# Moltline Merchant Maths

> Processor fees, charge-to-net, invoice totals and proration. 3 of 6 tools free.

- name: com.moltlinestudio/merchant
- version: 1.2.0
- connection class: R0 (autonomous)
- trust: 84/100 flags: duplicate-repo
- quality: 91/100 (strong)
- owner: not claimed
- descriptor: https://api.protogrid.dev/v1/servers/com.moltlinestudio%2Fmerchant
- tools: https://api.protogrid.dev/v1/servers/com.moltlinestudio%2Fmerchant/tools

**An agent can connect right now, no human step.** Remote endpoint, no authentication, reachable on the last probe.

## Connection (mcpServers)

```json
{
  "mcpServers": {
    "merchant": {
      "type": "http",
      "url": "https://mcp.moltlinestudio.com/merchant"
    }
  }
}
```


## Trust

- hygiene: 60
- liveness: 99
- freshness: 85
- provenance: 85
- drivers: +repository +dns-namespace +website +reachable +uptime-97% ~updated-42d-ago -duplicate-repo(22 names)
- Derived from observable signals (official registry feed and our own credential-free probes); no code audit performed.

## Quality 91/100 (strong)

### protocol: 75 (weight 25)

- warn `protocol.modern`: newest supported version is 2025-11-25; 2026-07-28 not supported, older versions are deprecated until 2027-07-28
- n/a `protocol.stateless`: only applies to 2026-07-28 servers
- pass `protocol.transport`: streamable HTTP
- n/a `protocol.list_ttl`: only applies to 2026-07-28 servers

### authorization: n/a (weight 15)

- n/a `auth.prm`, `auth.as_metadata`, `auth.cimd`: no remote uses OAuth
- n/a `auth.secret_in_url`: no templated URL

### tool hygiene: 100 (weight 30)

- pass `tools.descriptions`: every tool has a description
- pass `tools.description_length`: descriptions are concise
- pass `tools.schemas`: every tool has an object input schema
- pass `tools.annotations`: 6 of 6 tools declare readOnlyHint or destructiveHint
- pass `tools.directory_hints`: every tool declares readOnlyHint, destructiveHint, idempotentHint and openWorldHint
- pass `tools.token_cost`: about 2,193 tokens to load every tool
- pass `tools.api_dump`: tools are not a one-to-one API dump

### stability: 100 (weight 15)

- pass `stability.changes`: no tool changes in 30 days
- pass `stability.rug_pull`: no tool changed its meaning under the same name

### dependencies: n/a (weight 15)

- n/a `deps.known_vulns`, `deps.mcp_sdk_version`, `deps.resolvable`: no npm or PyPI package

- tools: 6, about 2,193 tokens to load them all
- tool set hash: 7bf7471c00a5a8775da2f6a977f6a7d8
- badge: [![protogrid quality](https://protogrid.dev/badge/com.moltlinestudio/merchant.svg)](https://protogrid.dev/servers/com.moltlinestudio/merchant)
- Checks run on what our credential-free, read-only probes observe; tools are never called and no code audit is performed.

### Tool changes

_No tool definition changes recorded._

## Remotes

- https://mcp.moltlinestudio.com/merchant (streamable-http, auth none, reachable true, uptime30d 0.9652174)

## Packages

_none_

## Tools (6)

- `charge_to_net`: Compute the gross price to charge so you net a target after fees. FREE.

'Charge X to receive Y' after percentage + fixed processor fees.
Typical input {"net_target": 100, "pct_fee": 2.9, "fixed_fee": 0.30}
returns {"charge": 103.4, "fee": 3.4, "net": 100.0}.

The inverse of processor_fees - solves for gross from a target net. Use
when the payout is the fixed requirement. Not when the price is already
set. Errors: on invalid, missing, or malformed input this tool never raises a protocol error — it returns {"error": "<what is wrong and how to fix it>"} (for example {"error": "net_target > 0 and pct_fee < 100 required"}). Every call is read-only and idempotent, so after correcting the input it is always safe to retry.
- `discount_stack`: Stack discounts correctly: sequential vs additive comparison. PREMIUM (license).

