HVAC DIAGNOSTIC API · MANUFACTURER-SOURCED
FOR SOFTWARE, AI AGENTS, AND TECHNICAL SUPPORT
HVAC DIAGNOSTICS
FOR YOUR PRODUCT
Add sourced HVAC answers, agent tools, and guided sessions to your product — REST v1/v2, MCP, and Diagnostic Guide Beta. Applicable manual or explicit abstention.
- Manufacturer procedure cited — manual, page, section
- Abstention when no exact OEM source — no billed hallucination
- REST v1 lookup · v2 SKU provenance · Diagnostic Guide sessions · MCP 2025-06-18
curl https://api.askmarcel.app/v1/diagnostic \
-H "Authorization: Bearer ak_live_…" \
-d '{ "brand": "Mitsubishi", "model": "Ecodan PUHZ-W85", "error_code": "E7" }'TECHNICAL CONTRACT
Which API should I use?
v1 for broad lookup, v2 for strict SKU provenance, Diagnostic Guide sessions for guided diagnostics, MCP for your agents.
| Surface | Status | When to use | Limit |
|---|---|---|---|
| Broad lookup, automations, legacy integrations | Live | You need an error code, document search, or one-shot diagnostic without strict SKU provenance. | No strict SKU provenance; diagnostic/turn = legacy Air/Water HP guided flow. |
| Agents and software that must cite or abstain | Live | You must answer only from an exact manual for the SKU — otherwise abstain (not billable). | Not a stateful multi-turn session. |
| CMMS, FSM, cockpit — logged guided diagnostics | Beta | You want the Diagnostic Guide: safe next check, session journal, and resume by session_id. | Beta — 5 anchor brands, Air/Water + Air/Air HP; not full depth on 400k codes. |
| ChatGPT, Claude, custom agents | Live | Your agent calls MCP tools on mcp.askmarcel.app (protocol 2025-06-18). | Current OAuth: no diagnostic.run scope for Beta sessions. |
Two perimeters: Global lookup (400k+ codes) ≠ Diagnostic Guide Beta (panasonic, daikin, atlantic, mitsubishi-electric, gree, ~15% causal path). Do not promise Diagnostic Guide depth on the full corpus.
REST
Enrich an existing workflow with lookup, SKU resolution, and sourced responses.
Harness Beta
Run a guided session with model/SKU context, a journal, and explicit abstention when no safe check exists.
THE REAL BOTTLENECK
YOUR SOFTWARE KNOWS WHO, WHEN, WHERE.
NOT HOW TO FIX IT.
Your CMMS manages routes. Your ERP handles billing. Your AI agent answers customers. But at the critical moment — the error code on the unit — they still send the technician back to the hotline and 400-page PDFs. AskMarcel supplies sourced technical data while your product keeps its workflow, UX, and customer relationship.
Building in-house = a heavy project.
Collecting, cleaning, and structuring manuals from dozens of brands is a job in itself. Not a sprint.
Generic AI invents.
An LLM without domain data hallucinates an ohmic value. In the field, a wrong value means a return visit.
The data already exists — elsewhere.
AskMarcel has already crawled, structured, and verified it. You plug it in instead of rebuilding it.
ONE API, THREE PROMISES
MARCEL ANSWERS. YOUR TOOLS ACT.
From raw request to displayed procedure — manufacturer citation or explicit abstention.
Flexible input: code, model, or photo.
Send an error code, model reference, nameplate image in base64, or a natural language question. The API identifies context and normalizes the request. Endpoint POST /v1/diagnostic.
Two sockets, one afternoon
The API doesn’t “generate”. It queries 400,000+ sourced error codes. REST or MCP: your team plugs in within an afternoon. Every answer returns its exact source — manual, page, section.
Structured output: ready to display.
Clean JSON: step-by-step procedure, expected values (ohmic, pressure, temperature), spare part reference. Display it as-is in your UI, or pass it to your agent.
REST FOR YOUR SOFTWARE. MCP FOR YOUR AGENTS.
REST API
To integrate AskMarcel into an existing product.
- Endpoints: /diagnostic, /search, /error-codes, /procedure
- Bearer key auth, clear quotas, webhooks
- JS/TS SDK and OpenAPI provided
- Ideal for: CMMS, ERP, service portals, field mobile apps
MCP Server
To give any AI agent real HVAC expertise.
