DERATE — truck fault codes

by derate.app · remote · no sign-in to list tools · v2.0.0 · published by app.derate

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

Changes · 4

Compare Registry entry

15 tools: 4 change things and 11 only read.

Scanned Oct 21, 2026

Deletes or cancels0Claude Code: deny
Can't be undone0Claude Code: ask
Changes things4Claude Code: ask: see these tools
Only reads11Claude Code: allow: see these tools

3 checks matched something in the tool definitions. No finding is not a safety guarantee. How the checks work.

claude mcp add --transport http derate https://derate.app/mcp

Findings

Matches of fixed checks, with the text they matched.

3 warn

Warnes_seguro_manejar
The server marks "es_seguro_manejar" read-only (readOnlyHint: true), and its own name, description or input give the class "write".
Matched text
annotations: {"readOnlyHint":true,"idempotentHint":true,"openWorldHint":false}; The input takes a statement or command to run (input.code), which can change anything it can reach.
What this check looks for
Warnget_truck_fault_code
The server marks "get_truck_fault_code" read-only (readOnlyHint: true), and its own name, description or input give the class "write".
Matched text
annotations: {"readOnlyHint":true,"idempotentHint":true,"openWorldHint":false}; The name "get_truck_fault_code" says "get": a word for reading.
What this check looks for
Warninterpret_derate
The server marks "interpret_derate" read-only (readOnlyHint: true), and its own name, description or input give the class "write".
Matched text
annotations: {"readOnlyHint":true,"idempotentHint":true,"openWorldHint":false}; The description's first verb is "explain": a word for reading.
What this check looks for

Tools

Open a tool for its reasons and full description. Descriptions are the publisher's own words, shown as they are.

15 tools

Changes things 4Creates or changes something that can be changed back.Claude Code: ask

es_seguro_manejarSafe-to-drive verdict (stop / service_soon / info) for a truck fault code, from DERATE's library only.1 finding
Why it is in this group
- The input takes a statement or command to run (input.code), which can change anything it can reach.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
Findings
- Warn
  The server marks "es_seguro_manejar" read-only (readOnlyHint: true), and its own name, description or input give the class "write".
  Matched text
  annotations: {"readOnlyHint":true,"idempotentHint":true,"openWorldHint":false}; The input takes a statement or command to run (input.code), which can change anything it can reach.
  What this check looks for
Description, as the server wrote it
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.
Annotations the server declares
- readOnlyHint: true
- idempotentHint: true
- openWorldHint: false
get_truck_fault_codeLook 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.1 finding
Why it is in this group
- The name "get_truck_fault_code" says "get": a word for reading.
- The input takes a statement or command to run (input.code), which can change anything it can reach.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
Findings
- Warn
  The server marks "get_truck_fault_code" read-only (readOnlyHint: true), and its own name, description or input give the class "write".
  Matched text
  annotations: {"readOnlyHint":true,"idempotentHint":true,"openWorldHint":false}; The name "get_truck_fault_code" says "get": a word for reading.
  What this check looks for
Description, as the server wrote it
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.
Annotations the server declares
- readOnlyHint: true
- idempotentHint: true
- openWorldHint: false
interpret_derateExplain a diesel truck engine derate or power-loss symptom described in plain language (for example 'DEF light on and truck limited to 55 mph').1 finding
Why it is in this group
- The description's first verb is "explain": a word for reading.
- The input takes a statement or command to run (input.code), which can change anything it can reach.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
Findings
- Warn
  The server marks "interpret_derate" read-only (readOnlyHint: true), and its own name, description or input give the class "write".
  Matched text
  annotations: {"readOnlyHint":true,"idempotentHint":true,"openWorldHint":false}; The description's first verb is "explain": a word for reading.
  What this check looks for
Description, as the server wrote it
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.
Annotations the server declares
- readOnlyHint: true
- idempotentHint: true
- openWorldHint: false
retiros_de_camionHow to check heavy-truck safety recalls (NHTSA-based), with per-make source links for Freightliner, Volvo, Kenworth, Peterbilt, International, Mack and Western Star.No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
Description, as the server wrote it
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.
Annotations the server declares
- readOnlyHint: true
- idempotentHint: true
- openWorldHint: false

