feat: support Slack webhook URL as alternative to token+channel for all monitors

.env.sample

@@ -1,11 +1,14 @@
 NODE_ENV=
 
+RETRYABLE_MONITORING_SLACK_WEBHOOK_URL=
 RETRYABLE_MONITORING_SLACK_TOKEN=
 RETRYABLE_MONITORING_SLACK_CHANNEL=
 RETRYABLE_MONITORING_PRIVATE_KEY=
 
+BATCH_POSTER_MONITORING_SLACK_WEBHOOK_URL=
 BATCH_POSTER_MONITORING_SLACK_TOKEN=
 BATCH_POSTER_MONITORING_SLACK_CHANNEL=
 
+ASSERTION_MONITORING_SLACK_WEBHOOK_URL=
 ASSERTION_MONITORING_SLACK_TOKEN=
 ASSERTION_MONITORING_SLACK_CHANNEL=

README.md

@@ -70,14 +70,17 @@ cp config.example.json config.json
 cp .env.sample .env
 ```
 
-2. Set up Slack alerts in `.env` (optional):
+2. Set up Slack alerts in `.env` (optional). For each monitor, set either a webhook URL (preferred, scoped to a single channel) or a token + channel; the webhook takes precedence if both are set:
 
 ```bash
 NODE_ENV=CI
+RETRYABLE_MONITORING_SLACK_WEBHOOK_URL=your-slack-webhook-url
 RETRYABLE_MONITORING_SLACK_TOKEN=your-slack-token
 RETRYABLE_MONITORING_SLACK_CHANNEL=your-slack-channel
+BATCH_POSTER_MONITORING_SLACK_WEBHOOK_URL=your-slack-webhook-url
 BATCH_POSTER_MONITORING_SLACK_TOKEN=your-slack-token
 BATCH_POSTER_MONITORING_SLACK_CHANNEL=your-slack-channel
+ASSERTION_MONITORING_SLACK_WEBHOOK_URL=your-slack-webhook-url
 ASSERTION_MONITORING_SLACK_TOKEN=your-slack-token
 ASSERTION_MONITORING_SLACK_CHANNEL=your-slack-channel
 ```

packages/assertion-monitor/README.md

@@ -25,6 +25,7 @@ Examples:
   yarn assertion-monitor --configPath=custom.json   Use custom config file
 
 Environment Variables:
+  ASSERTION_MONITORING_SLACK_WEBHOOK_URL  Slack webhook URL for alerts (preferred over token+channel)
   ASSERTION_MONITORING_SLACK_TOKEN    Slack API token for alerts
   ASSERTION_MONITORING_SLACK_CHANNEL  Slack channel for alerts
 ```

packages/assertion-monitor/reportAssertionMonitorAlertToSlack.ts

@@ -1,6 +1,7 @@
 import { createSlackPoster } from 'utils'
 
 export const reportAssertionMonitorErrorToSlack = createSlackPoster({
+  webhookUrlEnvVar: 'ASSERTION_MONITORING_SLACK_WEBHOOK_URL',
   tokenEnvVar: 'ASSERTION_MONITORING_SLACK_TOKEN',
   channelEnvVar: 'ASSERTION_MONITORING_SLACK_CHANNEL',
 })

packages/batch-poster-monitor/README.md

@@ -25,6 +25,7 @@ Examples:
   yarn batch-poster-monitor --configPath=custom.json   Use custom config file
 
