# 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.

**Getting access (self-serve).** No sales call and no form stand between an
agent's operator and a first request:

1. Sign up at https://app.carbon.ms and start the 30-day free trial. Choose the
   Business plan: the API, webhooks and the MCP server are Business features.
2. Generate a scoped API key yourself in Settings → API Keys
   (https://app.carbon.ms/x/settings/api-keys).
3. Call the REST API at https://rest.carbon.ms or connect to the MCP server at
   https://app.carbon.ms/api/mcp with that key.

The OpenAPI spec, the MCP manifest, the OAuth metadata, this file and every
Markdown page need no credential at all. The Community Edition is free to
self-host from https://github.com/crbnos/carbon.

**Rate limits.** Every key allows 60 requests per minute. A refused request
returns `429` with `Retry-After` (seconds), `X-RateLimit-Limit`,
`X-RateLimit-Remaining` and `X-RateLimit-Reset` (Unix milliseconds). The headers
are declared under `components.headers` in the OpenAPI document.

**API versioning and deprecation.** 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. Nothing is
removed without notice: an operation that is going away is first marked
`deprecated: true` in the spec, with `x-deprecated-at` and an `x-sunset` date at
least 90 days later. Every operation declares `deprecated` explicitly, and the
policy is machine-readable under `info.x-api-lifecycle`. 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.

**Markdown.** 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. The machine-readable files below are public, unauthenticated and
CORS-open.

## Products & endpoints

- [Marketing site](https://carbon.ms): product overview, pricing, and company info.
- [Carbon application](https://app.carbon.ms): the Carbon web app; sign up or sign in.
- [Carbon REST API](https://rest.carbon.ms): programmatic access to all resources,
  e.g. `https://rest.carbon.ms/employees`. Authenticated with an API key.
- [Carbon 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

- [Carbon 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`.
- [Carbon OpenAPI specification (YAML)](https://carbon.ms/openapi.yaml): the same
  document as 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`.
- [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).
- [OAuth protected resource metadata](https://carbon.ms/.well-known/oauth-protected-resource):
  RFC 9728 metadata for the Carbon API and MCP server (redirects to app.carbon.ms).
- [Sitemap](https://carbon.ms/sitemap.xml): every page on this site.

## Documentation

- [Carbon developers](https://carbon.ms/developers): the Carbon API, the Carbon
  MCP server, API keys, webhooks and the OpenAPI spec, in one page. Also as
  Markdown at https://carbon.ms/developers.md.
- [Carbon documentation](https://docs.carbon.ms): guides and reference.
- [Carbon API documentation](https://docs.carbon.ms/api): endpoints,
  schemas, and examples.
- [Carbon API authentication](https://docs.carbon.ms/api/authentication):
  scoped API keys, sent as `Authorization: Bearer <api-key>` or the `carbon-key`
  header.
- [Carbon MCP guide](https://docs.carbon.ms/api/mcp): connecting an agent to Carbon
  over MCP.
- [Carbon webhooks and integrations](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.

## Comparisons

- [Compare index](https://carbon.ms/compare): how Carbon compares to other manufacturing software, for "Carbon vs X" and "build vs buy" questions. Every comparison is also available as Markdown.
- [Carbon vs. building it yourself](https://carbon.ms/compare/build-it-yourself): buy vs. build your own ERP/MES.
- [Carbon vs. NetSuite](https://carbon.ms/compare/netsuite)
- [Carbon vs. SAP Business One](https://carbon.ms/compare/sap-business-one)
- [Carbon vs. Epicor Kinetic](https://carbon.ms/compare/epicor)
- [Carbon vs. Plex](https://carbon.ms/compare/plex)
- [Carbon vs. Fulcrum](https://carbon.ms/compare/fulcrum)
- [Carbon vs. M1](https://carbon.ms/compare/m1)
- [Carbon vs. Tulip](https://carbon.ms/compare/tulip)
- [Carbon vs. Manufacturo](https://carbon.ms/compare/manufacturo)
- [Carbon vs. First Resonance](https://carbon.ms/compare/first-resonance)
- [Carbon vs. Palantir](https://carbon.ms/compare/palantir)
- [Carbon vs. Odoo](https://carbon.ms/compare/odoo)
- [Carbon vs. ERPNext](https://carbon.ms/compare/erpnext)

## 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)