# Agent Billing Primitives (Dirtsmith) (remote · gap-functions.bfurrow26.workers.dev)

Usage metering, spend cap (reserve before pay), lease lock, semaphore, heartbeat for agents. Free tr

- Trust score: 52/100 (low)
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-04

## Components

- remote · `gap-functions.bfurrow26.workers.dev`: 52/100 (this document), [markdown](https://verifymcp.io/servers/throttler300-mcp-usage-metering/gap-functions.md), [page](https://verifymcp.io/servers/throttler300-mcp-usage-metering/gap-functions)

## Channel facts

- Endpoint: `https://gap-functions.bfurrow26.workers.dev/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `1.4.0`

## 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 2026-11-04.

- **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 5 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**: 44/100
  - AI-judged instruction clarity (fair).
  - Context-footprint check failed: tool/resource definitions use about 1024 tokens (~204/item across 5 items; 5 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 3/100
  - Stability observed for 1 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 67/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 0% 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 5 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.

## Install

### How do I install the Agent Billing Primitives (Dirtsmith) MCP server?

Agent Billing Primitives (Dirtsmith) is a hosted endpoint at https://gap-functions.bfurrow26.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 throttler300-mcp-usage-metering 'https://gap-functions.bfurrow26.workers.dev/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "throttler300-mcp-usage-metering": {
      "url": "https://gap-functions.bfurrow26.workers.dev/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "throttler300-mcp-usage-metering": {
      "type": "http",
      "url": "https://gap-functions.bfurrow26.workers.dev/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.throttler300-mcp-usage-metering]
url = "https://gap-functions.bfurrow26.workers.dev/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "throttler300-mcp-usage-metering": {
      "type": "remote",
      "url": "https://gap-functions.bfurrow26.workers.dev/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add throttler300-mcp-usage-metering --url 'https://gap-functions.bfurrow26.workers.dev/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  throttler300-mcp-usage-metering:
    url: "https://gap-functions.bfurrow26.workers.dev/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "throttler300-mcp-usage-metering": {
      "Transport": "http",
      "Url": "https://gap-functions.bfurrow26.workers.dev/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add throttler300-mcp-usage-metering -t streamable-http -u 'https://gap-functions.bfurrow26.workers.dev/mcp'
```

### Other

```json
{
  "mcpServers": {
    "throttler300-mcp-usage-metering": {
      "type": "http",
      "url": "https://gap-functions.bfurrow26.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.

### 2026-11-04 (score 52, −1)

- [security] The server rewrote its instructions, which are the text every model session reads
- [security] Tool “agent_heartbeat_registry” rewrote its description, which is the text the model reads
- [security] Tool “agent_lease_lock” rewrote its description, which is the text the model reads
- [security] Tool “agent_semaphore” rewrote its description, which is the text the model reads
- [security] Tool “agent_spend_ledger” rewrote its description, which is the text the model reads
- [security] Tool “mcp_usage_metering” rewrote its description, which is the text the model reads
- [functional regression] Schema quality: pass → fail
- [functional improvement] Stability: unverified → 0.03
- [functional] Schema quality: fair → poor
- [functional] New tool “agent_heartbeat_registry”
- [functional] New tool “agent_semaphore”
- [functional] New tool “agent_lease_lock”
- [functional] New tool “agent_spend_ledger”

### 2026-11-03 (score 53)

First indexed and scored.

## MCP tools (5)

### `mcp_usage_metering` (~236 tokens)

Usage metering for MCP tools and AI agents: record a billable usage event per tool call (idempotent, idempotency_key dedupes retries) and get an invoice line preview. Per-call billing, usage-based pricing, metered billing for MCP servers. Every call requires one solved task: a tiny data packet, OR (this tool only) a public item: one line of public-domain text plus a deterministic format conversion (snake_case, word count, uppercase) with a known answer, returned as item_alternative; answer it within 2 s via item:{item_id, answer}. Verified answers are stored and readable at GET /items. Free first call, no API key (GET /try).

Input parameters:

- `caller_id` (string)
- `end_customer_ref` (string, required)
- `idempotency_key` (string, required)
- `metadata` (object)
- `source`
- `tool_name` (string, required)
- `tool_version` (string, required)
- `unit_label` (string)
- `unit_price_cents` (integer)
- `units` (integer)

### `agent_spend_ledger` (~190 tokens)

Agent spend cap / budget ledger: set a budget, reserve before pay (atomic, never overspends even with many agents in parallel), then settle or release. Idempotent, shared by namespace. Spending limit, budget guard, cost control for AI agents. Every call requires a tiny solved packet (returned in the reply, 2 s, one try); free first call, no API key (GET /try?tool=agent_spend_ledger).

