AskMarcel HVAC Technical Knowledge

Name: AskMarcel HVAC Technical Knowledge
Author: askmarcel

by askmarcelversion 1.3.1-beta.1i★ –iRuns in the cloud

Registry nameio.github.askmarcel/mcphvac

Install

Overview

Description from the maker (original English)

15 HVAC MCP tools: lookups, SKU provenance, guided PAC, Beta Harness sessions. 126 brands.

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

User voiceiNo reviews yetReviews open together with accounts in a later step
Our basic checksi1 of 1 passedChecked from public information; code not scanned yet
UsageiNot measured yet★ –

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

Connection: Runs in the cloud
Transport: Streamable HTTP
Category: Search & AI memory

Install

Pick the AI app you use, then copy the settings.

Before you install

Basic checks: 1 of 1 passed
Runs on the maker’s server: what you ask it goes through their server.
The registry lists no key to fill in.

You need

Runs in the cloudNothing to install; it connects over the internet

Which app do you use?

ClaudeClaude CodeCursorVS CodeChatGPT

Pick your app above. We remember it, so next time the button says “Install in …”.

Works in Claude on the web, desktop and mobile:

Open Settings → Connectors
Press Add custom connector
Paste the address below and press Add
If it asks you to sign in, sign in with the maker

https://mcp.askmarcel.app

Run this in your terminal

claude mcp add --transport http mcphvac https://mcp.askmarcel.app

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "mcphvac": {
      "url": "https://mcp.askmarcel.app"
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "mcphvac": {
      "type": "http",
      "url": "https://mcp.askmarcel.app"
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

ChatGPT connects only to servers on the internet:

Open ChatGPT on the web → Settings → Connectors (Apps)
Press Create or Add (some plans need Developer mode under Advanced first)
Paste the address below, give it a name and save
If it asks you to sign in, sign in with the maker

https://mcp.askmarcel.app

Menu names can differ slightly by plan and over time.

Your choice stays on this device in a cookie; no account needed.

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

We have not read this server’s tool list yet; we check endpoints in rotation.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 6, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account askmarcel, which owns the repo
… Not checked yet
Still maintained
We have not read this repo from GitHub yet
… Not checked yet
Has a licence
We have not read this repo from GitHub yet
… Not checked yet
Endpoint responds
Not checked yet; we check endpoints in rotation
… Not checked yet
Sign-in with OAuth
Not checked yet; we check endpoints in rotation
… Not checked yet
No hidden instructions in tool descriptions
Not checked yet; we read the tool list when we check the endpoint

Compared with others in Search & AI memoryi

More stars than 0% of the other 7243 servers in this category
Published to the registry more recently than 34% of the other 7243 servers in this category
Basic checks equal to or better than 100% of the other 7243 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is AskMarcel HVAC Technical Knowledge safe?

It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

The registry does not list a required key, though some servers ask you to sign in on first use.

Does it run on my computer or in the cloud?

It runs in the maker’s cloud. Connect over the internet with nothing to install, but what you send passes through the maker’s servers.

Is it still maintained?

The GitHub repo last changed –, and the latest version (1.3.1-beta.1) reached the registry 2 months ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. It connects by URL, so apps that accept remote MCP servers work too, such as ChatGPT in developer mode.

What can I use instead?

In the same category: Context7, Codebase Memory, Exa

Alternatives

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Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

Context7

by upstash

Feeds AI the latest docs for libraries and frameworks before it answers, so code it writes does not use outdated, removed functions.

Computer or cloud★ 64,224MITUpdated 3 days ago

Install

Codebase Memory

by DeusData

Codebase knowledge graph for AI agents — 162 languages, sub-ms queries, 99% fewer tokens.

Runs on your computer★ 48,148MITUpdated 20 days ago

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Exa

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Connect AI agents to Exa for web search, content fetching, and multi-step research.

Runs in the cloud★ 5,213MITUpdated 44 days ago

Install

README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

AskMarcel — HVAC Technical Knowledge MCP Server

Manufacturer-sourced HVAC technical documentation for AI agents: search, diagnostics, error codes, procedures and product sheets across 126 brands and 905 models .

AskMarcel is a remote, hosted MCP server (Streamable HTTP). There is nothing to install or self-host — point your MCP client at the endpoint and authenticate. The server connects AI agents to real manufacturer documentation so answers cite the exact manual and page number instead of hallucinating.

Endpoint: https://mcp.askmarcel.app
Registry name: io.github.askmarcel/mcphvac
Manifest: 1.3.1-beta.1 — 15 tools live in production
Docs & API key: https://app.askmarcel.app/developers
Reference: https://app.askmarcel.app/developers/reference
Marcel Inside (B2B API / MCP): https://askmarcel.app/fr/connecteurs
Free Developer tier: 250 API calls / month

Marcel Inside — branch it behind your bot

Use AskMarcel as Marcel Inside: plug manufacturer-sourced HVAC knowledge behind your existing chatbot, voicebot, or agent — without rebuilding your stack. Compatible with ManyChat, ElevenLabs, Voiceflow, Intercom, Claude, ChatGPT, Gemini, and custom MCP clients.

