Agents — small scale stack.
For each requirement below, pick the option that fits your build — recommended first, then free and cheaper alternatives — or skip what your project doesn't need. Tap the info icon next to any requirement to see why it matters.
LLM Inference API / Foundation Model Access
Powers AI features — model access, embeddings, and inference. Costs scale with usage, so watch the meter.Pricing & free-tier limitsOpenAI: Free $5 credit; $2.50-$5/1M input, $10-$15/1M output (4o). Anthropic: $3/1M in $15/1M out (Sonnet 3.5). Groq: Free 100 req/min 14.4k/day, then payg $0.59/1M. Together: $0.20/1M tokens. Overage: pure payg, no min.
Agent Orchestration Framework
A piece of your stack you may or may not need, depending on scope. Pick the option that fits — or skip it if your project doesn’t require this capability yet.Pricing & free-tier limitsLangGraph OSS free unlimited; Cloud Free 5k runs/mo, $39/mo Dev 10k runs $0.01/run overage, Pro $399/mo 100k runs. CrewAI OSS free; Cloud $29/mo 1k runs $0.03/run overage. AutoGen free.
LLM API Gateway (Multi-model proxy)
Controls and protects your APIs — quotas, abuse prevention, and firewalls. Important once you have real traffic or many clients.Pricing & free-tier limitsLiteLLM OSS free unlimited; Cloudflare AI Gateway Free 1M req/mo cached logging free. Portkey Free 10k req/mo, $100/mo 100k req, $0.001/1k overage. Helicone Free 10k logs/mo then $20/mo. Caching saves 30-50% LLM cost.
Memory / Vector Database for Agent Memory
Persistent storage for your app’s data — users, products, orders. The single most important architectural decision for most projects.Pricing & free-tier limitsPinecone Free 100k vectors 1 index; Starter $70/mo supports 1M vectors $0.33/GB storage + $0.33/1M reads. Qdrant Free 1GB RAM cluster (5M vectors @ 768d), $25/mo 2GB 10M vectors, overage $0.10/GB storage. Mem0 Free 1k memories, Cloud $49/mo 50k.
State Management / Checkpointing / Session Store
A piece of your stack you may or may not need, depending on scope. Pick the option that fits — or skip it if your project doesn’t require this capability yet.Pricing & free-tier limitsUpstash Redis Free 10k cmds/day 256MB max 1k conn; PayG $10/mo 100k cmds/day 1GB, $0.20/100k cmds overage. Redis Cloud Free 30MB, Essentials $5/mo 100MB $0.20/100k ops. Neon Free 0.5GB storage 3 projects, $20/mo Scale 10GB.
Sandbox Execution Environment (Code execution)
Stores API keys and credentials safely, separate from your code. Leaking secrets is one of the most common breaches.Pricing & free-tier limitsE2B Free 100 hours/mo CPU sandbox, 30 concurrent, 2GB RAM; Starter $25/mo 1000 hours + 10 vCPU, $0.03/vCPU/hr overage + $0.10/GB RAM hr. Modal Free $30 credit/mo (~30 E2B hrs), then $0.000032/vCPU/sec (~$0.12/vCPU/hr). Daytona OSS free 5 workspaces.
Tool/Function Calling Infra (MCP Registry)
A piece of your stack you may or may not need, depending on scope. Pick the option that fits — or skip it if your project doesn’t require this capability yet.Pricing & free-tier limitsComposio Free 500 tool calls/mo 3 MCP custom servers; Pro $49/mo 10k calls $0.005/call overage $0.10/active connection. MCP OSS unlimited. Toolhouse Free 1k calls/mo $25/mo 10k. Zapier 750 tasks free.
Database - Relational (Agent Metadata, Runs)
Persistent storage for your app’s data — users, products, orders. The single most important architectural decision for most projects.Pricing & free-tier limitsSupabase Free 500MB DB 50k MAU auth 2GB egress 1GB file; Pro $25/mo 8GB DB 50GB egress $0.0035/hr compute, storage overage $0.021/GB. Neon Free 0.5GB, 10k compute hours free then $0.16/CU hr. Turso Free 9GB, $29/mo 24GB.
Monitoring & Tracing (Agent Traces)
Tells you when things break and why. You cannot fix what you cannot see — this is how you keep downtime short.Pricing & free-tier limitsLangSmith Free 5k traces/mo 14d retention; Plus $39/mo 10k traces, $0.005/trace overage. Langfuse Free Cloud 50k observations/mo 30d, $39/mo 100k obs $0.003/observation overage. Helicone Free 10k req/mo. Self-host OSS free unlimited.
Secrets Management for Tool Credentials
A piece of your stack you may or may not need, depending on scope. Pick the option that fits — or skip it if your project doesn’t require this capability yet.Pricing & free-tier limitsInfisical OSS free unlimited self-host; Cloud Free 5 projects 100 secrets; Pro $12/seat/mo. Doppler Free 5 users 25 configs; Team $18/user/mo unlimited. AWS Secrets $0.40/secret/mo + $0.05/10k calls. Vault HCP free 25 secrets.
