-tax-nexus.nerolabs.workers.dev/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "nero-engine-us-sales-tax-nexus": {
      "type": "http",
      "url": "https://us-sales-tax-nexus.nerolabs.workers.dev/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.nero-engine-us-sales-tax-nexus]
url = "https://us-sales-tax-nexus.nerolabs.workers.dev/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "nero-engine-us-sales-tax-nexus": {
      "type": "remote",
      "url": "https://us-sales-tax-nexus.nerolabs.workers.dev/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add nero-engine-us-sales-tax-nexus --url 'https://us-sales-tax-nexus.nerolabs.workers.dev/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  nero-engine-us-sales-tax-nexus:
    url: "https://us-sales-tax-nexus.nerolabs.workers.dev/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "nero-engine-us-sales-tax-nexus": {
      "Transport": "http",
      "Url": "https://us-sales-tax-nexus.nerolabs.workers.dev/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add nero-engine-us-sales-tax-nexus -t streamable-http -u 'https://us-sales-tax-nexus.nerolabs.workers.dev/mcp'
```

### Other

```json
{
  "mcpServers": {
    "nero-engine-us-sales-tax-nexus": {
      "type": "http",
      "url": "https://us-sales-tax-nexus.nerolabs.workers.dev/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.

### 2026-10-17 (score 60, +1)

No change was recorded against any check on this day. Stability & Change Management went from 17 to 20. That category is still filling its 30-day observation window: 5 days of observed history at the previous scan, 6 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-15 (score 59, +1)

No change was recorded against any check on this day. Stability & Change Management went from 10 to 13. That category is still filling its 30-day observation window: 3 days of observed history at the previous scan, 4 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-13 (score 58, +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.

### 2026-10-12 (score 57, 0)

- [functional improvement] Stability: unverified → 0.03

### 2026-10-11 (score 57)

First indexed and scored.

## MCP tools (4)

### `list_capabilities` (~47 tokens)

Lists coverage (45 sales tax states plus DC, and the 5 states with no statewide sales tax), the date the data was last checked, and related Nero Labs Rules servers. Free.

### `check_economic_nexus` (~383 tokens)

Checks which US states a remote seller (no office, staff or stock in the state) must register in to collect sales tax, from its sales into each state. Give sales_by_state with the dollar sales and number of transactions (orders) per state, the period those figures cover, and whether they include sales made through marketplaces such as Amazon or Etsy. Returns states where the seller is over the economic nexus threshold (must register), states close to it (80 percent or more), states under it, and for each the threshold, the measurement period the state uses, what sales count (gross, retail or taxable only), whether marketplace sales count, when registration must happen, and the state revenue department source. Unclear cases give the SAFE answer (treated as over) with what it depends on. Free.

Input parameters:

- `date` (string): The date to check the rules on, YYYY-MM-DD. Defaults to today. Thresholds changed in several states; past dates use the rule then in force.
- `includes_marketplace_sales` (boolean): True (default) if the sales and transactions figures include sales made through marketplace facilitators. Many states exclude those sales when testing a remote seller's threshold.
- `period` (string): What period the figures cover: last_12_months (default), previous_calendar_year or current_calendar_year (year to date).
- `sales_by_state` (array, required): One item per state the seller ships into: {"state":"CA","sales":612000,"transactions":3400}. Optional per item: marketplace_sales and marketplace_transactions (the part made through marketplace facil…
- `show_all_states` (boolean): True to also list every sales tax state the seller did not report sales for. Default false.

### `list_nexus_thresholds` (~101 tokens)

Lists the economic nexus threshold of every US sales tax state (or one state) on a date: dollar and transaction thresholds, and/or logic, measurement period, what counts, marketplace rules, when to register and the official source. Also lists the states with no statewide sales tax. Free.

Input parameters:

- `date` (string): YYYY-MM-DD, default today.
- `state` (string): Optional two-letter code or name. All states when left out.

### `list_upcoming_nexus_changes` (~88 tokens)

Lists economic nexus threshold changes in a date window (for example states dropping the 200 transaction test), soonest first, with the old and new rule and source. Use a past from_date to see recent changes. Free.

Input parameters:

- `days` (integer): 1 to 1460, default 365.
- `from_date` (string): YYYY-MM-DD, default today.

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/nero-engine-us-sales-tax-nexus/us-sales-tax-nexus#diagnostics

## Score history

- 2026-10-18: 60
- 2026-10-17: 60
- 2026-10-16: 59
- 2026-10-15: 59
- 2026-10-14: 58
- 2026-10-13: 58
- 2026-10-12: 57
- 2026-10-11: 57

## Common questions

### What is the US Sales Tax Economic Nexus Check MCP server?

US Sales Tax Economic Nexus Check is an MCP server listed in the public MCP registry as io.github.Nero-Engine/us-sales-tax-nexus. Which US states must a remote seller register in for sales tax? Every state's nexus rule. Sourced. This page covers its hosted endpoint (https://us-sales-tax-nexus.nerolabs.workers.dev/mcp).

### Is the US Sales Tax Economic Nexus Check MCP server safe to use?

US Sales Tax Economic Nexus Check scores 60 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 US Sales Tax Economic Nexus Check MCP server expose?

US Sales Tax Economic Nexus Check exposes 4 tools: list_capabilities, check_economic_nexus, list_nexus_thresholds, list_upcoming_nexus_changes. Their descriptions and schemas cost roughly 619 tokens of context every time the server is loaded.

### Does the US Sales Tax Economic Nexus Check MCP server require authentication?

No. We connected to US Sales Tax Economic Nexus Check without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

### Is the US Sales Tax Economic Nexus Check MCP server still maintained?

US Sales Tax Economic Nexus Check is still listed as active in the MCP registry. We last reached this channel on 18 October 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://us-sales-tax-nexus.nerolabs.workers.dev/mcp
- Website: https://us-sales-tax-nexus.nerolabs.workers.dev/
- Changelog RSS feed: https://verifymcp.io/servers/nero-engine-us-sales-tax-nexus/us-sales-tax-nexus.xml
- Changelog JSON feed: https://verifymcp.io/servers/nero-engine-us-sales-tax-nexus/us-sales-tax-nexus.json
- HTML version of this page: https://verifymcp.io/servers/nero-engine-us-sales-tax-nexus/us-sales-tax-nexus