Stack Cost AI

Developer Toolssmall 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.

API Gateway for Model APIs (10k req/s)

Pricing & free-tier limitsKong OSS $0 self-host 10k req/s/node | AWS Free 1M calls/mo 12mo, then $3.50/M reqs + $0.09/GB egress + $0.90/M cache | Kong Enterprise $2,500/mo/gateway + $0.10/1k reqs over 100M | Apigee X $500/mo base + $25/M API calls

Rate Limiting + WAF / DDoS Protection for Model API

Pricing & free-tier limitsCloudflare Free: 5 WAF custom rules, 1 rate limit rule 10s period 100k req/day free | Pro $20/mo 20 rules | Business $200/mo 100 rules | AWS WAF $5/webACL + $1/rule/mo + $0.60/M reqs, Shield Advanced $3k/mo | Cloudflare Enterprise $5,000/mo unlimited, $0.05/10k good reqs overage, 100ms mitigation

SDK Registry (npm, PyPI, Maven Central)

Pricing & free-tier limitsnpm free public unlimited bandwidth, Pro $7/user/mo private pkgs 5GB storage | PyPI free unlimited | Maven Central free via Sonatype, 10GB/stage | GH Packages Free 500MB storage + 1GB transfer, then $0.25/GB storage + $0.50/GB transfer | JFrog Pro $45/mo 10GB storage 10TB transfer, $0.10/GB extra

Documentation Hosting (ReadMe, Mintlify, Docusaurus)

Pricing & free-tier limitsDocusaurus OSS $0 + Vercel Hobby free 100GB bandwidth 6000 exec hrs | Mintlify Free 1 project 2k pageviews/mo, Starter $120/mo 10k views + $20/5k overage, Growth $350/mo 100k views | ReadMe $99/mo 10k monthly visits + $0.01 per extra visit | Algolia DocSearch free for OSS maintained projects

Code Sample / Playground Hosting (AI Chat Playground)

Pricing & free-tier limitsStackBlitz Free 5 projects, Pro $12/user/mo unlimited private | CodeSandbox Free 30 sandboxes, Team $12/mo 200 sandboxes | Replit free 0.5 vCPU / 1GB RAM 10GB storage, Hacker $7/mo 4GB always-on + $0.20/GB outbound | Vercel Hosting for playground Hobby free 100GB bandwidth, Pro $20/seat/mo + $40/100GB overage

Artifact Registry for SDK Binaries & Container Images

Pricing & free-tier limitsGHCR free 500MB private storage + 1GB transfer (public unlimited), $0.008/GB-day over + $0.50/GB egress | Docker Hub free 1 private repo, Pro $5/mo 5 private 50GB | AWS ECR $0.10/GB-mo storage free 500MB, $0.09/GB transfer, $0.40/1k API calls | GCR/GAR $0.10/GB-mo + $0.12/GB egress, free 0.5GB

Feature Flags for API Versions & Rollouts

Pricing & free-tier limitsFlagsmith OSS $0 self-host unlimited flags | Flagsmith Cloud Free 50k req/mo, Starter $45/mo 250k reqs $0.10/1k over | Unleash OSS $0, Cloud free 2k events/d, Pro $80/mo 50k events | GrowthBook free 20k tracked users/mo, Pro $20/mo 100k | LaunchDarkly free 1k MAU, Pro $8.33/1k MAU/mo, Enterprise $20k/yr start + $0.01/flag eval over 10M

Evaluation Harness (LangSmith, Promptfoo, Braintrust)

Pricing & free-tier limitsPromptfoo free unlimited evals self-host | Braintrust Free 5k eval logs/mo 2 users, Pro $200/mo 100k logs + $0.02/1k over + 10 users, Scale $1,000/mo 1M logs | LangSmith Free 5k traces/mo, Plus $39/user/mo 10k traces, overage $0.50/1k traces | DeepChecks free OSS

Monitoring for LLM Calls (Helicone, Langfuse, Portkey)

Pricing & free-tier limitsHelicone Free 100k LLM log events/mo 7d retention, Pro $20/mo 1M logs 30d + $5/100k over, Enterprise $750/mo 10M + custom | Langfuse Free 50k observations/mo, Core $39/mo 100k obs, Pro $199/mo 500k obs + $8/100k over | Portkey Free 10k calls/mo, Growth $100/mo 100k calls $0.80/1k over, semantic cache included

Logging for Prompts & Completions (Prompt Logging)

Pricing & free-tier limitsLoki OSS $0 self-host 50GB/day | Axiom free 500MB/day ingest (15GB/mo), Pro $25/mo 10GB/day inclusive $0.25/GB over + $0.10/GB query | Better Stack free 1GB/mo 3d retention, Pro $24/mo 10GB 30d + $1.50/GB over | Datadog free 1GB/day, then $0.10/GB ingest + $0.10/GB storage/mo + $1.70/M indexed

