# io.github.evidai/agent-payment (npm · agent-payment-mcp)

Stripe-style USDC billing for any API. 8 free demo services no signup. Non-custodial.

- Trust score: 68/100 (medium)
- Change this week: +18
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-08-03

## Components

- npm · `agent-payment-mcp`: 68/100 (this document), [markdown](https://verifymcp.io/servers/evidai-agent-payment/agent-payment-mcp.md), [page](https://verifymcp.io/servers/evidai-agent-payment/agent-payment-mcp)

## Channel facts

- Registry: `npm`
- Package: `agent-payment-mcp`
- Version: `0.9.1`
- 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 2026-08-03.

- **Supply Chain Security**: 86/100
  - No malware found by supply-chain analysis.
  - Only part of the dependency tree could be resolved (94 of 98), so this covers what we could see, not the whole tree.
  - No install/post-install scripts declared.
  - Only part of the dependency tree could be resolved (94 of 98), so this covers what we could see, not the whole tree.
- **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 60 days ago).
  - Disclosure check failed: no security disclosure policy was found in the source repository.
- **Schema Quality & AI Usability**: 71/100
  - 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 1823 tokens (~303/item across 6 items; 6 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 27/100
  - Stability observed for 8 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.
- **Capabilities**: 100/100
  - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.

## Install

### Claude

```bash
claude mcp add evidai-agent-payment -- npx -y agent-payment-mcp
```

### Codex

```bash
codex mcp add evidai-agent-payment -- npx -y agent-payment-mcp
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "evidai-agent-payment": {
      "type": "local",
      "command": [
        "npx",
        "-y",
        "agent-payment-mcp"
      ],
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add evidai-agent-payment --command npx --arg -y --arg agent-payment-mcp
```