 Environment Variables:
+  BATCH_POSTER_MONITORING_SLACK_WEBHOOK_URL  Slack webhook URL for alerts (preferred over token+channel)
   BATCH_POSTER_MONITORING_SLACK_TOKEN    Slack API token for alerts
   BATCH_POSTER_MONITORING_SLACK_CHANNEL  Slack channel for alerts
 ```

packages/batch-poster-monitor/reportBatchPosterAlertToSlack.ts

@@ -1,6 +1,7 @@
 import { createSlackPoster } from 'utils'
 
 export const reportBatchPosterErrorToSlack = createSlackPoster({
+  webhookUrlEnvVar: 'BATCH_POSTER_MONITORING_SLACK_WEBHOOK_URL',
   tokenEnvVar: 'BATCH_POSTER_MONITORING_SLACK_TOKEN',
   channelEnvVar: 'BATCH_POSTER_MONITORING_SLACK_CHANNEL',
 })

packages/retryable-monitor/README.md

@@ -29,6 +29,7 @@ Examples:
   yarn retryable-monitor --enableAlerting --writeToNotion           Enables Slack alerts and syncs retryable data to Notion
 
 Environment Variables:
+  RETRYABLE_MONITORING_SLACK_WEBHOOK_URL  Slack webhook URL for alerts (preferred over token+channel)
   RETRYABLE_MONITORING_SLACK_TOKEN    Slack API token for alerts
   RETRYABLE_MONITORING_SLACK_CHANNEL  Slack channel for alerts
   RETRYABLE_MONITORING_NOTION_TOKEN   Notion integration token

packages/retryable-monitor/handlers/slack/postSlackMessage.ts

@@ -1,6 +1,7 @@
 import { createSlackPoster } from 'utils'
 
 export const postSlackMessage = createSlackPoster({
+  webhookUrlEnvVar: 'RETRYABLE_MONITORING_SLACK_WEBHOOK_URL',
   tokenEnvVar: 'RETRYABLE_MONITORING_SLACK_TOKEN',
   channelEnvVar: 'RETRYABLE_MONITORING_SLACK_CHANNEL',
 })

packages/utils/__test__/createSlackPoster.test.ts

@@ -5,7 +5,12 @@ vi.mock('../postSlackMessage', () => ({
   postSlackMessage: vi.fn().mockResolvedValue({ ok: true }),
 }))
 
+vi.mock('../postSlackMessageViaWebhook', () => ({
+  postSlackMessageViaWebhook: vi.fn().mockResolvedValue({ ok: true }),
+}))
+
 import { postSlackMessage } from '../postSlackMessage'
+import { postSlackMessageViaWebhook } from '../postSlackMessageViaWebhook'
 
 describe('createSlackPoster', () => {
   const originalEnv = process.env
@@ -15,6 +20,7 @@ describe('createSlackPoster', () => {
     process.env = { ...originalEnv }
     delete process.env.TEST_SLACK_TOKEN
     delete process.env.TEST_SLACK_CHANNEL
+    delete process.env.TEST_SLACK_WEBHOOK_URL
     delete process.env.NODE_ENV
   })
 
@@ -40,6 +46,84 @@ describe('createSlackPoster', () => {
     expect(() => poster({ message: 'test' })).toThrow('Slack channel is required.')
   })
 
+  test('throws with either-or message when webhook is supported but nothing is configured', () => {
+    const poster = createSlackPoster({
+      tokenEnvVar: 'TEST_SLACK_TOKEN',
+      channelEnvVar: 'TEST_SLACK_CHANNEL',
+      webhookUrlEnvVar: 'TEST_SLACK_WEBHOOK_URL',
+    })
+    expect(() => poster({ message: 'test' })).toThrow(
+      'Slack configuration is required: set TEST_SLACK_WEBHOOK_URL (preferred) or both TEST_SLACK_TOKEN and TEST_SLACK_CHANNEL.'
+    )
+  })
+
+  test('throws with either-or message when webhook is supported and only token is set', () => {
+    process.env.TEST_SLACK_TOKEN = 'token'
+    const poster = createSlackPoster({
+      tokenEnvVar: 'TEST_SLACK_TOKEN',
+      channelEnvVar: 'TEST_SLACK_CHANNEL',
+      webhookUrlEnvVar: 'TEST_SLACK_WEBHOOK_URL',
+    })
+    expect(() => poster({ message: 'test' })).toThrow(
