Read SIGNL4 alerts, teams, users and duty schedules; raise, acknowledge, close and annotate alerts. For on-call and operations teams who page their staff with SIGNL4. Hosted by usefulapi — connect from Claude, ChatGPT, Cursor, or any MCP client.
Team and Enterprise: an Owner adds the connector for the organization first.
Run this command, then run /mcp in Claude Code to log in:
Add to Cursor or add this to ~/.cursor/mcp.json:
{
"mcpServers": {
"signl4": {
"url": "https://signl4.usefulapi.io/mcp"
}
}
}Add to VS Code or add this to .vscode/mcp.json:
{
"servers": {
"signl4": {
"type": "http",
"url": "https://signl4.usefulapi.io/mcp"
}
}
}No Add custom MCP server option? It depends on your account or workspace settings: see OpenAI's guide.
Run these commands. The second one opens the login page:
Other MCP clients (Windsurf, Cline, Zed and more): add the URL as a remote MCP server (Streamable HTTP). The client then opens the login page in your browser. Do not add an Authorization header: see Before you connect.
The AI searches alerts by team, status, creation time, text or external id, and opens one for its status, severity and history.
signl4_list_alerts signl4_get_alert
The AI reads whether users are on or off duty per team, the planned duty schedules with stand-ins and shifts, and the duty summary of a team.
signl4_get_duty_status signl4_list_duty_schedules signl4_get_duty_summary signl4_list_team_users
The AI reads the ordered timeline of an alert: notifications, acknowledgements, annotations and escalations, and who responded.
signl4_get_alert_timeline signl4_get_alert
The AI reads acknowledged, closed and unhandled alert counts per team over several periods, overall and per category.
signl4_get_alert_report signl4_list_teams
The AI raises a new alert in a team, with a category if you name one. Everyone on duty is paged, so confirm before it runs.
Changes data · signl4_raise_alert signl4_list_teams signl4_list_categories
The AI acknowledges an alert, adds a note to its timeline, or closes it, on behalf of a SIGNL4 user you name.
Changes data · signl4_acknowledge_alert signl4_annotate_alert signl4_close_alert signl4_list_users
The login page asks for your SIGNL4 API key.
Create it in the SIGNL4 web portal under Integrations → API Keys. The key is used only to call the SIGNL4 API on your behalf; it is never shown to anyone.
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 SIGNL4 API key. 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.
Turn on the SIGNL4 connector, then ask in plain words. The AI picks the tools.
| Tool | Type | What it does |
|---|---|---|
signl4_list_teams | read | List teams List the SIGNL4 teams the API key can access: id, name, description, time zone and member ids. Team ids are needed to raise alerts and to look up categories and duties. GET /v3/teams. |
signl4_get_team | read | Get team One SIGNL4 team: name, description, time zone, member ids. GET /v3/teams/{teamId}. |
signl4_list_users | read | List users List the SIGNL4 users the key can access with name, e-mail, contact addresses, activation state and duty status per team (dutyMode, onDutyTime). User ids are needed to acknowledge/close/annotate alerts. GET /v3/users. |
signl4_get_user | read | Get user One SIGNL4 user: name, e-mail, contact addresses, time zone and duty status per team. GET /v3/users/{userId}. |
signl4_list_team_users | read | List users of teams List the users of the given teams (all accessible teams by default) with duty status. Teams that cannot be read are reported under `errors`. GET /v3/teams/users. |
signl4_list_categories | read | List alert categories List the alert categories of a team (name, color, keywords used to auto-classify alerts). The category name can be passed to signl4_raise_alert. GET /v3/categories/{teamId}. |
signl4_list_alerts | read | List alerts Search SIGNL4 alerts (signls), newest first, with status, severity, category and history (created, acknowledged, closed). Filter by team, status, creation time, text or external id. Up to 100 per page; pass the returned continuation_token to get the next page. POST /v3/signls/paged (a read). |
signl4_get_alert | read | Get alert Full detail of one alert: title, text, severity, category, status and delivery status, history (who acknowledged/closed it and when), parameters, attachments and escalations with per-user delivery. GET /v3/signls/{signlId}/details. |
signl4_get_alert_timeline | read | Get alert timeline The ordered timeline of an alert: creation, notifications, acknowledgements, annotations, escalations and remote actions. GET /v3/signls/{signlId}/timeline. |
signl4_get_alert_report | read | Get alert report Alert volume and response statistics per team over several time periods: acknowledged, closed and unhandled counts, overall and per category (optionally for one user). Teams that cannot be read are reported under `errors`. GET /v3/signls/report. |
signl4_raise_alert | write | Raise alert WRITE: raise a new alert in a SIGNL4 team. THIS NOTIFIES REAL PEOPLE: every team member currently on duty is paged (push, SMS and/or voice call according to their settings) and the alert escalates if nobody acknowledges it. Only use it when the user clearly asked to alert the team; never for tests unless they said so. Not idempotent: a second call pages the team again. Returns the new alert incl. its id. POST /v3/signls. |
