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

Published 2026-03-19 · Not yet reviewed

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 2026-09-22.

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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 Groq (at risk).
RoleServiceFree TierOur verdict
Vector DB Pinecone Free Vector database. The Starter plan is free: up to 2 GB storage, 2M write units and 1M read units a month, 1 GB of egress a month (reads that… active
LLM API Groq Free Fast LLM inference on Groq's LPU hardware. Free plan: gpt-oss-120b, gpt-oss-20b and Qwen3.8 27B, each at 30 requests a minute, 1,000… at risk
Compute Vercel Hobby Hobby plan, $0 a month, for non-commercial personal use only. Includes 100 GB Fast Data Transfer, 1M Edge Requests, 1M Function… active
Database & Storage Supabase Free Postgres development platform: database, Auth, Storage, Realtime and Edge Functions. The Free plan is $0: unlimited API requests, 50,000… active
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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 all 4 picks: our own badge reads every one of their free tiers as active.
RoleServiceFree TierOur verdict
LLM API OpenRouter Free AI model router. Free plan: 25+ free models, 4 free providers, 50 requests a day, no BYOK. Free models are capped at 20 requests a minute… active
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 includes access to all Grafana Cloud services with limited usage, 14-day retention, and community support. 10k metric series, 50… 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 Free for personal projects $0 per month Start for free 10 monitors & heartbeats, 1 status page Slack & e-mail alerts 100,000 exceptions per… read 2026-09-02 active
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Chat / Customer Agent

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

Total: $0/month
$0 covers the 2 of 4 picks whose free tier our own badge still reads as active. It does not cover Groq (at risk), PostHog (unrated — change refused).
RoleServiceFree TierOur verdict
LLM API Groq Free Fast LLM inference on Groq's LPU hardware. Free plan: gpt-oss-120b, gpt-oss-20b and Qwen3.8 27B, each at 30 requests a minute, 1,000… at risk
Database Supabase Free Postgres development platform: database, Auth, Storage, Realtime and Edge Functions. The Free plan is $0: unlimited API requests, 50,000… active
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 unrated — change refused

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