+      'Slack configuration is required: set TEST_SLACK_WEBHOOK_URL (preferred) or both TEST_SLACK_TOKEN and TEST_SLACK_CHANNEL.'
+    )
+  })
+
+  test('posts via webhook when only webhook is configured', () => {
+    process.env.TEST_SLACK_WEBHOOK_URL = 'https://hooks.slack.com/services/x'
+    const poster = createSlackPoster({
+      tokenEnvVar: 'TEST_SLACK_TOKEN',
+      channelEnvVar: 'TEST_SLACK_CHANNEL',
+      webhookUrlEnvVar: 'TEST_SLACK_WEBHOOK_URL',
+    })
+
+    poster({ message: 'Hello' })
+
+    expect(postSlackMessageViaWebhook).toHaveBeenCalledWith({
+      webhookUrl: 'https://hooks.slack.com/services/x',
+      message: 'Hello',
+    })
+    expect(postSlackMessage).not.toHaveBeenCalled()
+  })
+
+  test('webhook takes precedence when both webhook and token+channel are configured', () => {
+    process.env.TEST_SLACK_WEBHOOK_URL = 'https://hooks.slack.com/services/x'
+    process.env.TEST_SLACK_TOKEN = 'token'
+    process.env.TEST_SLACK_CHANNEL = 'channel'
+    const poster = createSlackPoster({
+      tokenEnvVar: 'TEST_SLACK_TOKEN',
+      channelEnvVar: 'TEST_SLACK_CHANNEL',
+      webhookUrlEnvVar: 'TEST_SLACK_WEBHOOK_URL',
+    })
+
+    poster({ message: 'Hello' })
+
+    expect(postSlackMessageViaWebhook).toHaveBeenCalledWith({
+      webhookUrl: 'https://hooks.slack.com/services/x',
+      message: 'Hello',
+    })
+    expect(postSlackMessage).not.toHaveBeenCalled()
+  })
+
+  test('falls back to token+channel when webhook is supported but not set', () => {
+    process.env.TEST_SLACK_TOKEN = 'token'
+    process.env.TEST_SLACK_CHANNEL = 'channel'
+    const poster = createSlackPoster({
+      tokenEnvVar: 'TEST_SLACK_TOKEN',
+      channelEnvVar: 'TEST_SLACK_CHANNEL',
+      webhookUrlEnvVar: 'TEST_SLACK_WEBHOOK_URL',
+    })
+
+    poster({ message: 'Hello' })
+
+    expect(postSlackMessage).toHaveBeenCalledWith({
+      slackToken: 'token',
+      slackChannel: 'channel',
+      message: 'Hello',
+    })
+    expect(postSlackMessageViaWebhook).not.toHaveBeenCalled()
+  })
+
   test('skips posting in DEV mode', () => {
     process.env.TEST_SLACK_TOKEN = 'token'
     process.env.TEST_SLACK_CHANNEL = 'channel'
@@ -54,6 +138,20 @@ describe('createSlackPoster', () => {
     expect(postSlackMessage).not.toHaveBeenCalled()
   })
 
+  test('skips posting in DEV mode with webhook config', () => {
+    process.env.TEST_SLACK_WEBHOOK_URL = 'https://hooks.slack.com/services/x'
+    process.env.NODE_ENV = 'DEV'
+
+    const poster = createSlackPoster({
+      tokenEnvVar: 'TEST_SLACK_TOKEN',
+      channelEnvVar: 'TEST_SLACK_CHANNEL',
+      webhookUrlEnvVar: 'TEST_SLACK_WEBHOOK_URL',
+    })
+
+    expect(poster({ message: 'test' })).toBeUndefined()
+    expect(postSlackMessageViaWebhook).not.toHaveBeenCalled()
+  })
+
   test('skips posting in CI mode when message is "success"', () => {
     process.env.TEST_SLACK_TOKEN = 'token'
     process.env.TEST_SLACK_CHANNEL = 'channel'
@@ -68,6 +166,20 @@ describe('createSlackPoster', () => {
     expect(postSlackMessage).not.toHaveBeenCalled()
   })
 
+  test('skips posting in CI mode when message is "success" with webhook config', () => {
+    process.env.TEST_SLACK_WEBHOOK_URL = 'https://hooks.slack.com/services/x'
+    process.env.NODE_ENV = 'CI'
+
+    const poster = createSlackPoster({
+      tokenEnvVar: 'TEST_SLACK_TOKEN',
+      channelEnvVar: 'TEST_SLACK_CHANNEL',