Sales & pilot: https://askmarcel.app/fr/connecteurs (490€ pilot, Business 149€/mois HT)
Developer sandbox: free tier — 250 calls/month at https://app.askmarcel.app/developers

Why AskMarcel

General-purpose LLMs guess at HVAC specifics — refrigerant charge, error-code meanings, wiring, fault trees. AskMarcel grounds every response in indexed manufacturer PDFs and returns the source page, so a field technician or an agent can trust and verify the answer. See HVAC-Bench for measured accuracy vs. raw LLM output.

126 brands · 905 models · 400,000+ error codes indexed
Deterministic error-code lookup (not a guess)
Strict SKU provenance (resolve_model, get_model_coverage, diagnose_v2) — no family substitution
Sourced one-shot lookups (diagnose) and multi-turn guided troubleshooting for air-to-water heat pumps (diagnose_guided)
LIVE Beta Harness sessions — stateful diagnostic loop with manufacturer DB lookup at session start (start_diagnostic … get_diagnostic_summary)
FR / EN, focused on the European HVAC/RACH market

Harness session vs `diagnose_guided`

Surface	Use when	Quota
Harness session (`start_diagnostic` …)	Multi-turn field diagnostic on PAC Air/Eau or PAC Air/Air with hypotheses, discriminating `next_action`, technician journal	Once at session creation
`diagnose_guided`	Legacy guided loop for PAC Air/Eau only — server-sealed state via `continuation`	Per turn
`diagnose_v2`	One-shot strict SKU lookup	Per successful call
`diagnose`	One-shot lookup without SKU gate	Per successful call

Harness Beta is live in production (DIAGNOSTIC_SESSIONS_PUBLIC=true). At start_diagnostic, the server looks up error codes in technical_error_codes (manufacturer DB) and journals the result — not only pack fallback maps. Active packs: pac_air_eau and pac_air_air at `0.0.1` (mutable during Beta).

Tools

The server exposes 15 tools (10 GA + 5 Beta Harness session). Full reference in docs/tools.md.

GA (10)

Tool	What it does
`search_technical_docs`	Semantic search over technical documentation (≤10 excerpts). Filter by `brand`, `model`, `error_code`.
`get_procedure`	Retrieve a full procedure by `chunk_id`.
`get_error_code`	Deterministic lookup by `brand` + `error_code` (optional `model`).
`get_product_sheet`	Product sheet: specs, composition, frequent error codes, by `brand` + `model`.
`get_pdf_page_snapshot`	Signed, 5-minute URL to a specific PDF page (`document_id` + `page`).
`diagnose`	One-shot sourced lookup from a symptom or error code (excerpt + steps + citation).
`diagnose_v2`	Same lookup with strict SKU provenance. Abstains (`diagnostic: null`) if no approved exact-model manual exists.
`resolve_model`	Resolve `brand` + `model` to a canonical SKU. Exact or alias only — never a series LIKE.
`get_model_coverage`	Documentary flags for a resolved SKU: `exact_manual`, `error_code_covered`, `market_verified`.
`diagnose_guided`	Multi-turn guided troubleshooting for air-to-water heat pumps (legacy; quota per turn).

Beta — Harness session (5)

Tool	What it does
`start_diagnostic`	Open a stateful Harness session. Manufacturer error-code lookup at start. Quota on creation.
`get_diagnostic`	Read current session projection (`hypotheses`, `next_action`, fault code).
`respond_to_diagnostic`	Append typed observation, measurement, or technician assessment.
`close_diagnostic`	Close session with optional reason (verification not required).
`get_diagnostic_summary`	Deterministic exportable summary from the session journal.

Stability: beta · release_channel: beta on responses · qualified HVAC professional required.

Quick start

1. Get an API key

Create a free key at https://app.askmarcel.app/developers (250 calls/month on the Developer tier). The server also supports OAuth 2.0 (PKCE + Dynamic Client Registration) for clients that discover auth automatically.

2. Connect your MCP client

Ready-to-use configs live in examples/. The general form for any Streamable HTTP MCP client:

"mcpServers": { "askmarcel": { "type": "streamable-http", "url": "https://mcp.askmarcel.app", "headers": { "Authorization": "Bearer YOUR_API_KEY" } } } }

Claude Desktop / Cursor / VS Code: see the matching file in examples/. Replace YOUR_API_KEY with your key.

3. Ask a question

Once connected, prompt naturally, e.g.:

"Daikin Altherma showing error U4 — what does it mean and how do I clear it?"