Secrets Management for Provider Keys (LLM API Keys)

Pricing & free-tier limitsInfisical OSS $0 unlimited secrets self-host | Doppler Free 100 secrets first project | Infisical Cloud Free 3 projects 50 secrets, Pro $40/mo 20k secrets | AWS Secrets Manager $0.40/secret/mo + $0.05/10k calls, free trial 30d | Vault HCP $0.03/hr dev + $0.095/secret/mo + $0.025/10k accesses, Starter $160/mo

Vector Database for Docs Search & RAG Eval

Pricing & free-tier limitsPinecone Free 100k vectors 1 index (Starter 2026), Standard $70/mo 1M vectors incl 2GB + $0.40/M reads $0.096/GB storage $4.50/M writes | Qdrant Free 1GB RAM ~1M 768d vectors, Starter $25/mo 2GB + $0.12/GB-hr over + $0.045/M requests | Supabase pgvector free 500MB DB, Pro $25/mo 8GB | Weaviate Serverless free 14d, $25/mo 2M vectors + $0.05/M queries

Search for API Docs (Algolia, Typesense)

Pricing & free-tier limitsAlgolia DocSearch free for public docs approved | Community free 10k searches/mo 1M records/mo | Growth $1 per 1k search requests + $0.50/1k records, Standard $0.50/1k searches | Typesense Cloud free 500k docs 100k searches/mo, $40/mo 5M docs 1M searches + $0.04/1k over, Enterprise $399/mo | Meilisearch Cloud $30/mo 100k docs

Background Jobs for Async Evals & Batch Inference

Pricing & free-tier limitsInngest Free 100k runs/mo 100 steps/run 7d history, Pro $20/mo 250k runs + $0.30/1k runs over $0.08/1k steps | Trigger.dev Free 3k runs/mo 150 queue depth, Pro $30/mo 25k runs $12/1k over | Upstash Redis Free 10k cmds/day, Pay $10/mo 100k cmds/day $0.20/100k over | Cloudflare Queues free 1M ops/mo then $0.40/M + $5/M GB

Webhooks + Event Bus for Eval Completion & Callbacks

Pricing & free-tier limitsSvix Cloud Free 50 msgs/day 10 endpoints 3d retention, Growth $100/mo 50k msgs incl + $1.50/1k over, Business $400/mo 250k msgs | Hookdeck free 100 events/day 500/month, Team $25/mo 50k events + $0.50/1k over | EventBridge free up to 14M custom events (always free 100+), then $1.00/M events + $0.20/M for EventReplay

Billing / Metered Usage for API (Stripe Billing)

Pricing & free-tier limitsStripe Billing 0.7% of billed volume (free first 25 invoices/mo, then $0.40 per invoice) + metered billing free to track, 0.5% for revenue recognition | Lago OSS $0; Cloud Free 10k events/mo, Growth $200/mo 100k events + $0.02/100 events over; Chargebee free up to $100k revenue, Growth $599/mo + 0.75% overage | Orb free 10k events, $500/mo base

Customer Support / Ticketing (Intercom, Plain for DevTools)

Pricing & free-tier limitsPlain Free 3 seats 1k customer threads/mo, Growth $60/mo/seat 3k threads incl $0.05/thread over | Crisp Free 2 agents, $25/agent/mo Essentials unlimited chats | Intercom Starter $74/mo 1 seat 500 contacts + $0.02/contact over, Pro $395/mo 3 seats + $15/seat extra | Zendesk Team $19/agent/mo

Uptime Monitoring for Model API Endpoints

Pricing & free-tier limitsBetter Stack Free 10 monitors 3-min interval 3mo retention | Pro $24/mo 50 monitors 30-sec + SMS credits $0.03/SMS over | Checkly Free 10k checks/mo 1 user, Team $32/mo 50k checks + 5 users $7.50/10k extra | Datadog Synthetics $5/1k API tests/mo, $12/1k browser tests | UptimeRobot free 5-min checks 50 monitors

Status Page for API Incidents

Pricing & free-tier limitsUpptime free 100% GitHub compute free, 7-min interval | Instatus Free 1 page 100 subscribers, Starter $29/mo 500 subs unlimited incidents, Growth $79/mo 2k subs + $1/1k over | Atlassian Statuspage Hobby $29/mo 250 subs + $0.02/sub over, Startup $99/mo 1k subs | Incident.io $49/mo 250 subs

Options and prices come straight from our research sheets for a small scale developer tools project. Prices are estimates and change often — always confirm on the provider's page before committing.

How this small scale developer tools checklist works.

Each requirement below is something a small scale developer tools 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.