signl4_acknowledge_alert | write | Acknowledge alert WRITE: acknowledge an alert on behalf of a SIGNL4 user (recorded in its history under that user). Stops escalation to further tiers for that alert. POST /v3/signls/{signlId}/acknowledge. |
signl4_close_alert | write | Close alert WRITE: close (resolve) an alert on behalf of a SIGNL4 user; it leaves the open list and stops all further notifications. POST /v3/signls/{signlId}/close. |
signl4_annotate_alert | write | Annotate alert WRITE: add a text note to an alert's timeline on behalf of a SIGNL4 user. The note is visible to the team in the app. It does not page anyone by itself. POST /v3/signls/{signlId}/annotate. |
signl4_list_duty_schedules | read | List duty schedules Planned on-call duty schedules (who is on duty when): start/end, team, user, tier, stand-in and shift info. Filter by team, user and time window. POST /v3/schedules (a read). |
signl4_get_duty_status | read | Get user duty status Whether a user is currently on or off duty in each of their teams (dutyMode, onDutyTime, tier). GET /v3/users/{userId}/dutyStatus. |
signl4_get_duty_summary | read | Get duty summary Duty assistant info per team: whether it is enabled and the last two (or all) duty periods. GET /v3/duties/summary. |
signl4_list_audit_logs | read | List audit logs Audit log of changes and events in the SIGNL4 subscription (who changed what, when). Filter by team, time window and message text; pass the returned continuation_token for the next page. GET /v3/audits. |
signl4_usage_status | Usage status (free-tier meter) Report the caller's current usage: the plan, calls used this month, the limit of the plan (the free monthly cap or the Pro fair use limit), remaining, and whether the limit is reached. Read-only; does not count against the meter. | |
signl4_request_feature | Request a missing feature Tell usefulapi that the user needs something the SIGNL4 tools cannot do yet (a missing tool, field or filter). Call it only when the user asks for something none of the tools can do, and tell the user that you send the request. Do not call it for errors or for normal requests. Do not include personal data, credentials or customer records. Stored with the product name and the client type (for example Claude or Cursor), without the user's account. At most 5 requests per day. Does not count against the meter. | |
signl4_upgrade | Upgrade to Pro (unlimited*) Get Pro: unlimited tool calls (fair use limit: 10,000 a month) on SIGNL4 (the free tier caps monthly usage). Plans: "monthly" — $9/month; "yearly" — $90/year (2 months free). Cancel any time: Pro then runs to the end of the paid period, so it also suits a one-time job. *A fair use limit applies. For heavy use (near Pro's limit): "plus" or "plus_yearly" — Pro+, $39/month or $390/year, unlimited tool calls (fair use limit: 100,000 a month); an existing Pro subscription changes to Pro+ in place (needs confirm: true; the price difference for the rest of the period is charged at once). Otherwise returns a short link to open in your browser (it opens Stripe Checkout); after payment the account upgrades automatically. Does not count against the meter. | |
signl4_cancel_subscription | Cancel the Pro subscription Cancel the caller's SIGNL4 Pro subscription at the end of the paid period (no refund for the current period; Pro continues until then, then the free tier applies). Requires confirm: true. Run signl4_upgrade later to undo the cancel before the period ends. Does not count against the meter. |
| Plan | Price | Limit |
|---|---|---|
| Free | $0 | 50 tool calls / month |
| Proper account | $9/mo · $90/yr | Unlimited* |
*Pro fair use limit: 10,000 tool calls a month on this server. For more, write to [email protected].
Pro covers this SIGNL4 server only. Subscribe with signl4_upgrade (it returns a Stripe Checkout link). Cancel any time with signl4_cancel_subscription: Pro continues to the end of the paid period, with no refund for the current period, and running signl4_upgrade before then undoes the cancel. Or write to [email protected].
Find alerts that are still open. See who is on duty now and later. Read what happened to an alert. Report alert volume and response per team. Raise an alert for a team. Acknowledge, annotate or close alerts. See what you can do for the details.
No. usefulapi is an independent service. It is not affiliated with or endorsed by SIGNL4. The server calls the SIGNL4 API with your own SIGNL4 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 SIGNL4 API key. See Before you connect for where to find it.
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 SIGNL4 API key. 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 SIGNL4 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 SIGNL4.
Yes, if you approve it. 4 of the 18 SIGNL4 tools can create or change data. The other 14 are marked read-only. Most MCP clients ask you to approve a tool call before it runs.
The Free plan gives 50 tool calls / month. Pro costs $9/mo or $90/yr, with unlimited tool calls (fair use limit: 10,000 tool calls a month), for this SIGNL4 server only. Cancel any time: Pro then runs to the end of the paid period. Run signl4_usage_status to see how many calls you used.
Ask the AI to run signl4_upgrade: it returns a Stripe Checkout link. To cancel, run signl4_cancel_subscription. Pro continues to the end of the paid period.
Tell the AI what you wanted to do. It can send the request with signl4_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.