- Native MCP server: Claude, ChatGPT, Gemini, custom agents
- The agent "calls" Marcel as a tool, with sources
- Zero glue code: add the server, the agent can diagnose
- Ideal for: service copilots, support chatbots, internal assistants
{
"mcpServers": {
"askmarcel": {
"url": "https://mcp.askmarcel.app",
"headers": { "Authorization": "Bearer ak_live_…" }
}
}
}The same verified brain. Two ports. Choose the one that fits your stack.
DEVELOPER DOCUMENTATION
INTEGRATE IN ONE AFTERNOON.
Step-by-step guides, OpenAPI reference and platform tutorials — public and account-free.
Claude Desktop
The strongest case: remote MCP server at mcp.askmarcel.app with OAuth or API key. Claude calls diagnose and cites sources.
ChatGPT
UI form configuration in Developer Mode (no JSON to paste). Requires ChatGPT Plus/Pro/Business/Enterprise/Edu.
ElevenLabs
We do not integrate ElevenLabs. You connect your agent to our API — REST and/or MCP. No proprietary connector.
ManyChat
ManyChat does not support MCP — External Request HTTP only. Map the JSON response to display steps to the technician.
n8n / Make / Zapier
The most common adoption path: HTTP Request node to api.askmarcel.app/v1/diagnostic. Ideal for automating support workflows.
FOR DEVELOPERS & INTEGRATORS
Developers & AI agents
GIVE YOUR AGENT REAL DOMAIN EXPERTISE.
A generalist LLM guesses. Plug in the AskMarcel MCP server and your agent cites its sources: manual, page, value. Free Developer key (50 req/month), SDKs and OpenAPI ready — integrate in an afternoon.
{
"mcpServers": {
"askmarcel": {
"url": "https://mcp.askmarcel.app",
"headers": { "Authorization": "Bearer ak_live_…" }
}
}
}Decision-maker (service desk, e-commerce, publisher) rather than developer? Discover Marcel Inside (FR) →
WHY MARCEL, NOT AN LLM ALONE
Integration that doesn’t bill uncertainty
400,000+ branchable error codes
Manufacturer corpus exposed via REST and MCP — for your stack, not a marketing demo.
Sourced, always.
Page, section, value. Traceable answer — or explicit abstention.
All brands
Heat pumps, AC, boilers, stoves & pellets (Daikin, Viessmann, Mitsubishi, Palazzetti…).
Explicit abstention, measured on HVAC-Bench V1
Multi-market rollout without rebuilding.
0+
error codes
0
brands
0
referenced models
0
MCP tools
ONE PLUG FOR EVERY SCALE
PLUG IN. NO SURPRISE INVOICE.
Developer to test. Starter and Business activate self-serve: you're not buying volume, you're buying the right to build on it. White-label with the team.
We only bill what we know
A request is only counted when the answer is sourced and usable. Errors and empty responses are free.
Developer
Testing, POC, personal agents
- 50 requests/month — hard cap
- REST API + MCP server
- “Powered by AskMarcel” attribution
- Testing and POC — production not permitted
Starter
Indies, integrators
- Production use permitted
- REST + MCP, no attribution
- Webhooks & email support
- 500 requests/month included
Business
Service companies, CMMS/ERP vendors
- Contractual SLA & high rate limits
- Citable source — manual + page
- Priority support · unlimited seats
- Fair use: 5,000 requests/month
Scale / White-label
Manufacturers, distributors, large vendors
- Dedicated volume
- White-label
- Custom corpus
- Account manager
- Hard cap per tier (v4): no overage packs and no postpaid billing.
- 2 months free when paid annually upfront: Starter €290/year, Business €1,490/year.
- Developer: 50 requests/month, hard cap, no top-up. Built to test, not to ship.
- A single avoided site revisit (€150+) pays for a year of Starter.
Frequently asked questions
Everything you need to know before plugging in Marcel.
Need technical help? Contact our team
THE BRAIN IS READY. PLUG IT IN.
Create a free key in 2 minutes, or talk to the team for fleet / white-label setup.