# MCP server for AI assistants | Corvair Knowledge Substrate

Connect Claude, Codex, ChatGPT or Grok to the Corvair Knowledge Substrate MCP server with one address and one sign-in, or call the HTTP API from your own code.

Canonical: <https://corvair.ai/cks/connect.html>

Use Corvair Knowledge Substrate from the AI assistant you already use, or from your own software. Sign in once, then search your knowledge with the passages behind each answer, read and add to memory, work with your Vault files and check warrants.

**Coming with the rebuilt Knowledge Substrate.** The MCP server, access keys and the command line are published when the rebuild is complete. Until then, this page shows how they will work.

## Paste this into your assistant

Add Corvair Knowledge Substrate to your assistant with one address. "Connector", "app", "plugin" and "MCP server" all mean the same thing here: the Model Context Protocol (MCP) is the open standard AI assistants use to reach outside services.

`https://cks.corvair.ai/mcp`

## Choose your assistant

[**Claude** Web, desktop, mobile and Claude Code Not yet tested](https://corvair.ai/cks/connect.html#claude)

[**Codex** Command line, desktop app and IDE extension Not yet tested](https://corvair.ai/cks/connect.html#codex)

[**ChatGPT** Custom plugin with an MCP server Not yet tested](https://corvair.ai/cks/connect.html#chatgpt)

[**Grok** Grok Build Not yet tested](https://corvair.ai/cks/connect.html#grok)

[**Other MCP clients** Any assistant that supports remote MCP servers Settings below](https://corvair.ai/cks/connect.html#other-clients)

[**Your own software** The HTTP API, with an access key See "Use the API"](https://corvair.ai/cks/connect.html#api-start)

"Tested by Corvair" means Corvair has connected that assistant and used it. Other guides follow the vendor's own instructions, which can change.

### Claude

1. In Claude, open **Settings**, then **Connectors**, and choose **Add custom connector**.
2. Name it **Corvair Knowledge Substrate** and paste the address above. Leave the advanced settings empty.
3. Choose **Connect**. A Knowledge Substrate sign-in page opens: sign in and choose the permissions to grant.
4. In a chat, turn the connector on from the tools menu.

In Claude Code, add it from a terminal:

Claude Code

```
claude mcp add --transport http corvair-cks https://cks.corvair.ai/mcp
```

Then run /mcp in Claude Code and sign in when asked.

### Codex

(Not yet tested) Corvair has not connected Codex to the Knowledge Substrate. These steps follow Codex's own public instructions, which can change: [Codex documentation](https://learn.chatgpt.com/docs/extend/mcp?surface=cli).

The command line, the desktop app and the IDE extension share one list of servers, so add it once. From a terminal:

1. Add the server: run the first command below.
2. Sign in: run the second command. A Knowledge Substrate sign-in page opens in your browser: sign in and choose the permissions to grant. On a machine with no browser, add `--no-browser`, open the address it prints, sign in, and paste the full address you land on back into the terminal.
3. Check it: run `codex mcp list`, or type `/mcp` in the `codex` terminal screen.

Codex command line

```
codex mcp add corvair-cks --url https://cks.corvair.ai/mcp
codex mcp login corvair-cks
```

Leave the client ID and secret options out.

In the desktop app, open **Settings**, then **MCP servers**, and choose **Add server**. In the IDE extension, open the gear menu, then **MCP servers**, and choose **Add server**. In either, enter the name **corvair-cks**, choose **Streamable HTTP**, enter the address above, save, and restart. Then choose **Authenticate** in the server list.

### ChatGPT

(Not yet tested) Corvair has not connected ChatGPT to the Knowledge Substrate. These steps follow ChatGPT's own public instructions, which can change: [ChatGPT documentation](https://developers.openai.com/api/docs/mcp). The ChatGPT instructions have been reorganised more than once, so the menu names may differ from what you see. Which plans and workspaces can add a custom server is set by OpenAI and, in a workspace, by its administrator.

1. In ChatGPT, open the Plugins page (`chatgpt.com/plugins`), choose the plus button, and choose **Add custom MCP server**.
2. Name it **Corvair Knowledge Substrate**, paste the address above, and choose OAuth as the sign-in. Leave the client ID and secret empty.
3. Read the warning ChatGPT shows for servers it has not reviewed, choose **I understand and want to continue**, then **Create as a plugin**.
4. Install the plugin. A Knowledge Substrate sign-in page opens: sign in and choose the permissions to grant.
5. Try it in a chat.

### Grok

(Not yet tested) Corvair has not connected Grok to the Knowledge Substrate. These steps follow Grok's own public instructions, which can change: [Grok documentation](https://docs.x.ai/build/features/mcp-servers).

xAI's documentation describes adding a remote server to Grok Build, its terminal tool. It does not describe adding a custom MCP server in the Grok chat app, so there is no guide for chat here.

1. In a terminal, add the server with the command below.
2. The first time it is used, Grok Build opens a browser: sign in to the Knowledge Substrate and choose the permissions to grant.
3. Inside a Grok Build session, type `/mcps` to see the server, sign in again, or turn it on and off. Outside a session, `grok mcp list` shows it.

Grok Build

```
grok mcp add --transport http corvair-cks https://cks.corvair.ai/mcp
```

Do not add a header option: the sign-in is the browser one.

## Sign-in and permissions

Sign-in happens on the Knowledge Substrate's own page, with the same account you use in its screens. You then choose what the assistant may do.

| Permission | What it allows |
| --- | --- |
| **Read** | Search knowledge and see the passages behind answers, read memories and learnings, list Vault files, and check warrants. |
| **Write** | Add documents and websites, record conversations, upload files, and ask for a warrant to be sealed. |
| **Research** | Run research that uses the knowledge base's research budget, such as filling a gap or crawling a site again. |

- The assistant never sees your password.
- Every request sees only what you are allowed to see, in the knowledge bases you belong to.
- Anything that deletes or erases returns a preview first. You confirm it in the Knowledge Substrate's screens, not in the chat.
- The connection renews on its own. Connecting again with the same permissions does not ask again.

## Your first session

Try these in your assistant once it is connected.

Starter requests

```
Search my company library for our warranty terms. Show each answer
with the passage it came from and its source.

What do we know about Halvorsen Foods? List the account's memories
and learnings. Read only.

List the files in my Vault that are on hold, with the reason for each.
```

Sample account names.

## Settings for any MCP client

| Setting | Value |
| --- | --- |
| Address | `https://cks.corvair.ai/mcp` |
| Transport | Streamable HTTP |
| Sign-in | OAuth 2.1 with PKCE and dynamic client registration. Leave the client ID and secret empty. |
| Permissions | `read`, `write`, `research` |
| Discovery | `https://cks.corvair.ai/.well-known/oauth-protected-resource/mcp` |
| Access keys | For clients that only accept a key or a header (below). |

### Smaller connectors, for clients with a tool limit

Each of these addresses carries one part of the tools. Add only the ones you need.

| Address | Tools |
| --- | --- |
| `https://cks.corvair.ai/mcp/knowledge` | Search, cited answers, documents, claims, topics and sources |
| `https://cks.corvair.ai/mcp/memory` | Conversations, context, memories and learnings |
| `https://cks.corvair.ai/mcp/vault` | Files, versions, uploads and generated files |
| `https://cks.corvair.ai/mcp/warrants` | Seal, check and export warrants, and read ledgers |

Each tool calls the same API route a program would, so the same permissions apply everywhere. The full list of tools is in the [API reference](https://corvair.ai/cks/api.html).

### Access keys

For a client or a script that cannot sign in through a browser: in the Knowledge Substrate's screens, open **Account**, choose **Keys**, then **Make a key**. Name it, choose its permissions and when it expires: after 30, 90 or 365 days, or never. The key is shown once. Send it as a header:

Header

```
Authorization: Bearer cks_live_…
```

A key cannot change administrator settings. Those need a person signed in.

## Use the API from your own software

Everything an assistant can do, your own software can do through the HTTP API. All routes are versioned and answer in JSON.

| Item | Value |
| --- | --- |
| Base address | `https://cks.corvair.ai` |
| Sign-in | An access key, or the token from a person's sign-in, as `Authorization: Bearer` |
| Changes | Anything that deletes or erases returns a preview with a token. Send the token back to apply it. |
| Long work | Returns at once with a job you can check, or a notice sent to your address when it finishes. |
| Reference | Every route with its parameters, in the [API reference](https://corvair.ai/cks/api.html), and as an OpenAPI description to download. |

A first search

```
curl -X POST -H "Authorization: Bearer $CKS_KEY" \
  -H "Content-Type: application/json" \
  -d '{"question": "What does the warranty exclude?", "top_k": 5}' \
  https://cks.corvair.ai/query/$KB_ID/search
```

Returns passages ranked best first, each with its source, tier and topics.

## Good to know

- **Costs.** Research, and anything that calls an AI model, draws on the knowledge base's budget. Each tool says whether it does.
- **Long work.** Research, crawls and exports carry on after the chat is closed.
- **One record.** Your assistants, your applications and the screens all use the same knowledge bases, memory and Vault.
- **Activity.** The history records which tool was called and when, not what was said.
- **Disconnect.** In the screens, open **Account**, then **Connected apps**, and choose **Remove**. It takes effect within a minute. Keys are listed there too.

## Troubleshooting

| What you see | What to do |
| --- | --- |
| No Knowledge Substrate tools | Check that the connector is added, turned on for this chat and signed in, and that the address ends in `/mcp`. Restart the assistant if needed. |
| The wrong knowledge base | The assistant is signed in to another account. Remove the connection and connect again with the right one. |
| `scope_required` | The tool needs a permission you did not grant. Connect again and grant it. |
| A budget message | The knowledge base's research budget is used up for now. An administrator can raise it. |
| A certificate warning | Check the address is exactly `cks.corvair.ai`, and contact us. Do not turn off security checks. |
| Still stuck | Note the exact error, the assistant's name and the time, and [contact us](https://corvair.ai/contact.html). |