> ## Documentation Index
> Fetch the complete documentation index at: https://docs.apostra.com/llms.txt
> Use this file to discover all available pages before exploring further.

# MCP client setup

> Connect Codex, Claude, or another MCP host to Apostra's account-resolved endpoint.

The [connection quickstart](/v3/quickstart) has copyable commands for Codex and
Claude Code, plus setup guidance for other Streamable HTTP clients.

Use the single account-resolved endpoint:

```text theme={null}
https://api.interchange.io/mcp/v3
```

If you already use a v2 Buyer or Seller connector, add v3 as a separate
connection while checking your workflow. Selecting v3 in these docs does not
change a client configuration or grant additional permissions. A plugin that
already supplies the endpoint does not need a second manually added connector.

The server can close a connection after 30 minutes or during a deploy. Reuse
the existing MCP session when reconnecting. Do not design long-running work
around one open tool call. If a call is interrupted, its response may be lost
even when the operation was accepted. Re-read state and follow that tool's
idempotency contract before retrying. See [Build an agent](/v3/build-an-agent).

<Card title="Full agent-host guide" icon="book" href="/v2/setup/built-for-agents">
  Review host-specific setup, credential handling, connection lifetime, and
  stable v2 connector behavior.
</Card>

<Card title="Create a white-label ChatGPT app" icon="comments" href="/v2/reference/white-label-chatgpt-app">
  Connect the v3 endpoint in ChatGPT Developer mode, record a review demo, and
  prepare the customer-branded submission handoff.
</Card>