### Hermes

```yaml
mcp_servers:
  evidai-agent-payment:
    command: "npx"
    args: ["-y", "agent-payment-mcp"]
```

### Other

```json
{
  "mcpServers": {
    "evidai-agent-payment": {
      "command": "npx",
      "args": [
        "-y",
        "agent-payment-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.

### 2026-08-03 (score 68, +4)

- [functional improvement] Stability: unverified → 0.27

### 2026-08-02 (score 64, +40)

- [security regression] Provenance: unverified → fail
- [security improvement] Install scripts: unverified → pass
- [security improvement] Known CVEs: unverified → partial
- [security improvement] Malware scan: unverified → pass
- [security] Stability: Stability not yet verified: not enough scan history yet (needs a 30-day window).
- [functional regression] Schema quality: 100 → unverified
- [functional regression] Tool coverage: 100 → unverified
- [functional improvement] License: unverified → pass
- [functional improvement] Dependency health: unverified → partial
- [functional improvement] Maintenance: unverified → pass
- [functional improvement] MCP protocol: unverified → pass
- [functional improvement] Schema quality: unverified → good
- [functional] Licence: MIT

### 2026-08-01 (score 24, +18)

- [functional] We updated how we score, so this day's move reflects our rubric, not a change to the server

### 2026-07-31 (score 6, −44)

- [security regression] Malware scan: pass → unverified
- [functional regression] Tool coverage: 100 → unverified
- [functional regression] Schema quality: 100 → unverified

### 2026-07-27 (score 50)

First indexed and scored.

## MCP tools (6)

### `setup` (~195 tokens)

Show the LemonCake MCP first-run setup guide. No authentication required.
Call this tool FIRST to learn what is missing and how to obtain a permit.

If LEMON_CAKE_PERMIT is not set, the server is in DEMO MODE: list_services returns
8 free demo services (search / echo / fx / translate / weather / geocode / time / dictionary)
powered by real upstreams (Wikipedia, httpbin, Open-Meteo, Nominatim, etc.). call_service
and check_balance respond with mock data so you can verify integration before signing.

Returns the current credential status (permit presence), demo-mode flag, and
step-by-step instructions for getting a permit at /start/v2, including a sample MCP
client config snippet ready to paste.

Returns: { version, apiUrl, mode, credentials, availableTools, setupSteps, permitUrl, docs }
Errors: none — this tool always succeeds.

### `list_services` (~272 tokens)

List approved API services available on the LemonCake marketplace. No authentication required.

Use this BEFORE call_service to discover serviceId values and per-call USDC pricing.

When LEMON_CAKE_PERMIT is missing, 8 demo services are prepended:
  demo_search     → Wikipedia opensearch
  demo_echo       → httpbin.org/anything
  demo_fx         → live FX rates (open.er-api)
  demo_translate  → 80+ languages (MyMemory)
  demo_weather    → current weather any lat/lon (Open-Meteo)
  demo_geocode    → place name → lat/lon (OpenStreetMap Nominatim)
  demo_time       → IANA timezone time + DST (worldtimeapi)
  demo_dictionary → English definitions / synonyms (dictionaryapi.dev)
All real upstreams, no auth, free. Live users (permit set) see real
marketplace entries; demo_* IDs remain callable directly.

Each item: { id, name, provider, type ('API' | 'MCP'), pricePerCall, [usage], [mode] }.
Errors: HTTP-level errors are returned as `Error: API <status>: <body>`.

Input parameters:

- `limit` (integer): Maximum number of services to return (default 50, max 100).

### `call_service` (~693 tokens)

Invoke an upstream API service through LemonCake's pay-per-call proxy.
Each successful call automatically debits USDC from your wallet via the permit you signed.
LemonCake never holds your USDC — the transfer is direct wallet → provider on Base.

PRECONDITIONS:
  • LEMON_CAKE_PERMIT env var must be set for real services. Get one in ~30 seconds at
    https://lemoncake.xyz/start/v2 (sign in with Google, sign 1 EIP-712 permit, copy the blob).
    If missing, the tool returns a structured PERMIT_MISSING error with how-to-fix steps.
  • DEMO MODE: any serviceId starting with `demo_` works WITHOUT a permit and hits real
    free upstreams (Wikipedia / httpbin / Open-Meteo / Nominatim / MyMemory / dictionaryapi /
    worldtimeapi / open.er-api). 8 demos cover search / echo / fx / translate / weather /
    geocode / time / dictionary — useful for Glama Inspector or new-user trial. They are
    marked with `mode: "demo"` and incur no charge.
  • serviceId must come from list_services.

BEHAVIOR:
  • Returns the upstream response body verbatim (JSON or text), plus the X-Charge-Id
    and X-Amount-Usdc headers reported by the proxy.
  • HTTP 402 Payment Required is returned as a normal result (NOT thrown) so the
    agent can autonomously stop spending when the daily $25 permit cap is exhausted.
  • Pass the same idempotencyKey to retry safely without double-charging.
  • This tool spends real money and contacts an external service — it is
    non-idempotent by default and has external side effects.

x402-COMPATIBLE INTERFACE:
  • Successful calls include an `x402Receipt` field with { scheme, chain, asset, amount,
    recipient, paymentIntentId, settledAt }. Same shape as on-chain x402 receipts so the
    agent's payment-handling logic is portable.
  • If upstream returns an x402 challenge (WWW-Authenticate: x402, X-402-* headers, or
    body.x402), it's parsed into `x402Challenge` for the agent to reason about.
  • If upstream returns 202 + Retry-After + X-Payment-Status: p…

Input parameters:

- `body` (object): JSON request body (only used for POST/PUT/PATCH).
- `idempotencyKey` (string): Optional idempotency key (UUID recommended). Identical keys within the proxy's retention window return the cached result without re-charging.
- `method` (string): HTTP method to use against the service. Defaults to GET.
- `path` (string): Sub-path on the service (e.g. "/search", "/v1/completions"). Defaults to "/".
- `serviceId` (string, required): ID of the service to call (obtain from list_services).

### `check_balance` (~137 tokens)

Check the current on-chain USDC balance of the wallet that owns the configured permit.

PRECONDITIONS:
  • DEMO MODE (no LEMON_CAKE_PERMIT): returns a canned $1.00 demo balance so trial
    users see something useful before signing.
  • LIVE: queries Base USDC.balanceOf(owner) directly + reports remaining daily permit
    cap. LemonCake's backend doesn't store the balance — it's read from the chain.

Use BEFORE call_service to confirm sufficient funds and remaining daily cap.

Returns: { balanceUsdc, dailyCap, remainingToday, ownerAddress, [mode], [note] }

### `check_tax` (~235 tokens)

Run a Japanese tax compliance check on a single transaction. No authentication required.

Performs three checks in one call:
  1\. Validates the qualified-invoice registration number (T-number) against the NTA registry.
  2\. Determines whether source-withholding (源泉徴収) applies based on the service description.
  3\. If withholding applies, computes the withholding amount and net payable.

Intended for Japanese corporations that pay AI / API services and need to file
withholding correctly under the qualified-invoice (インボイス制度) regime.

Returns: { invoice: { valid, name, ... }, withholding: { required, rate, amount, net } }
Errors: invalid registrationNumber returns invoice.valid = false (not an exception).

Input parameters:

- `grossAmountJpy` (number, required): Gross transaction amount in JPY, tax inclusive.
- `registrationNumber` (string, required): Qualified-invoice registration number issued by the Japanese NTA (e.g. "T1234567890123").
- `serviceDescription` (string, required): Plain-text description of what was purchased. Used to classify whether source-withholding applies.

### `get_service_stats` (~78 tokens)

Return public usage statistics for every approved service on the marketplace. No authentication required.

Use this AFTER list_services and BEFORE call_service to pick a service based on
real-world traction (call counts, USDC revenue, last-used timestamp).

Returns: an array of { serviceId, callCount, totalRevenueUsdc, lastCalledAt }.

## Diagnostics

Captured diagnostic sections: Provenance, Dependencies. The full working is on the page: https://verifymcp.io/servers/evidai-agent-payment/agent-payment-mcp#diagnostics

## Score history

- 2026-08-03: 68
- 2026-08-02: 64
- 2026-08-01: 24
- 2026-07-31: 6
- 2026-07-29: 50
- 2026-07-28: 50
- 2026-07-27: 50

## Links

- npm package: https://www.npmjs.com/package/agent-payment-mcp
- Socket report: https://socket.dev/npm/package/agent-payment-mcp
- Repository: https://github.com/evidai/agent-payment-mcp
- Changelog RSS feed: https://verifymcp.io/servers/evidai-agent-payment/agent-payment-mcp/changelog.xml
- Changelog JSON feed: https://verifymcp.io/servers/evidai-agent-payment/agent-payment-mcp/changelog.json
- HTML version of this page: https://verifymcp.io/servers/evidai-agent-payment/agent-payment-mcp