The agent calls resolve_model / diagnose_v2 (or get_error_code / diagnose) and returns the cause, the fix steps, and the source manual page — or an explicit abstention when no exact manual exists.

For a full field diagnostic loop on a heat pump, use start_diagnostic → respond_to_diagnostic → close_diagnostic (see skill hvac-harnais-session).

MCP vs Chat API

AskMarcel exposes two separate integration surfaces — do not mix their protocols:

Surface	Endpoint	Protocol	Use case
MCP server (this repo)	`https://mcp.askmarcel.app`	JSON-RPC Streamable HTTP (`tools/call`)	Connect Claude, Cursor, VS Code, or any MCP client to HVAC tools
Chat API (web / mobile / extension)	`https://app.askmarcel.app/api/chat`	AI SDK v5 SSE (`UIMessageStream`)	Full conversational UI with streaming, tools, and document blocks

The MCP server does not use the AI SDK chat stream (text-delta, data-* parts). If you build a custom agent with the Vercel AI SDK, use MCP tools via JSON-RPC — not the web chat endpoint.

Authentication

Two supported methods (details in docs/authentication.md):

API key (Bearer): Authorization: Bearer YOUR_API_KEY
OAuth 2.0: discovery via https://mcp.askmarcel.app/.well-known/oauth-protected-resource

Claude Skills

The skills/ folder contains ready-to-use Agent Skills that wrap these tools into HVAC workflows:

hvac-error-lookup — turn a brand + error code into a sourced explanation and fix.
hvac-diagnostic — one-shot symptom lookup with citations (diagnose).
hvac-guided-diagnosis — multi-turn guided troubleshooting for air-to-water heat pumps (diagnose_guided).
hvac-harnais-session — Beta Harness session loop (start_diagnostic … close_diagnostic).

REST API SDK

For custom agents that call the REST API directly (not MCP), use the npm package @askmarcel/sdk — includes Harness session methods (startDiagnosticSession, respondToDiagnosticSession, …), guidedTurn() for POST /v1/diagnostic/turn, plus resolveModel() / getModelCoverage() / V2 diagnose.

License

Code and content in this repository (documentation, examples, skills) are released under the MIT License. The AskMarcel hosted service and its underlying data are proprietary and governed by the AskMarcel terms.

🇫🇷 En français

AskMarcel est un serveur MCP distant et hébergé (Streamable HTTP) qui connecte les agents IA à la documentation technique HVAC/RACH sourcée constructeur. Rien à installer : on pointe son client MCP sur l'endpoint et on s'authentifie. Chaque réponse cite le manuel et la page exacte plutôt que d'halluciner.

Endpoint : https://mcp.askmarcel.app
Nom registre : io.github.askmarcel/mcphvac
Manifeste : 1.3.1-beta.1 — 15 outils en production
Doc & clé API : https://app.askmarcel.app/developers
Marcel Inside (B2B) : https://askmarcel.app/fr/connecteurs
Tier Developer gratuit : 250 appels / mois
Couverture : 126 marques · 905 modèles · 400 000+ codes erreur indexés

Marcel Inside — branchez la base AskMarcel derrière votre chatbot, voicebot ou agent existant. Pilote 490€ · Business 149€/mois HT · tier Developer gratuit pour tester.

15 outils : 10 GA (search_technical_docs, get_procedure, get_error_code, get_product_sheet, get_pdf_page_snapshot, diagnose, diagnose_v2, resolve_model, get_model_coverage, diagnose_guided) + 5 session Harnais Beta (start_diagnostic, get_diagnostic, respond_to_diagnostic, close_diagnostic, get_diagnostic_summary).

Harnais Beta LIVE : lookup DB fabricant (technical_error_codes) au start_diagnostic, packs pac_air_eau / pac_air_air `0.0.1`, quota à la création de session seulement. Distinct de diagnose_guided (guidé legacy PAC Air/Eau, quota par tour).

Skills : lookup code erreur, diagnostic one-shot, guidé PAC, session Harnais — voir skills/.

SDK REST (npm) : @askmarcel/sdk — sessions Harnais + guidedTurn() + API v2.

Connexion rapide : créez une clé sur htt

Only the beginning is shown; read the rest in the repo

AskMarcel HVAC Technical Knowledge

Overview

PopNx MCP’s three pillars

What you can do with it

Install

Before you install

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Compared with others in Search & AI memoryi

Common questions

Alternatives

Context7

Codebase Memory

Exa

README from the maker

Marcel Inside — branch it behind your bot

Why AskMarcel

Harness session vs diagnose_guided

Tools

GA (10)

Beta — Harness session (5)

Quick start

1. Get an API key

2. Connect your MCP client

3. Ask a question

MCP vs Chat API

Authentication

Claude Skills

REST API SDK

Links

License

🇫🇷 En français

Harness session vs `diagnose_guided`