Only reads 11Looks things up and changes nothing.Claude Code: allow

buscar_codigoSearch DERATE's 56-code heavy-truck library by SPN/FMI, P-code or free text.No findings
Why it is in this group
- The description's first verb is "search": a word for reading.
Description, as the server wrote it
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.
Annotations the server declares
- readOnlyHint: true
- idempotentHint: true
- openWorldHint: false
explain_fault_codeExplain 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.No findings
Why it is in this group
- The name "explain_fault_code" says "explain": a word for reading.
Description, as the server wrote it
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.
Annotations the server declares
- readOnlyHint: true
- idempotentHint: true
- openWorldHint: false
get_data_notesDERATE dataset notes: code count, sources, known gaps, license (CC BY 4.0), how to cite and download URLs.No findings
Why it is in this group
- The name "get_data_notes" says "get": a word for reading.
Description, as the server wrote it
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.
Annotations the server declares
- readOnlyHint: true
- idempotentHint: true
- openWorldHint: false
get_diagnosisReturn the full DERATE demo diagnosis for a truck: verdict (STOP/CAUTION/CLEAR), derate countdown, every fault code and the work order summary.No findings
Why it is in this group
- The name "get_diagnosis" says "get": a word for reading.
Description, as the server wrote it
Return the full DERATE demo diagnosis for a truck: verdict (STOP/CAUTION/CLEAR), derate countdown, every fault code and the work order summary.
Annotations the server declares
- readOnlyHint: true
- idempotentHint: true
- openWorldHint: false
get_download_linksReturn the official App Store and Google Play links for the DERATE native app (iOS and Android).No findings
Why it is in this group
- The name "get_download_links" says "get": a word for reading.
Description, as the server wrote it
Return the official App Store and Google Play links for the DERATE native app (iOS and Android). DERATE runs only as a mobile app.
Annotations the server declares
- readOnlyHint: true
- idempotentHint: true
- openWorldHint: false
get_guideFull text (markdown) of one DERATE guide or news article by slug, with sources and the derate.app URL to cite.No findings
Why it is in this group
- The name "get_guide" says "get": a word for reading.
Description, as the server wrote it
Full text (markdown) of one DERATE guide or news article by slug, with sources and the derate.app URL to cite. / Texto completo de una guía o noticia.
Annotations the server declares
- readOnlyHint: true
- idempotentHint: true
- openWorldHint: false
get_pricingList DERATE's plans and prices in USD.No findings
Why it is in this group
- The name "get_pricing" says "get": a word for reading.
Description, as the server wrote it
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.
Annotations the server declares
- readOnlyHint: true
- idempotentHint: true
- openWorldHint: false
list_fault_codesList the fault codes (SPN/FMI) in the current DERATE diagnosis with severity, system, fault type and whether they are a root cause.No findings
Why it is in this group
- The name "list_fault_codes" says "list": a word for reading.
Description, as the server wrote it
List the fault codes (SPN/FMI) in the current DERATE diagnosis with severity, system, fault type and whether they are a root cause.
Annotations the server declares
- readOnlyHint: true
- idempotentHint: true
- openWorldHint: false
list_supported_engine_familiesList 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.No findings
Why it is in this group
- The name "list_supported_engine_families" says "list": a word for reading.
Description, as the server wrote it
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.
Annotations the server declares
- readOnlyHint: true
- idempotentHint: true
- openWorldHint: false
search_fault_code_libraryFull-text search over DERATE's public diesel truck fault-code library by code, system, dashboard light or symptom words.No findings
Why it is in this group
- The name "search_fault_code_library" says "search": a word for reading.
Description, as the server wrote it
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.
Annotations the server declares
- readOnlyHint: true
- idempotentHint: true
- openWorldHint: false
search_guidesSearch DERATE's truck-driver guides and trucking news (derate, DEF, emissions, recalls, enforcement, market).No findings
Why it is in this group
- The name "search_guides" says "search": a word for reading.
Description, as the server wrote it
Search DERATE's truck-driver guides and trucking news (derate, DEF, emissions, recalls, enforcement, market). Returns title, quick answer and derate.app URL. / Busca en las guías y noticias de DERATE.
Annotations the server declares
- readOnlyHint: true
- idempotentHint: true
- openWorldHint: false

This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.

Install

Pinned to version 2.0.0. Values in angle brackets are yours to fill in.

claude mcp add --transport http derate https://derate.app/mcp

Run in a terminal.

Claude Code permissions

Allow the reads, ask before a change, deny the deletes. Paste into .claude/settings.json.

.claude/settings.json

{
  "permissions": {
    "allow": [
      "mcp__derate__buscar_codigo",
      "mcp__derate__get_data_notes",
      "mcp__derate__search_guides",
      "mcp__derate__get_guide",
      "mcp__derate__search_fault_code_library",
      "mcp__derate__list_supported_engine_families",
      "mcp__derate__get_pricing",
      "mcp__derate__get_download_links",
      "mcp__derate__get_diagnosis",
      "mcp__derate__list_fault_codes",
      "mcp__derate__explain_fault_code"
    ],
    "ask": [
      "mcp__derate__es_seguro_manejar",
      "mcp__derate__retiros_de_camion",
      "mcp__derate__get_truck_fault_code",
      "mcp__derate__interpret_derate"
    ],
    "deny": []
  }
}

Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. It assumes the server is installed as derate. Review it before you use it.

Keep track

Get told when this server's tools change: a new tool, a new description, a new class.

https://anlyon.dev/servers/app.derate/derate/changes.xml

An Atom feed. Works in any feed reader or Slack's RSS app.

Anlyon alternative

4 of these tools change something. Run those as governed actions.

Declare what an action changes, and Anlyon puts it under a shared limit, binds every approval to the exact request, and grades the outcome. It works on any HTTPS API you can describe as an action.

Anlyon does not run, proxy or govern this MCP server. A tool your own code calls directly is not routed through Anlyon and is not governed by it.

Import an OpenAPI spec →

Compare with other servers for the same product.

Source: MCP Registry. Synced Oct 21, 2026, 17:44 UTC.

For agents: Markdown · JSON · report this listing