Developer Tools — professional 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)
Controls and protects your APIs — quotas, abuse prevention, and firewalls. Important once you have real traffic or many clients.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
Controls and protects your APIs — quotas, abuse prevention, and firewalls. Important once you have real traffic or many clients.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)
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 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)
Where your code actually runs and serves requests. Picking the right host affects speed, scaling, and how much ops work you do.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)
Where your code actually runs and serves requests. Picking the right host affects speed, scaling, and how much ops work you do.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
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 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
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 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)
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 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)
Tells you when things break and why. You cannot fix what you cannot see — this is how you keep downtime short.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)
Powers AI features — model access, embeddings, and inference. Costs scale with usage, so watch the meter.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)
Powers AI features — model access, embeddings, and inference. Costs scale with usage, so watch the meter.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
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 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)
Lets users find things fast. A slow or missing search directly costs engagement and conversions.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
Powers AI features — model access, embeddings, and inference. Costs scale with usage, so watch the meter.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
Lets external services notify you of events in real time. Core to integrating payments, KYC, and third-party workflows.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)
Moves money — charges, payouts to sellers, taxes, fraud checks. Highest-stakes integration: get it wrong and you break compliance or lose revenue.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)
Understands your users and supports them. Drives product decisions and retention.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
Tells you when things break and why. You cannot fix what you cannot see — this is how you keep downtime short.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
Tells you when things break and why. You cannot fix what you cannot see — this is how you keep downtime short.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
CI/CD for SDKs & API (Multi-language SDK releases)
Automates testing and deploying your code. Saves enormous time and prevents “works on my machine” releases.Pricing & free-tier limitsGitHub Actions Free 2k Linux min/mo (1k private), Pro included $4/user/mo 3k min, overage Linux $0.008/min, Windows $0.016/min, macOS $0.08/min | CircleCI Free 6k credits/mo (~1k min), Performance $15/mo 30k credits + $15/25k extra | Buildkite Free 1 agent free, Team $35/agent/mo
Symbol Server / Source Maps for SDK Debug
Where your code actually runs and serves requests. Picking the right host affects speed, scaling, and how much ops work you do.Pricing & free-tier limitsSentry Free 5k errors/mo 1M transactions + 1GB attachment storage $0.20/GB over | Team $26/mo 50k errors 100k txns + $0.60/1k errors over | R2 free 10GB storage + 10M Class A ops/mo, then $0.015/GB-mo storage + $4.50/M Class A $0.36/M Class B, egress free | Symbolicator OSS $0
GPU Compute (A100/H100) for Custom Model Inference & Fine-tuning
Where your code actually runs and serves requests. Picking the right host affects speed, scaling, and how much ops work you do.Pricing & free-tier limitsColab Free T4 15GB ~12hr/d limit, Pro $9.99/mo 100 CU | RunPod A100 40GB $1.19/hr on-demand spot $0.79/hr, A100 80GB $1.89/hr spot $1.29/hr, H100 $2.50/hr spot $1.89/hr | Vast.ai RTX4090 $0.35/hr spot $0.25/hr, A100 $0.79/hr, H100 $1.99/hr spot | AWS p4d 8x A100 $32.77/hr = $4.09/GPU/hr, p5 H100 8x $98/hr = $12.25/GPU/hr | CoreWeave H100 $4.25/hr reserved $3.25/hr 1yr
Inference Hosting (Serverless GPUs - Anyscale, Modal, Replicate)
Where your code actually runs and serves requests. