Kaer runs an MCP server for your account. Connect an assistant you already use and it can run your workflows, ask your AI assistants, search your mail or plan a route, only with the permissions you give it. Use this page when you want to reach Kaer from another tool rather than from the Kaer app.
https://app.kaer.ai/api/mcpBefore you begin
- A paid Kaer plan. A key that only uses Mail needs an active mailbox instead.
- The assistant you want to connect, with permission to add custom connectors or MCP servers. In a company workspace, an admin may need to allow this.
- A clear idea of what the assistant needs. Give it only those permissions.
Choose how to connect
| Client | How it signs in |
|---|---|
| Claude, ChatGPT | OAuth: you approve in Kaer, no key to paste |
| Claude Code, Cursor, Codex, VS Code, Windsurf | An API key from Settings → Developers |
Connect with sign-in
Claude and ChatGPT connect with OAuth — there is no key to paste. Kaer shows what the assistant asks for, and you approve it.
Add Kaer as a connector
Claude: Settings → Connectors → Add custom connector. ChatGPT: Settings → turn on Developer mode, then add Kaer as a custom connector and choose OAuth. ChatGPT works on Plus, Pro, Business, Enterprise and Edu; a workspace admin may need to allow custom connectors.
Paste the endpoint
https://app.kaer.ai/api/mcp
Approve in Kaer
Kaer opens, shows the permissions, and asks you to connect. Tick only what the assistant needs — Run and draft workflows for your workflows.
Connect with a key
Coding agents use a key. Create one in Settings → Developers → New key, pick its permissions, and copy its setup. The key is shown once.
claude mcp add --transport http kaer https://app.kaer.ai/api/mcp \
--header "Authorization: Bearer kaer_sk_YOUR_KEY" \
--header "Accept: application/json, text/event-stream"VS Code, Windsurf and any other Streamable HTTP client take the same URL and headers.
Permissions
A key or connection can only reach the tools its permissions cover.
| Permission | What it allows |
|---|---|
| Mail search | Search and read mail, triage and send — each needs its own Mail grant |
| Calendar events | Read connected calendars |
| Models API | Call models from your code — see Models API |
| Kaer responses | Ask a Kaer model; pick the model or leave it on auto |
| Maps | Places, routes, transit and weather |
| Image & video | Generate media |
| Workflows | List, draft, run, follow, stop and approve workflows |
| AI assistants | List, hire, edit and ask your AI assistants |
| Computer Agent | Hand work to your computer workspace |
| Private tools & connectors | Let runs started this way use your stored credentials |
Everything on your plan ticks every permission your plan includes.
What assistants can do with workflows
- Find a workflow, start it with the input it needs, and wait for the result. A workflow added from Browse Workflows takes its template's inputs — plain text fills the main one.
- Draft a new workflow or change a draft. Publishing stays with you in Kaer.
- Stop a run that is still going.
- See which runs wait for an approval, and where you decide them.
- Approve or reject — only on workflows where you allowed assistants, and every approval is checked first. See Workflows → Approvals.
Ask a Kaer model
Kaer responses asks a model directly. Leave the model on auto and Kaer picks the right one for the request, or name any model from the model list. If that model does not answer, Kaer retries and moves to another so the call still completes; the result says which model answered.
Billing and limits
Everything an assistant does bills your credits at the same rates as the product. Each key carries up to 120 tool calls a minute. A retry with the same idempotency key returns the first result instead of running — or billing — twice.
See what a key has done
Settings → Developers has four pages:
| Page | Shows |
|---|---|
| Overview | The endpoint and a setup for each client |
| MCP keys | Your keys and their permissions. Create and revoke keys here |
| Tools | Every tool an MCP client can call, by the permission that unlocks it |
| Activity | Every tool call made with your keys |
Troubleshooting
The assistant cannot see a tool
The key or connection does not have the permission for it. Check Tools to find which permission unlocks the tool, then create a key with it or reconnect and tick it.
Calls fail after a while
Each key carries up to 120 tool calls a minute. Slow down, or spread the work across time. Calls also stop when your credits run out. See Billing and credits.
I lost a key
Keys are shown once and cannot be shown again. Revoke the lost key and create a new one.