SIGNL4 MCP server

Read SIGNL4 alerts, teams, users and duty schedules; raise, acknowledge, close and annotate alerts. Hosted by usefulapi: connect it to Claude, ChatGPT, Cursor or any MCP client.

Connect SIGNL450 free tool calls a month

What can I ask?

Turn on the SIGNL4 connector, then ask in plain words. The AI picks the tools.

Which alerts are still open and unacknowledged right now?
Who is on duty in our team right now and who is off?
How many alerts did each team get over the last weeks?
Show the timeline of our most recent alert, including who responded.

What you can do with SIGNL4 in Claude and ChatGPT

For on-call and operations teams who page their staff with SIGNL4.

Find alerts that are still open

The AI searches alerts by team, status, creation time, text or external id, and opens one for its status, severity and history.

See who is on duty now and later

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.

Read what happened to an alert

The AI reads the ordered timeline of an alert: notifications, acknowledgements, annotations and escalations, and who responded.

Report alert volume and response per team

The AI reads acknowledged, closed and unhandled alert counts per team over several periods, overall and per category.

Raise an alert for a team

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

Acknowledge, annotate or close alerts

The AI acknowledges an alert, adds a note to its timeline, or closes it, on behalf of a SIGNL4 user you name.

Changes data

How do I connect SIGNL4?

Before you connect

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.

Claude claude.ai · Desktop

Open Customize → Connectors, then click + Add → Add custom connector.
Enter the name SIGNL4 and this URL, then click Add:
https://signl4.usefulapi.io/mcp
Claude opens the login page: enter your SIGNL4 API key.
In a chat, click + → Connectors and turn on SIGNL4.

Team and Enterprise: an Owner adds the connector for the organization first.

ChatGPT chatgpt.com

Open Plugins, click +, then Add custom MCP server.
Enter the name SIGNL4 and this URL, choose OAuth as the authentication, confirm the warning and create it:
https://signl4.usefulapi.io/mcp
ChatGPT opens the login page: enter your SIGNL4 API key.
In Plugins, install SIGNL4, then choose it in a chat.

No Add custom MCP server option? It depends on your account or workspace settings: see OpenAI's guide.

Claude Code

Run this command, then run /mcp in Claude Code to log in:

claude mcp add --transport http signl4 https://signl4.usefulapi.io/mcp

Cursor

Add to Cursor or add this to ~/.cursor/mcp.json:

{
  "mcpServers": {
    "signl4": {
      "url": "https://signl4.usefulapi.io/mcp"
    }
  }
}

VS Code

Add to VS Code or add this to .vscode/mcp.json:

{
  "servers": {
    "signl4": {
      "type": "http",
      "url": "https://signl4.usefulapi.io/mcp"
    }
  }
}

Codex

Run these commands. The second one opens the login page:

codex mcp add signl4 --url https://signl4.usefulapi.io/mcp

codex mcp login signl4

Other clients

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.

https://signl4.usefulapi.io/mcp

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.

Pricing

Plan	Price	Limit
Free	$0	50 tool calls / month
Proper account	$9/mo · $90/yr	10,000 tool calls / month
Pro+per account	$39/mo · $390/yr	100,000 tool calls / month

Each paid plan covers this SIGNL4 server only. Ask your AI to run signl4_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 signl4_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 signl4_upgrade before then undoes the cancel. Or write to support@usefulapi.io.

Tools 22

Show all 22 tools (the AI picks them for you)

Read only · 14

List teamssignl4_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 teamsignl4_get_team
One SIGNL4 team: name, description, time zone, member ids.
List userssignl4_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 usersignl4_get_user
One SIGNL4 user: name, e-mail, contact addresses, time zone and duty status per team.
List users of teamssignl4_list_team_users
List the users of the given teams (all accessible teams by default) with duty status. Teams that cannot be read are reported under `errors`.
List alert categoriessignl4_list_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.
List alertssignl4_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).
Get alertsignl4_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 alert timelinesignl4_get_alert_timeline
The ordered timeline of an alert: creation, notifications, acknowledgements, annotations, escalations and remote actions.
Get alert reportsignl4_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`.
List duty schedulessignl4_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).
Get user duty statussignl4_get_duty_status
Whether a user is currently on or off duty in each of their teams (dutyMode, onDutyTime, tier).
Get duty summarysignl4_get_duty_summary
Duty assistant info per team: whether it is enabled and the last two (or all) duty periods.
List audit logssignl4_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.

Changes data · 4

Raise alertsignl4_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.
Acknowledge alertsignl4_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.
Close alertsignl4_close_alert
WRITE: close (resolve) an alert on behalf of a SIGNL4 user; it leaves the open list and stops all further notifications.
Annotate alertsignl4_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.

Your usefulapi plan · 4

Usage status (free-tier meter)signl4_usage_status
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.
Request a missing featuresignl4_request_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.
Upgrade to Pro or Pro+signl4_upgrade
Get a paid plan for SIGNL4 (the free tier caps monthly usage). Pro: 10,000 tool calls a month, for normal use — plan "monthly" ($9/month) or "yearly" ($90/year, 2 months free). Pro+: 100,000 tool calls a month, for automations and heavy use — plan "plus" ($39/month) or "plus_yearly" ($390/year). Without a plan it returns both Pro and Pro+, each with a payment link, for the user to choose; with a plan, one link. An existing Pro subscription changes to Pro+ in place: call without confirm first, as the reply states the exact charge for this account (the price difference for the rest of the period, or in a free Pro trial the full Pro+ price, as the trial ends); then call with confirm: true. Cancel any time: the plan then runs to the end of the paid period, so it also suits a one-time job. A link opens Stripe Checkout in the browser; after payment the account upgrades automatically. Does not count against the meter.
Cancel the Pro subscriptionsignl4_cancel_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.

FAQ

What can I do with SIGNL4 in Claude or ChatGPT?

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.

Is this an official SIGNL4 product?

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.

Can I connect SIGNL4 to Claude or ChatGPT?

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.

What do I need to connect?

The login page asks for your SIGNL4 API key. See Before you connect for where to find it.

Do I put my SIGNL4 key or an Authorization header in the client config?

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.

How do you keep my SIGNL4 credentials?

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.

Can the AI change my SIGNL4 data?

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.

What does it cost?

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 SIGNL4 server only. Cancel any time: your paid plan then runs to the end of the paid period. Run signl4_usage_status to see how many calls you used.

How do I subscribe or cancel?

Ask the AI to run signl4_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 signl4_cancel_subscription. Your paid plan continues to the end of the paid period.

What if a SIGNL4 tool that I need is missing?

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.

Which AI clients can I use?

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.

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