Code Mode is now available — two fixed tools to call any API without flooding your LLM context.
How it worksFeaturesPricingRoadmap
Create my MCP server →

Any API.
Connected to any LLM.
In 30 seconds.

Today, making an LLM talk to your API means writing an MCP server — one per API. We automate that: upload your OpenAPI spec, get a hosted MCP URL that works instantly in Claude, ChatGPT, Mistral, or any compatible client.

EU-hosted - GDPR-native - Your credentials never touch a US cloud
Create my MCP server — free →See how it works

No card required. 100 endpoints · 5,000 calls/month.

1 Spec in

2 Generated MCP server

GETlist_booksready
GETget_random_bookready
GETget_bookready
PATCHpatch_bookready
DELETEdelete_bookready
POSTcreate_bookready
GETget_inventoryready
+ 2 more
9 tools generated·—·v0.1
How it works

Three steps. Zero code.

You keep your API. We translate OpenAPI → MCP in real time — auth, schemas and errors preserved.

01

Import your OpenAPI

JSON or YAML, or a public HTTPS URL. OpenAPI 3.x and Swagger 2.0 — Postman collections coming soon.

library-openapi.json
9 endpoints3.1.0
02

We generate the MCP server

Every endpoint becomes a properly typed MCP tool. Auth is injected server-side, automatically.

// generated tool
tool list_books {
  genre?: string
  author?: string
  q?: string
} // from GET /books
03

Connect your LLM

Paste the MCP URL into your LLM (Claude, ChatGPT, Mistral, or any compatible client). Instant — and the URL stays stable when you update your spec.

CClaudeconnected
GChatGPTconnected
MMistralconnected
Before / after

One week of dev vs. thirty seconds.

The spec already exists. MCP boilerplate is repetitive and costly to maintain. Let us generate it — cleanly, on every release.

WITHOUT corelayer0

You write the MCP server by hand. Per API. Per version.

  • Redeclare every endpoint in TypeScript or Python
  • Rewire auth, types, pagination, error handling
  • Maintain it manually on every spec change
  • Deploy, monitor, manage secrets yourself
~1 week per API · ×N APIs

WITH corelayer0

You provide the spec. You get the MCP URL. Done.

  • Automatic generation from OpenAPI 3.x
  • Auth injected automatically
  • Update your spec anytime — stable MCP URL, connected LLMs don't break
  • EU-hosted (France 🇫🇷 - OVHcloud)
30 sec · any API
Under the hood

Everything you'll never have to write again.

Zero MCP infrastructure to maintain. Your API stays yours — auth, data, logic.

⌘

Auth injected automatically

Credentials never reach the LLM — they're injected server-side on every outbound call. No token, static Bearer, or OAuth2 Client Credentials — your choice.

No tokenpublic APIsavailable
API key / Bearerheader injectionavailable
OAuth2 Client Credentialsmachine-to-machineavailable
↻

Spec always in sync

Paste your JSON or point to an HTTPS URL. Update your spec anytime — the MCP URL stays stable, your connected LLMs don't disconnect.

30s
to generate an MCP server
stable
URL across spec updates
∞
endpoints supported
⊞

Endpoint filtering

Enable or disable each endpoint from the dashboard. Expose exactly what your LLM needs — nothing more.

◐

Native OAuth 2.1 per project

Each MCP server is its own Authorization Server. MCP clients connect without pre-shared tokens — PKCE S256, dynamic client registration, automatic rotation.

⌂

EU sovereignty by design

Hosted on OVHcloud (France 🇫🇷, EU), secrets encrypted under an EU-controlled KMS. Your data and credentials never leave the European Union — and never fall under the US CLOUD Act. GDPR-native, no transatlantic data transfer to assess.

⇄

A gateway between your APIs and every LLM

We speak MCP on the LLM side, plain HTTP/REST on your side. No agent to deploy, no SDK to integrate. Your LLM clients see tools; your API sees standard HTTP requests.

LLM CLIENTSClaude · Mistral Vibe · ChatGPT
— mcp →
CORELAYER0gateway · auth · MCP
— https →
YOUR APIunchanged
⚲

Secure by default

Credentials are never stored in plaintext. Argon2-hashed tokens, AES-256-GCM encryption under KMS, EU-only infrastructure.

Now available

What's already live.

Features already in production and ready to use today.

⊞Available

Classic Mode

One MCP tool per enabled endpoint. The LLM sees every operation directly in context. Simple, explicit — optimal below 20 endpoints.

λAvailable

Code Mode

Two fixed tools — search() to explore the OpenAPI spec, execute() to call the API. Constant token cost (~1,000 tokens) regardless of API size. Recommended above 20 endpoints.

↓Available

Spec import (JSON & YAML)

Paste your JSON or YAML spec, or point to a public HTTPS URL. OpenAPI 3.x and Swagger 2.0 supported. The spec is parsed server-side — it never enters the LLM context.

⚿Available

API token management

Static Bearer token encrypted server-side, injected automatically on every outbound call. The LLM never sees your credentials.

On the roadmap

What's coming.

Our priority: broader format support and full observability of every LLM call.

◆Soon

Postman Collections

Import your Postman collections directly — no manual OpenAPI conversion.

◐Soon

Native observability

Structured logs, OpenTelemetry traces, replays. See what each LLM called, with which arguments, and what came back.

↺Soon

Git sync / webhooks

Connect your repo or a webhook. On every push, MCP tools regenerate automatically — the URL stays stable.

Pricing

Public Beta — everything is free.

Free

0€/ during the Beta

Free for the entire Public Beta (v1.0 planned Q4 2026). No card, no commitment.

  • 1 MCP project
  • Up to 100 active endpoints
  • 5,000 calls / month
  • Native OAuth 2.1 AS · PKCE · auto rotation
  • AES-256-GCM encryption under an EU sovereign KMS
  • EU-only infrastructure (France 🇫🇷)
Start for free

Early-adopter bonus: accounts created before v1.0 keep Pro quotas for 6 months after launch — automatically, no action required.

Your API. Every LLM.
No MCP server to write.

Generate my MCP server →

OpenAPI → MCP, in 30 seconds.
Built in Paris 🇫🇷 & hosted in the EU 🇪🇺

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OVHcloud Startup Program Member
v0.1 · beta