+      webhookUrlEnvVar: 'TEST_SLACK_WEBHOOK_URL',
+    })
+
+    expect(poster({ message: 'success' })).toBeUndefined()
+    expect(postSlackMessageViaWebhook).not.toHaveBeenCalled()
+  })
+
   test('posts in CI mode when message is not "success"', () => {
     process.env.TEST_SLACK_TOKEN = 'token'
     process.env.TEST_SLACK_CHANNEL = 'channel'

packages/utils/createSlackPoster.ts

@@ -1,25 +1,45 @@
 import { postSlackMessage } from './postSlackMessage'
+import { postSlackMessageViaWebhook } from './postSlackMessageViaWebhook'
 
 export const createSlackPoster = ({
   tokenEnvVar,
   channelEnvVar,
+  webhookUrlEnvVar,
 }: {
   tokenEnvVar: string
   channelEnvVar: string
+  webhookUrlEnvVar?: string
 }) => {
   return ({ message }: { message: string }) => {
+    const slackWebhookUrl = webhookUrlEnvVar
+      ? process.env[webhookUrlEnvVar]
+      : undefined
     const slackToken = process.env[tokenEnvVar]
     const slackChannel = process.env[channelEnvVar]
 
-    if (!slackToken) throw new Error('Slack token is required.')
-    if (!slackChannel) throw new Error('Slack channel is required.')
+    if (!slackWebhookUrl && !(slackToken && slackChannel)) {
+      if (webhookUrlEnvVar) {
+        throw new Error(
+          `Slack configuration is required: set ${webhookUrlEnvVar} (preferred) or both ${tokenEnvVar} and ${channelEnvVar}.`
+        )
+      }
+      if (!slackToken) throw new Error('Slack token is required.')
+      throw new Error('Slack channel is required.')
+    }
 
     if (process.env.NODE_ENV === 'DEV') return
     if (process.env.NODE_ENV === 'CI' && message === 'success') return
 
+    if (slackWebhookUrl) {
+      return postSlackMessageViaWebhook({
+        webhookUrl: slackWebhookUrl,
+        message,
+      })
+    }
+
     return postSlackMessage({
-      slackToken,
-      slackChannel,
+      slackToken: slackToken as string,
+      slackChannel: slackChannel as string,
       message,
     })
   }

packages/utils/index.ts

@@ -2,6 +2,7 @@ export * from './types'
 export * from './config'
 export { getExplorerUrlPrefixes } from './getExplorerUrlPrefixes'
 export { postSlackMessage } from './postSlackMessage'
+export { postSlackMessageViaWebhook } from './postSlackMessageViaWebhook'
 export { createSlackPoster } from './createSlackPoster'
 export { parseAmount } from './amountUtils'
 export { resolveRollupAddress } from './resolveRollupAddress'

packages/utils/postSlackMessageViaWebhook.ts

@@ -0,0 +1,35 @@
+import { sanitizeSlackMessage } from './sanitizeSlackMessage'
+import { formatGitHubCIInfo } from './githubCIUtils'
+
+export const postSlackMessageViaWebhook = async ({
+  webhookUrl,
+  message,
+}: {
+  webhookUrl: string
+  message: string
+}) => {
+  // Append GitHub CI run information if available
+  const ciInfo = formatGitHubCIInfo()
+  const messageWithCIInfo = ciInfo ? `${message}\n\n${ciInfo}` : message
+
+  console.log(`>>> Posting message to Slack (webhook) -> ${messageWithCIInfo}`)
+
+  const response = await fetch(webhookUrl, {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify({
+      text: sanitizeSlackMessage(messageWithCIInfo),
+      unfurl_links: false,
+    }),
+  })
+
+  if (!response.ok) {
+    throw new Error(
+      `Failed to post Slack message via webhook: ${
+        response.status
+      } ${await response.text()}`
+    )
+  }
+
+  return response
+}