Cortex
Cortex Docs · Coding · Productivity
Cortex is an open-source API knowledge layer that turns your API specifications into interactive documentation, typed SDKs, and MCP servers from a single config file. Point it at OpenAPI, AsyncAPI, GraphQL, gRPC, or OpenRPC sources. It produces three interfaces from one workflow: docs for humans, clients for apps, and tools for AI agents. Sound like a lot to maintain? It isn't. It's built for developers who want the pieces of API delivery to stay in sync instead of drifting apart.
About Cortex
What Is Cortex
Cortex is an API toolchain from Cortex Docs that generates everything a modern API needs from the definitions you already have. You bring your spec files, and it validates the contract, then outputs interactive documentation, typed client libraries in eleven languages, and an MCP server that lets AI coding agents call your endpoints with real context.
The problem it targets is familiar to anyone who maintains an API. Docs go stale, SDKs get hand-written and fall behind, and every AI assistant improvising an integration makes up request shapes it can't actually verify. Cortex treats your API contract as one source of truth and derives each surface from it, so the docs, clients, and agent tools describe the same thing.
The biggest limitation is the audience. This is a tool for developers and technical teams, not something a non-coder can pick up. No clicking your way to a portal here. It also runs on Node and expects you to be comfortable with a config file, a command line, and publishing to registries or hosting generated docs yourself. If you want a hosted, click-to-build API portal, you'll need to self-host and own that part.
Getting Started
- Install the Cortex CLI and run it against a project directory, or clone the repository if you plan to override templates.
- Create a
cortex.config.ymlfile and list your sources, such as an OpenAPI spec or a GraphQL schema, plus any Markdown notes you want folded into the output. - Choose which interfaces to generate: documentation, typed SDKs, an MCP server, or all three.
- Run the generate command and let Cortex validate the contract before it emits anything. Fix any spec errors it reports.
- Publish the clients to your own package registry and deploy the documentation wherever Node runs, or hand the MCP server to your AI coding tool.
Product Information
A quick look at Cortex's pricing, supported platforms, and performance.
Best for
The users, tasks, and scenarios where this tool fits best.
Users
- Backend and platform engineers
- Developer-tooling teams
- AI engineering teams
Tasks
- Generating client libraries
- Building a documentation site
- Exposing an API to agents
Scenarios
- Consolidating scattered API knowledge
- Onboarding a new integrating dev
- Reviewing contract changes. Validation happens before generation, so broken specs surface early rather than after a client ships.
Key features
Multi-Protocol Spec Support
Cortex accepts OpenAPI, AsyncAPI, GraphQL, gRPC, and OpenRPC sources in one project, so a mixed-protocol API doesn't need five separate toolchains. You list each source in the config. It validates the contract before generating anything. That step catches mismatched or incomplete definitions at the start, not at the point where a client breaks. If you're after an OpenAPI to SDK pipeline, or the same flow for a GraphQL schema, it's the same config either way.
Typed SDK Generation in Eleven Languages
The typed SDK generator produces native client libraries for TypeScript, Python, Go, Java, Kotlin, Ruby, PHP, C#, Rust, C++, and C. Each one follows its language's conventions, covering naming, types, and the native package manager. They ship with authentication, timeouts, streams, and retries built in. That's a real package, not a thin wrapper.
Interactive Documentation You Can Self-Host
Cortex produces a documentation site with searchable guides, interactive references, copy-ready code examples, and a live request builder. The reference stays matched to the API because it's generated from the spec. You can deploy the result anywhere Node runs, which keeps the docs under your control instead of tied to a vendor's hosting.
MCP Server Generation for AI Agents
Use it as an MCP server generator and every API operation becomes a typed tool, packaged alongside the source specs, documentation, and SDK references. The point is context. An agent can find the right interface, install the correct client, and write integration code without inventing request shapes, because the MCP server carries the contract as grounded resources. That turns a vague prompt into a real call against your actual API.
Open Templates With No Lock-In
The generation pipeline uses Eta templates under an MIT license, and any template can be exported and overridden. If the default output doesn't match your conventions, you change the template instead of fighting the tool. No lock-in. That's unusual for something that also offers a polished default experience.
Docs-as-Code Workflow
Cortex is designed to fit teams that treat documentation like code. Configs are reviewable, generation runs in a pipeline, and template overrides stay sparse and versioned. Combined with the layered source model, the API contract drives every output and nothing is hand-maintained twice.
Pros and cons
Pros
- One config generates docs, typed SDKs, and an MCP server, so they can't drift apart.
- Eleven language targets with native conventions, plus built-in auth, timeouts, and retries.
- MIT-licensed. Open, overridable templates too, so there's no vendor lock-in.
- MCP server generation gives AI coding agents typed, grounded tools instead of guesswork.
- Documentation stays self-hostable and deployable anywhere Node runs.
Cons
- It's aimed at developers. There's no no-code path, and you need to be comfortable with a config file and CLI.
- It runs on Node, so teams outside that runtime have to bring their own tooling.
- It generates and packages assets but leaves hosting, publishing, and registry setup to you.
- No paid support tier is published, which matters if you want an SLA or a vendor to call.
Frequently asked questions
Cortex generates interactive documentation, typed SDKs, and MCP servers from your API specifications. It's an API knowledge layer, so instead of maintaining docs, clients, and agent tools separately, you generate all of them from one source. Think of it as a gRPC client generator and an OpenAPI one in the same command.
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