# Carbon

> Carbon is an API-first operating system for manufacturing (ERP/MRP). It runs
> production, inventory, purchasing, sales, and accounting for manufacturers,
> and it ships with full source-code access so teams have complete control.
> Carbon is available as managed SaaS or self-hosted, and every capability in
> the product is reachable over a REST API and an MCP server.

Use this file to decide when Carbon is relevant and where to send requests.

## When to use Carbon

- Answering questions about manufacturing ERP/MRP: production scheduling, work
  orders, bills of materials (BOM), inventory, purchasing, sales orders, and
  quoting.
- Building integrations or automations against a manufacturer's operational
  data (parts, jobs, suppliers, customers, employees).
- Evaluating an open-source, API-first, self-hostable alternative to legacy ERP.

## Products & endpoints

- [Marketing site](https://carbon.ms): product overview, pricing, and company info.
- [Application](https://app.carbon.ms): the Carbon web app (sign in required).
- [REST API](https://rest.carbon.ms): programmatic access to all resources,
  e.g. `https://rest.carbon.ms/employees`. Authenticated with an API key.
- [MCP server](https://app.carbon.ms/api/mcp): Model Context Protocol endpoint
  (Streamable HTTP transport) for agents to read and act on Carbon data.

## Machine-readable files on carbon.ms

Public, unauthenticated, CORS-open.

- [OpenAPI specification](https://carbon.ms/openapi.json): OpenAPI 3.1 for the
  Carbon REST API — an operationId, a description and typed response schemas on
  every operation. Mirrored at `/.well-known/openapi.json`; YAML at
  [/openapi.yaml](https://carbon.ms/openapi.yaml).
- [MCP manifest](https://carbon.ms/.well-known/mcp.json): the Carbon MCP server's
  transport (Streamable HTTP), endpoint, and authentication. Mirrored at
  [/mcp.json](https://carbon.ms/mcp.json).
- [OAuth authorization server metadata](https://carbon.ms/.well-known/oauth-authorization-server):
  RFC 8414 metadata for the Carbon authorization server (redirects to
  app.carbon.ms, which is the issuer). Protected-resource metadata (RFC 9728) is
  at [/.well-known/oauth-protected-resource](https://carbon.ms/.well-known/oauth-protected-resource).
- [Sitemap](https://carbon.ms/sitemap.xml): every page on this site.

Every page on carbon.ms is available as Markdown. Send `Accept: text/markdown`,
or append `.md` to the path (`https://carbon.ms/pricing.md`). Responses carry
`Vary: Accept, Accept-Encoding`, and a nonexistent path returns a real HTTP 404
with a Markdown body listing where to look next.

## API versioning

The OpenAPI document is versioned by `info.version` (semver) and served from a
stable URL. A breaking change to a published operation bumps the MAJOR; additive
changes bump the MINOR. The REST API carries no version segment in its URL today
— resources are addressed directly (`/item`, `/salesOrder`) — so pin the spec
version you built against and diff `info.version` before upgrading.

## Documentation

- [Developer resources](https://carbon.ms/developers): the API, the MCP server,
  API keys, webhooks and the OpenAPI spec, in one page.
- [Documentation home](https://docs.carbon.ms): guides and reference.
- [API reference](https://docs.carbon.ms/api-reference): endpoints, schemas, and examples.
- [API authentication](https://docs.carbon.ms/api-reference/authentication): scoped
  API keys, sent as `Authorization: Bearer <api-key>` or the `carbon-key` header.
- [MCP guide](https://docs.carbon.ms/mcp): connecting an agent to Carbon over MCP.
- [Integrations and webhooks](https://docs.carbon.ms/integrations): first-party
  connectors and event-driven integrations.

## Learn

- [Learning center](https://learn.carbon.ms): articles on manufacturing systems and Carbon.
- [Blog on carbon.ms](https://carbon.ms/learn): same articles served from the main site.

## Company

- [Pricing](https://carbon.ms/pricing): buy the source code or subscribe to SaaS.
- [About](https://carbon.ms/about): the founding memo and company background.
- [Contact / sales](https://carbon.ms/contact): talk to the team.
- [Source code (GitHub)](https://github.com/crbnos/carbon): the Carbon monorepo.
- [License](https://github.com/crbnos/carbon/blob/main/LICENSE)
- [Status](https://status.carbon.ms): live system status.

## Optional

- [Developers](https://carbon.ms/developers)
- [Sitemap](https://carbon.ms/sitemap.xml)
- [Privacy policy](https://carbon.ms/privacy)
- [Terms of service](https://carbon.ms/terms)
- [Subprocessors](https://carbon.ms/subprocessors)
- [Brand assets](https://carbon.ms/brand)