# DERATE — truck fault codes

> Heavy-duty truck SPN/FMI and OBD fault codes: meaning, safe-to-drive verdict, parts and recalls.

- name: app.derate/derate
- version: 2.0.0
- connection class: R0 (autonomous)
- trust: 83/100 flags: no-repository
- quality: 85/100 (good)
- owner: not claimed
- descriptor: https://api.protogrid.dev/v1/servers/app.derate%2Fderate
- tools: https://api.protogrid.dev/v1/servers/app.derate%2Fderate/tools

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

## Connection (mcpServers)

```json
{
  "mcpServers": {
    "derate": {
      "type": "http",
      "url": "https://derate.app/mcp"
    }
  }
}
```


## Trust

- hygiene: 80
- liveness: 100
- freshness: 100
- provenance: 55
- drivers: +dns-namespace +website +reachable +uptime-100% +updated-10d-ago -no-repository
- Derived from observable signals (official registry feed and our own credential-free probes); no code audit performed.

## Quality 85/100 (good)

### protocol: 75 (weight 25)

- warn `protocol.modern`: newest supported version is 2025-06-18; 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: 86 (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`: 13 of 13 tools declare readOnlyHint or destructiveHint
- fail `tools.directory_hints`: no tool declares all four of readOnlyHint, destructiveHint, idempotentHint and openWorldHint; missing: buscar_codigo (destructiveHint); list_supported_engine_families (destructiveHint); get_data_notes (destructiveHint); …
- pass `tools.token_cost`: about 1,909 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: 13, about 1,909 tokens to load them all
- tool set hash: 64616dd6552393880f95d9f12810175c
- badge: [![protogrid quality](https://protogrid.dev/badge/app.derate/derate.svg)](https://protogrid.dev/servers/app.derate/derate)
- 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://derate.app/mcp (streamable-http, auth none, reachable true, uptime30d 1)

## Packages

_none_

## Tools (13)

- `buscar_codigo`: Search DERATE's 56-code heavy-truck library by SPN/FMI, P-code or free text. Returns severity, derates yes/no, meaning, part and estimated part-price range, and the page URL. / Busca en la biblioteca de códigos de DERATE.
- `es_seguro_manejar`: Safe-to-drive verdict (stop / service_soon / info) for a truck fault code, from DERATE's library only. Unknown codes return 'unknown'. / Veredicto de si es seguro seguir manejando.
- `explain_fault_code`: Explain a truck fault code or symptom in DERATE terms: plain-language meaning, severity, probable causes, recommended tests with expected values, repair steps and cost estimate.
- `get_data_notes`: DERATE dataset notes: code count, sources, known gaps, license (CC BY 4.0), how to cite and download URLs. / Notas de calidad, licencia y cómo citar.
- `get_diagnosis`: Return the full DERATE demo diagnosis for a truck: verdict (STOP/CAUTION/CLEAR), derate countdown, every fault code and the work order summary.
- `get_download_links`: Return the official App Store and Google Play links for the DERATE native app (iOS and Android). DERATE runs only as a mobile app.
- `get_pricing`: List DERATE's plans and prices in USD. The app is a free download; plans are purchased inside the iOS/Android app (App Store / Google Play). Monthly Driver and Shop plans include a 7-day free trial for new subscribers.
- `get_truck_fault_code`: Look up a diesel truck fault code (J1939 SPN/FMI such as 'SPN 3251 FMI 0', or an OBD-II code such as 'P2002') in DERATE's public fault-code library. Returns what the code means, its severity, whether it is safe to keep driving, probable causes, the recommended tests, and the canonical URL of the public page for that code. Works without any account.
- `interpret_derate`: Explain a diesel truck engine derate or power-loss symptom described in plain language (for example 'DEF light on and truck limited to 55 mph'). Returns the most likely cause, how urgent it is, the immediate action to take, and matching public fault-code pages. This is the free public interpretation; the full guided diagnosis with tests and a work order runs in the DERATE app.
- `list_fault_codes`: List the fault codes (SPN/FMI) in the current DERATE diagnosis with severity, system, fault type and whether they are a root cause.
- `list_supported_engine_families`: List the diesel truck engine families and code protocols DERATE interprets (J1939 SPN/FMI and OBD-II), so an agent knows whether a given truck is covered before looking up a code.
- `retiros_de_camion`: How to check heavy-truck safety recalls (NHTSA-based), with per-make source links for Freightliner, Volvo, Kenworth, Peterbilt, International, Mack and Western Star. / Cómo revisar retiros de seguridad.
- `search_fault_code_library`: Full-text search over DERATE's public diesel truck fault-code library by code, system, dashboard light or symptom words. Returns a list of matching entries with code, title, severity, system and the canonical public URL.