MCP Server

MCP FAQ

Answers to the common questions about the Harny MCP server, its keys, and its costs.

Copy page

Is there OAuth?

Yes, for a coding assistant. The app's owner signs in on the Harny console, picks or creates the app and approves a coding assistant. The assistant then holds a token that lasts an hour and renews, instead of a copied key. Its address is not published yet, so connect with a key until it is. Keys work as before: send your key in the Authorization: Bearer <key> header. Connecting a person's own accounts is a separate step: configure_oauth.

Which key do I use?

Use the app key (starts with fsa_) for app-level tools such as provision_user, get_claim_link and get_setup_bundle. Use a person's key (starts with fsk_) for tools such as ingest_text, assemble_context, list_tools, configure_oauth and action_history. describe, get_snippet and diagnose accept any key. See Quickstart for setup and Keys and access for more.

Can the model choose the user?

No. Calls are scoped to the key's user. A person's key reaches only that person's memory and actions. See Tools for the full list.

Clients

Does it work with Claude Code and Cursor?

Yes. Claude Code and Cursor both connect over Streamable HTTP at https://api.harny.ai/v1/mcp/mcp. See Quickstart for the exact config.

Does it work with Replit?

Owner to confirm. This page does not list Replit as a supported client.

Behavior

What happens with no key?

The server offers only provision_app. Every other tool needs a key.

Can I use provision_app from a coding agent?

A coding agent that can run commands should follow https://harny.ai/auth.md instead. Its command never shows the key.

What happens over the rate limit?

The call answers 429 with Retry-After. MCP calls follow the same limits and refusals as the REST routes they wrap. See Limits.

Can the server search the web?

No. The server exposes only the tools listed on the Tools page, and none of them search the web.

Data and cost

How do I erase a person?

Call DELETE /v1/users/{user_id}/data. See the Memory API docs for details.

Does it cost anything extra?

The first 500 monthly-active end users are free. A monthly-active end user is a person with at least one memory read, one memory write or one recorded agent action in a calendar month. Stored but dormant users are free. Above 500, the price is $0.30 per monthly-active end user per month, flat.

Where is the REST API?

The MCP tools wrap REST routes. ingest_text and assemble_context wrap POST /v1/vault/ingest/text and POST /v1/context/assemble. The Memory API lives at https://api.harny.ai/v1/memory. See the Memory API docs.