Scheduled Digest Bot

A scheduled digest bot built with Next.js, Chat SDK, the AI SDK, Vercel Connect, and Vercel Workflow.

Vercel Cron calls /api/cron/digest, the route starts a durable workflow, and the workflow processes the configured channel in retryable steps: it gathers GitHub activity, turns it into a structured digest with the AI SDK, and posts a Chat SDK Card to Slack.

Vercel Cron ──► /api/cron/digest ──► Workflow
                                       ├─ fetchGitHubActivity  (Vercel Connect → GitHub REST + GraphQL)
                                       ├─ generateDigest       (AI SDK structured output)
                                       └─ postDigest           (Chat SDK Card → Slack)

Prerequisites

• Node.js 20+ and pnpm.
• A Vercel account with the project linked (vercel link). Vercel Connect and the local OIDC token both require a linked project.
• A Slack workspace where you can install a connector/bot.
• A GitHub account or organization to source issue activity from.
• A Redis instance for Chat SDK state and message de-duplication.

Quick start

# 1. Install dependencies
pnpm install

# 2. Link the project to Vercel (needed for Vercel Connect + OIDC)
pnpm dlx vercel link

# 3. Create your local env file and fill in the values (see table below)
cp .env.example .env.local

# 4. Pull Vercel-managed env + a fresh OIDC token for Connect
pnpm dlx vercel env pull

# 5. Run the dev server
pnpm dev

The app runs at http://localhost:3000, which renders an operator overview of the routes, schedule, and required environment.

Environment variables

Copy .env.example to .env.local and set the following. On Vercel, add the same variables under Project → Settings → Environment Variables.

Local development & Vercel Connect: CONNECTOR_SLACK/CONNECTOR_GITHUB issue tokens via Vercel Connect, which authenticates with a Vercel OIDC token. Run vercel env pull after linking (or use vercel dev) so the SDK has a valid token locally — vercel dev refreshes it automatically.

Run and test locally

Start the dev server:

pnpm dev

Trigger the cron route manually (the route fails closed if CRON_SECRET is unset or the header does not match):

curl -H "Authorization: Bearer $CRON_SECRET" \
  http://localhost:3000/api/cron/digest

Inspect workflow runs in the local Workflow dashboard:

pnpm exec workflow web

Configure Slack

1. Create a Slack connector in Vercel Connect and keep triggers enabled.

2. Register this project as a trigger destination:

   https://your-app.vercel.app/api/webhooks/slack

3. Grant bot scopes such as chat:write, channels:history, channels:read, groups:history, im:history, mpim:history, reactions:write, and users:read, then link the connector to this Vercel project and environment.

The Slack adapter reads CONNECTOR_SLACK, calls getToken() from @vercel/connect, and uses the returned short-lived token for Slack API calls. The Redis state adapter reads REDIS_URL.

Vercel Connect verifies Slack events before forwarding them, so lib/bot.ts delegates webhook verification to Connect. If you receive webhooks directly from Slack instead of through Connect, configure SLACK_SIGNING_SECRET and use the adapter's built-in Slack verification.

Configure Cron

vercel.json schedules the digest daily at 08:00 UTC:

{
  "crons": [
    {
      "path": "/api/cron/digest",
      "schedule": "0 8 * * *"
    }
  ]
}

Vercel Cron sends Authorization: Bearer $CRON_SECRET; the route fails closed when CRON_SECRET is unset or the header does not match.

Enroll channels

Set DIGEST_CHANNEL_ID to the Chat SDK channel ID where the digest should post:

DIGEST_CHANNEL_ID=slack:C123ABC

The template expands that channel ID into a digest input in lib/digest/enrollment.ts. Update that file to change the lookback window, details URL, tone, section limit, or included source areas.

Replace lib/digest/sources.ts to digest GitHub pull requests, Linear issues, support tickets, database rows, or another source.

Repository discovery

The digest uses CONNECTOR_GITHUB to fetch the repositories visible to the GitHub connector. It counts public and private repositories, counts open issues in connector-accessible repositories, fetches issues created inside the configured lookback window, and excludes pull requests.

To keep large installations predictable, the source fetches up to 1,000 active repositories for totals and limits detailed per-repository issue checks to the first 25 active repositories. Change the detail limit in lib/digest/sources.ts:

const MAX_REPOSITORIES_TO_DIGEST = 25;

The GitHub connector must be installed with access to the repositories you want included. Issue counts and recent issue details are fetched with batched GitHub GraphQL queries instead of the Search API, which avoids the much lower Search API rate limit and keeps totals scoped to repositories visible to the connector.

Workflow steps

The scheduled digest keeps source fetching, generation, and Slack delivery in separate Workflow steps:

• fetchGitHubActivity discovers repositories, counts open issues, and fetches recent issue details.
• generateDigest turns the structured activity payload into the digest schema.
• postDigest sends the Chat SDK Card to Slack.

Keeping these separate makes Workflow retries and run inspection clearer: a GitHub API failure retries only the GitHub step, while a Slack delivery failure retries only the posting step.

Project structure

Deploy

Push to a repository connected to Vercel, or run pnpm dlx vercel --prod. Set all required environment variables on the project, ensure the Slack and GitHub connectors are linked to the project/environment, and Vercel Cron will invoke the digest on the configured schedule.