Logging & Observability Platform
Tells you when things break and why. You cannot fix what you cannot see — this is how you keep downtime short.Pricing & free-tier limitsGrafana Cloud Free: 50GB logs/mo 14d retention, 50GB traces, 10k metrics; Pro $8/user/mo + $0.50/GB logs ingestion $0.30/1k hours traces overage. Datadog Free 1-day logs; Pro $15/host/mo APM + $0.10/GB logs. SigNoz OSS free unlimited self-host; Cloud $49/mo 100GB.
Queue for Agent Tasks
Runs slow work (emails, exports, payouts) in the background so users don’t wait. Keeps your app snappy.Pricing & free-tier limitsSQS Free 1M requests/mo (always), then $0.40/1M req ($0.50 FIFO). QStash Free 500 msgs/day 20 DLQ; $10/mo 10k msgs/day $0.01/100 msgs overage. CloudAMQP Free 1M msgs/mo, $20/mo 20M. BullMQ OSS free.
Background Jobs / Workflow Engine for Long-running Agents
A piece of your stack you may or may not need, depending on scope. Pick the option that fits — or skip it if your project doesn’t require this capability yet.Pricing & free-tier limitsInngest Free 50k steps/mo + 100 workflow runs/mo; Pro $20/mo 250k steps $0.00008/step overage. Temporal Cloud Free $200 credit, $0.000025/action + $25/GB storage, $0.24/1M signals. Trigger.dev Free 5k runs/mo then $30/mo 50k.
API Gateway + Rate Limiting for Agent API
Controls and protects your APIs — quotas, abuse prevention, and firewalls. Important once you have real traffic or many clients.Pricing & free-tier limitsCloudflare Workers Free 100k req/day 10ms CPU; Paid $5/mo includes 10M req, $0.30/1M overage $0.02/GB egress. AWS API GW Free 1M calls/mo 12mo then $1.00/1M REST $0.60/1M HTTP. Kong OSS free. Unkey Free 5k verifications/day.
Object Storage for Artifacts & Outputs
Where you keep files users upload or you serve — images, videos, documents — and how fast they reach visitors around the world.Pricing & free-tier limitsR2 Free: 10GB storage, 10M Class A ops 10M Class B; Paid $0.015/GB/mo storage, $4.50/1M Class A $0.36/1M Class B, egress free. S3 Free 5GB 12 months, then $0.023/GB storage + $0.005/1k PUT $0.0004/1k GET. B2 $0.006/GB/mo egress $0.01/GB.
Embedding Service
Powers AI features — model access, embeddings, and inference. Costs scale with usage, so watch the meter.Pricing & free-tier limitsOpenAI Free $5 credit then embedding-3-small $0.02/1M tokens large $0.13/1M. Voyage Free 50M tokens/mo then $0.10/1M (voyage-2). Cohere Free 1k/min then $0.10/1M. Local OSS free unlimited ~500 doc/sec on CPU.
Authentication & RBAC for Agent Access
How users sign up, log in, and are authorized. Getting roles and access control right early prevents painful rewrites.Pricing & free-tier limitsClerk Free 10k MAU, 10 orgs; Pro $25/mo 10k MAU $0.02/MAU overage $10/org overage. Auth0 Free 25k MAU (7.5k SSO), then $35/mo 1k MAU + $0.15/MAU overage. Supabase Auth Free 50k MAU included. Lucia/Better-Auth OSS free.
Prompt Management & Versioning
Powers AI features — model access, embeddings, and inference. Costs scale with usage, so watch the meter.Pricing & free-tier limitsLangfuse Free Cloud includes prompt versioning (50k obs); Pro $39/mo unlimited prompts & git-sync. PromptLayer Free 1k logs/mo, Pro $25/mo 10k logs $0.002/log overage. Pezzo OSS free unlimited self-host.
Evaluation Harness for Agent Success
A piece of your stack you may or may not need, depending on scope. Pick the option that fits — or skip it if your project doesn’t require this capability yet.Pricing & free-tier limitsBraintrust Free 1k evals/mo; Pro $50/mo 10k evals $0.01/eval overage + $0.15/ GB log overage. Promptfoo OSS free unlimited. Ragas OSS free. LangSmith Free 5k traces eval included, Plus $39/mo. Evidently Free 10k evals.
How this small scale agents checklist works.
Each requirement below is something a small scale agents build typically needs. Pick one of the four researched options — recommended, free, cheaper or paid — add your own with "Other", or skip the requirement if your project doesn't need it. Nothing is mandatory; the plan on the right tracks what you've decided so nothing gets forgotten.
Your picks are saved in this browser automatically, so you can come back anytime. Options are researched per build level and refreshed as vendors change their plans — always verify details on the provider's page before committing.