Read waivers, signed participants and check-ins in Otter Waiver. Hosted by usefulapi: connect it to Claude, ChatGPT, Cursor or any MCP client.
Turn on the Otter Waiver connector, then ask in plain words. The AI picks the tools.
For tour, rental and event operators that collect signed waivers with Otter Waiver.
List the waivers of the account and filter by event name or title. See which waivers are in draft, active or inactive.
Open one waiver to read its full text, settings and extra fields. Check the wording before an event.
List the 50 latest participants who signed a waiver, with the sign times. Open one participant to read the details.
List the 50 latest check-ins to see who arrived at today's activity.
The login page asks for your Client ID and Client Secret.
Find both in app.ottersign.com → Settings → Account and Preferences → API keys (use Show). They are used only to call the API on your behalf and to derive a private account id; they are never shown to anyone.
Team and Enterprise: an Owner adds the connector for the organization first.
No Add custom MCP server option? It depends on your account or workspace settings: see OpenAI's guide.
Run this command, then run /mcp in Claude Code to log in:
Add to Cursor or add this to ~/.cursor/mcp.json:
{
"mcpServers": {
"otter-waiver": {
"url": "https://otter-waiver.usefulapi.io/mcp"
}
}
} Add to VS Code or add this to .vscode/mcp.json:
{
"servers": {
"otter-waiver": {
"type": "http",
"url": "https://otter-waiver.usefulapi.io/mcp"
}
}
} Run these commands. The second one opens the login page:
Windsurf, Cline, Zed and other MCP clients: add this URL as a remote MCP server (Streamable HTTP). The client then opens the login page in your browser.
Add only the URL. Do not add an Authorization header or an API key to the client config. The server signs you in with OAuth: the login page asks for your Client ID and Client Secret. If the config has such a header, remove it: some clients then send that header instead of the login token, and every call fails with 401.
| Plan | Price | Limit |
|---|---|---|
| Free | $0 | 50 tool calls / month |
| Proper user | $9/mo · $90/yr | 10,000 tool calls / month |
| Pro+per user | $39/mo · $390/yr | 100,000 tool calls / month |
Each paid plan covers this Otter Waiver server only. Ask your AI to run otterwaiver_upgrade and choose Pro or Pro+, billed monthly or yearly (it returns a Stripe Checkout link). If you already have Pro, ask to change it to Pro+. The change requires your confirmation, keeps your billing interval and charges the price difference for the rest of the period immediately. Cancel any time with otterwaiver_cancel_subscription: your paid plan continues to the end of the paid period, with no refund for the current period, and asking to resume the same plan with otterwaiver_upgrade before then undoes the cancel. Or write to [email protected].
otterwaiver_list_waiversotterwaiver_get_waiverotterwaiver_list_latest_participantsotterwaiver_list_latest_checkinsotterwaiver_get_participantotterwaiver_usage_statusotterwaiver_request_featureotterwaiver_upgradeotterwaiver_cancel_subscriptionList the waivers and their status. Read the full text of a waiver. See who signed in the last days. Review the latest check-ins. See what you can do for the details.
No. usefulapi is an independent service. It is not affiliated with or endorsed by Otter Waiver. The server calls the Otter Waiver API with your own Otter Waiver access, so it sees only the data that your account can see.
Yes. In Claude, add this server's URL as a custom connector. In ChatGPT, add it as a custom MCP server in Plugins. Then log in once. Cursor, VS Code, Claude Code and Codex work too. See the setup steps.
The login page asks for your Client ID and Client Secret. See Before you connect for where to find them.
No. Add only the URL. Do not add an Authorization header or an API key to the client config. The server signs you in with OAuth: the login page asks for your Client ID and Client Secret. If the config has such a header, remove it: some clients then send that header instead of the login token, and every call fails with 401.
The login stores them encrypted in the authorization grant of your connection. The server uses them to call the Otter Waiver API for you and to derive a private account id for usage metering. usefulapi does not show them on any page or in any reply. To stop all access, remove the connector and change or delete these credentials in Otter Waiver.
All 5 Otter Waiver tools are marked read-only.
The Free plan gives 50 tool calls / month. Pro costs $9/mo or $90/yr, with 10,000 tool calls / month. Pro+ costs $39/mo or $390/yr, with 100,000 tool calls / month. Each subscription covers this Otter Waiver server only. Cancel any time: your paid plan then runs to the end of the paid period. Run otterwaiver_usage_status to see how many calls you used.
Ask the AI to run otterwaiver_upgrade and choose Pro or Pro+, billed monthly or yearly: it returns a Stripe Checkout link. If you already have Pro, ask to change it to Pro+. After you confirm, your existing subscription changes in place, keeps its billing interval and charges the price difference for the rest of the period immediately. To cancel, run otterwaiver_cancel_subscription. Your paid plan continues to the end of the paid period.
Tell the AI what you wanted to do. It can send the request with otterwaiver_request_feature. We store the text with the server name, the type of AI client and the tool you tried, not with your account, and read every request when we plan new tools. You can send up to 5 requests per day.
Any client that supports remote MCP servers (Streamable HTTP) with OAuth login: Claude (web and desktop), Claude Code, ChatGPT, Codex, Cursor, VS Code, Windsurf and others.
This is a Model Context Protocol endpoint — meant to be connected from an AI client, not opened in a browser. An invalid_token response at the URL is the auth gate working as designed; clients authenticate automatically.
Need a tool this server does not have, or a connection to another system? We build custom integrations and MCP servers.