X (Twitter) AI Agent - Autonomous Posting & Engagement

Autonomous X account. Researches AI/dev topics daily, writes and schedules posts, and replies to mentions in real time — all driven by xAI Grok via the Vercel AI SDK.

How it works

Three independent loops:

Posting pipeline — triggered once daily by cron:

GET /cron/daily → researcher → writer → scheduler → Neon → cron-job.org → POST /cron/execute-post → X API

1. Researcher (grok-4-latest, Responses API) — webSearch + xSearch, up to 10 steps. Produces a brief with 5–8 AI/infra content angles from the last 24 hours.
2. Writer (grok-4-latest, Chat Completions) — turns the brief into 4–6 posts. Structured output via Zod.
3. Scheduler (grok-4-1-fast-non-reasoning) — assigns times to named slots (morning/lunch/afternoon/evening/night), minimum 90 minutes apart. Structured output.

Posts land in Neon as pending. cron-job.org polls /cron/execute-post every 30 minutes to publish what's due.

Outbound engagement loop — triggered on a schedule:

POST /cron/outbound-engagement → getHomeFeed(100) → signal filter → outbound agent → like/retweet/follow → X API

1. Fetches up to 100 tweets from the home timeline (accounts the user follows).
2. Deduplicates by tweet ID; filters by signal threshold (≥10 likes, 100–500K author followers).
3. Queries outbound_engagement_log to skip already-acted tweets and authors on a 6-hour follow cooldown.
4. Outbound agent (grok-4-latest, Chat Completions) — scores each candidate and returns like/retweet/follow decisions. Per-run caps: 10 likes, 3 retweets, 3 follows.
5. Executes actions via X API; logs all outcomes for dedup and cooldown enforcement.

Inbound engagement loop — real-time via X Account Activity API:

X webhook → POST /webhooks/x → inbound engagement agent → replyToTweet → X API

On every mention or reply, the inbound engagement agent (grok-4-latest) reads full thread context and returns one of:

• skip — spam, low-effort, or nothing to add
• reply/close — self-contained reply that ends the exchange
• reply/probe — reply ending with one pointed, technical question

Claims are written to engagement_log before the LLM call. Duplicate webhook deliveries are no-ops.

Stack

• Vercel AI SDK — generateText (researcher) / generateObject (writer, scheduler, engagement)
• xAI Grok — Responses API and Chat Completions (not interchangeable)
• Bun — runtime, package manager, test runner
• Hono — HTTP server on port 3010
• Neon + Drizzle ORM — Postgres (scheduled posts + engagement log)
• X API v2 (XDK) — OAuth1 for posting; Bearer token for thread hydration
• Docker — oven/bun:1-alpine
• Amazon ECR + EC2 — t3.micro, us-east-2, behind Nginx
• GitHub Actions — build → ECR push → SSH deploy on every main push

Local development

bun install
cp .env.example .env
bunx drizzle-kit push
bun run dev

bun run test:researcher
bun run test:writer
bun run test:scheduler
bun run test:agents          # full pipeline

bun run test:cron:daily
bun run test:cron:execute-post

Environment variables

Variable	Description
XAI_API_KEY	xAI API key
X_API_KEY	OAuth1 API key
X_API_SECRET	OAuth1 API secret (also used for webhook HMAC)
X_ACCESS_TOKEN	OAuth1 access token
X_ACCESS_TOKEN_SECRET	OAuth1 access token secret
X_USER_ID	Numeric user ID — required for like, retweet, follow, and webhook self-event filtering
X_BEARER_TOKEN	App-only bearer token (thread context hydration)
X_HANDLE	Agent's X handle without @ — used to enforce the 1:1 thread depth cap
DATABASE_URL	Neon Postgres connection string
CRON_SECRET	Required. Shared secret for /cron/* routes

HTTP API

Method	Path	Description
GET	/	Health check
GET	/cron/daily	Trigger posting pipeline (async, returns 202)
POST	/cron/execute-post	Publish due posts; no body = scan all, { postId } = single
POST	/cron/outbound-engagement	Trigger outbound engagement run (async, returns 202)
GET	/webhooks/x	X CRC handshake
POST	/webhooks/x	Incoming mention/reply events (HMAC-verified)

Cron routes require the x-cron-secret header. Query-param auth is not supported (avoids leaking secrets to access logs).

Deployment

Every push to main builds a linux/amd64 image, pushes to ECR, and SSH-deploys to EC2 via docker compose pull && up -d.

aws ecr get-login-password --region us-east-2 | \
  docker login --username AWS --password-stdin <ACCOUNT_ID>.dkr.ecr.us-east-2.amazonaws.com
docker buildx build --platform linux/amd64 \
  -t <ACCOUNT_ID>.dkr.ecr.us-east-2.amazonaws.com/twitter/agent:latest --push .

# On EC2
cd ~/twitter-agent && docker compose pull && docker compose up -d

Register the webhook (once after deploy):

bun scripts/subscribe-webhook.ts

Cron schedule (cron-job.org)

Job	Endpoint	Schedule
Daily pipeline	GET /cron/daily	Once daily
Publish due posts	POST /cron/execute-post	Every 30 minutes
Outbound engagement	POST /cron/outbound-engagement	Configurable (e.g. every 2h)