Webhook Tool

Reliable outbound notifications to Slack, Discord, Telegram, IFTTT, and more.

Overview

The webhook toolset delivers a notification to a destination you configure. The agent supplies only the message text: it never sees or chooses the URL, because a webhook URL is itself a credential (Slack and Mattermost embed a secret path, Discord a token, IFTTT a key, Telegram a bot token).

This is not a general HTTP client — that is the api toolset. The webhook toolset owns delivery:

• At-least-once delivery. Transient failures (429, 5xx, network errors) are retried with exponential backoff, honouring the server's Retry-After. A 4xx is permanent and fails immediately without wasting retries.
• Non-blocking. The call returns as soon as the notification is queued, so a slow or retrying endpoint never stalls the agent's turn. The agent is messaged back only if delivery ultimately fails.
• Storm protection. An identical message to the same destination inside a short window is suppressed, and notifications are rate limited, so a looping agent cannot flood a channel.
• Provider-shaped payloads. Each service's wire format is applied for you.

Configuration

The destination lives in webhook_config. Use ${env.VAR} for anything secret — values are expanded at call time and never stored in the config file.

toolsets:
  - type: webhook
    webhook_config:
      provider: slack
      url: ${env.SLACK_WEBHOOK_URL}

timeout on the toolset (seconds) overrides the per-request HTTP timeout.

Providers

Aliases are accepted: msteams/microsoft_teams → teams, google_chat/gchat → googlechat, rocket.chat → rocketchat.

Per-service examples

# Slack / Mattermost / Rocket.Chat — the URL is the credential
toolsets:
  - type: webhook
    webhook_config:
      provider: slack
      url: ${env.SLACK_WEBHOOK_URL}

# Discord — the token is part of the webhook URL
toolsets:
  - type: webhook
    webhook_config:
      provider: discord
      url: ${env.DISCORD_WEBHOOK_URL}

# Telegram — bot token in the URL, chat_id selects the destination chat
toolsets:
  - type: webhook
    webhook_config:
      provider: telegram
      url: https://api.telegram.org/bot${env.TELEGRAM_BOT_TOKEN}/sendMessage
      chat_id: "123456789"

# IFTTT — the key is part of the trigger URL
toolsets:
  - type: webhook
    webhook_config:
      provider: ifttt
      url: https://maker.ifttt.com/trigger/build_failed/with/key/${env.IFTTT_KEY}

# Generic endpoint authenticating with a bearer token
toolsets:
  - type: webhook
    webhook_config:
      provider: generic
      url: https://alerts.example.com/notify
      headers:
        Authorization: Bearer ${env.ALERTS_TOKEN}

send_webhook

Returns immediately once queued. On success nothing further happens; if delivery ultimately fails, the agent receives a message saying so.

Example

agents:
  root:
    model: openai/gpt-5-mini
    instruction: If a check fails, notify the team with send_webhook.
    toolsets:
      - type: webhook
        webhook_config:
          provider: slack
          url: ${env.SLACK_WEBHOOK_URL}

Note

Requests to non-public addresses are refused (the SSRF-safe HTTP client), and the configured URL is never echoed back to the model or into error messages.