Curated free-tier infrastructure stacks for AI agents — RAG, coding agents, data pipelines, and chatbots. $0/month to start.

AI Agent Builder’s Free Stack Guide

Curated free-tier infrastructure stacks for common AI agent patterns. Each service carries the same verdict our own vendor page gives it. The limits on this page were read from vendor pricing pages between 2026-07-31 and 2026-09-01.

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RAG Agent

Retrieval-augmented generation — ingest documents, embed them, and answer questions with citations.

Total: $0/month
$0 covers the 3 of 4 picks whose free tier our own badge still reads as active. It does not cover Supabase (at risk).
RoleServiceFree TierOur verdict
Vector DB Pinecone Starter Vector database — 2 GB storage, 2M write units/month, 1M read units/month, 5 indexes, 5M embedding tokens/month. Pinecone Assistant: 100… active
LLM API Groq Free Ultra-fast LLM inference on LPU hardware — free tier: 30 RPM, 100K-500K tokens/day depending on model. Supports Llama 4 Scout 17B, Llama… active
Compute Vercel Hobby Hobby plan with 100 GB/month Fast Data Transfer, 1M function invocations, 4 hrs Active CPU, 360 GB-hrs Provisioned Memory, 1M edge… active
Database & Storage Supabase Free The free tier includes unlimited API requests, 50,000 monthly active users, 500 MB database size, 5 GB egress, 1 GB file storage. Free… read 2026-09-03 at risk
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Autonomous Coding Agent

An agent that writes code, runs tests, and ships PRs — the foundation for AI-powered development workflows.

Total: $0/month
$0 covers the 3 of 4 picks whose free tier our own badge still reads as active. It does not cover OpenRouter (at risk).
RoleServiceFree TierOur verdict
LLM API OpenRouter Free Free tier includes 25+ free models, 4 free providers, 50 reqs/day rate limit, $25,000 of list price inference / month with no fees, 5% fee… read 2026-09-07 at risk
CI/CD GitHub Actions Free Free CI/CD for public repos (unlimited minutes). Private repos: 2,000 min/mo GitHub-hosted runners, 500 MB artifact storage, 10 GB… active
Monitoring Grafana Cloud Free Free tier with 10K metric series, 50 GB logs, 50 GB traces, 14-day retention, 3 users active
Auth Clerk Hobby Drop-in auth with 50K monthly retained users free, unlimited apps active
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Data Pipeline Agent

Orchestrate data ingestion, transformation, and loading — ETL pipelines that run themselves.

Total: $0/month
$0 covers all 4 picks: our own badge reads every one of their free tiers as active.
RoleServiceFree TierOur verdict
Database Neon Free Serverless Postgres with branching — free tier includes 100 CU-hours/month per project, 0.5 GB storage per project, up to 100 projects, 10… active
Queue & Cache Upstash Free Serverless Redis — 500K commands/month (256MB data). Vector: 10K vectors free. QStash: 1,000 messages/day free active
Object Storage Cloudflare R2 Free Object storage with zero egress fees — 10 GB storage, 1M writes, 10M reads/month free active
Monitoring BetterStack Free 10 uptime monitors, 3 GB logs (3-day retention), 100K exceptions/mo, 5K session replays, 30 GB metrics, 1 status page, 1 responder active
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Chat / Customer Agent

Customer-facing conversational agent with auth, analytics, and fast inference.

Total: $0/month
$0 covers the 3 of 4 picks whose free tier our own badge still reads as active. It does not cover Supabase (at risk).
RoleServiceFree TierOur verdict
LLM API Groq Free Ultra-fast LLM inference on LPU hardware — free tier: 30 RPM, 100K-500K tokens/day depending on model. Supports Llama 4 Scout 17B, Llama… active
Database Supabase Free The free tier includes unlimited API requests, 50,000 monthly active users, 500 MB database size, 5 GB egress, 1 GB file storage. Free… read 2026-09-03 at risk
Auth Auth0 Free Identity platform — 25K MAU (B2C), unlimited logins, social + database connections, Universal Login, 1 Enterprise Connection, 5… active
Analytics PostHog Free Product analytics — 1M events/month, 5K session replays, 1M feature flag requests, 100K error events, A/B testing. No credit card required active

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