The two methods differ — this shows both, the final price, and the true
total discount. Typical input {"price": 200, "discounts_pct": [20, 10]}
returns {"original": 200, "sequential_price": 144.0,
"sequential_total_discount_pct": 28.0, "additive_price": 140.0,
"difference": 4.0, "note": "..."}.

Use when more than one discount applies and the order changes the answer.
Not for a single discount inside an invoice (invoice_total). Errors: on invalid, missing, or malformed input this tool never raises a protocol error — it returns {"error": "<what is wrong and how to fix it>"} (for example {"error": "price > 0 and at least one discount required"}). Every call is read-only and idempotent, so after correcting the input it is always safe to retry.
- `installment_plan`: Split a total into an installment schedule with optional deposit. PREMIUM (license).

Rounding remainders land on the final payment so the schedule always
sums exactly. Typical input {"total": 1000, "installments": 3,
"deposit_pct": 10} returns {"deposit": 100.0, "payments": [300.0,
300.0, 300.0], "check_sum": 1000.0}.

Use when one total is paid across scheduled dates. Not for partial-period
adjustments (proration). Errors: on invalid, missing, or malformed input this tool never raises a protocol error — it returns {"error": "<what is wrong and how to fix it>"} (for example {"error": "total > 0 and 1-36 installments"}). Every call is read-only and idempotent, so after correcting the input it is always safe to retry.
- `invoice_total`: Total an invoice: per-line totals, subtotal, discount, tax, grand total. FREE.

Typical input {"line_items": [{"desc": "Design", "qty": 2,
"unit_price": 50}], "tax_pct": 8.5, "discount_pct": 10} returns
{"lines": [{"desc": "Design", "qty": 2, "unit_price": 50,
"line_total": 100.0}], "subtotal": 100.0, "discount": 10.0, "tax":
7.65, "total": 97.65}.

Use when several line items roll up with discount and tax. Not for one
transaction's fees (processor_fees) and not for spreading a total over
time (installment_plan). Errors: on invalid, missing, or malformed input this tool never raises a protocol error — it returns {"error": "<what is wrong and how to fix it>"} (for example {"error": "line_items must contain at least one item,"}). Every call is read-only and idempotent, so after correcting the input it is always safe to retry.
- `processor_fees`: Break down payment-processor fees: fee, net, and effective rate. FREE.

Uses editable presets for stripe/paypal/square/shopify (verify current
rates) or your own custom_pct + custom_fixed. Typical input {"amount":
1000, "processor": "stripe", "transactions": 10} returns {"gross":
1000, "fee": 32.0, "net": 968.0, "effective_rate_pct": 3.2, "note":
"..."}.

Use when the charge amount is known and the net payout is the question.
Not for the reverse: the gross needed to net a target is charge_to_net. Errors: on invalid, missing, or malformed input this tool never raises a protocol error — it returns {"error": "<what is wrong and how to fix it>"} (for example {"error": "amount must be > 0, transactions >= 1"}). Every call is read-only and idempotent, so after correcting the input it is always safe to retry.
- `proration`: Compute a prorated charge or refund for a partial billing period. PREMIUM (license).

Typical input {"amount_per_period": 90, "days_used": 10,
"days_in_period": 30} returns {"days_used": 10, "days_in_period": 30,
"prorated_charge": 30.0, "prorated_refund": 60.0, "answer": 30.0}.

Use when a plan starts, ends, or changes mid-period. Not for splitting a
full amount into scheduled payments (installment_plan). Errors: on invalid, missing, or malformed input this tool never raises a protocol error — it returns {"error": "<what is wrong and how to fix it>"} (for example {"error": "need amount > 0 and 0 <= days_used <= days_in_period"}). Every call is read-only and idempotent, so after correcting the input it is always safe to retry.