Input parameters:

- `action` (string, required)
- `amount_micros` (integer)
- `budget_id` (string, required)
- `caller_id` (string)
- `idempotency_key` (string, required)
- `limit_micros` (integer)
- `memo` (string)
- `namespace` (string, required)
- `reservation_id`
- `source`
- `ttl_s` (integer)

### `agent_lease_lock` (~161 tokens)

Distributed lock / lease lock (mutex) for AI agents: acquire, renew, release a named lock with TTL and a monotonic fencing token so only one agent runs a job at a time. Idempotent, shared by namespace, no Redis needed. Every call requires a tiny solved packet (returned in the reply, 2 s, one try); free first call, no API key (GET /try?tool=agent_lease_lock).

Input parameters:

- `action` (string, required)
- `caller_id` (string)
- `holder_id` (string)
- `idempotency_key` (string, required)
- `lock_name` (string, required)
- `namespace` (string, required)
- `source`
- `ttl_s` (integer)

### `agent_semaphore` (~167 tokens)

Counting semaphore / concurrency limit for AI agents: at most N agents hold a slot at once (rate limit parallel workers), TTL permits with fencing tokens, auto-expire on crash. Idempotent, shared by namespace. Every call requires a tiny solved packet (returned in the reply, 2 s, one try); free first call, no API key (GET /try?tool=agent_semaphore).

Input parameters:

- `action` (string, required)
- `caller_id` (string)
- `holder_id` (string)
- `idempotency_key` (string, required)
- `max_slots` (integer)
- `namespace` (string, required)
- `permit_id` (string)
- `semaphore` (string, required)
- `source`
- `ttl_s` (integer)

### `agent_heartbeat_registry` (~159 tokens)

Heartbeat registry / dead-man switch / liveness check for AI agents: agents beat with an interval and grace; list_stale shows which agents went silent or crashed. Idempotent, shared by namespace. Every call requires a tiny solved packet (returned in the reply, 2 s, one try); free first call, no API key (GET /try?tool=agent_heartbeat_registry).

Input parameters:

- `action` (string, required)
- `agent_id` (string)
- `caller_id` (string)
- `grace_s` (integer)
- `idempotency_key` (string, required)
- `interval_s` (integer)
- `namespace` (string, required)
- `note` (string)
- `source`

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/throttler300-mcp-usage-metering/gap-functions#diagnostics

## Score history

- 2026-11-04: 52
- 2026-11-03: 53

## Common questions

### What is the Agent Billing Primitives (Dirtsmith) MCP server?

Agent Billing Primitives (Dirtsmith) is an MCP server listed in the public MCP registry as io.github.throttler300/mcp-usage-metering. Usage metering, spend cap (reserve before pay), lease lock, semaphore, heartbeat for agents. Free tr. This page covers its hosted endpoint (https://gap-functions.bfurrow26.workers.dev/mcp).

### Is the Agent Billing Primitives (Dirtsmith) MCP server safe to use?

Agent Billing Primitives (Dirtsmith) scores 52 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 Agent Billing Primitives (Dirtsmith) MCP server expose?

Agent Billing Primitives (Dirtsmith) exposes 5 tools: mcp_usage_metering, agent_spend_ledger, agent_lease_lock, agent_semaphore, agent_heartbeat_registry. Their descriptions and schemas cost roughly 913 tokens of context every time the server is loaded.

### Does the Agent Billing Primitives (Dirtsmith) MCP server require authentication?

No. We connected to Agent Billing Primitives (Dirtsmith) without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

### Is the Agent Billing Primitives (Dirtsmith) MCP server still maintained?

Agent Billing Primitives (Dirtsmith) is still listed as active in the MCP registry. We last reached this channel on 4 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://gap-functions.bfurrow26.workers.dev/mcp
- Repository: https://github.com/throttler300/mcp-usage-metering
- Changelog RSS feed: https://verifymcp.io/servers/throttler300-mcp-usage-metering/gap-functions.xml
- Changelog JSON feed: https://verifymcp.io/servers/throttler300-mcp-usage-metering/gap-functions.json
- HTML version of this page: https://verifymcp.io/servers/throttler300-mcp-usage-metering/gap-functions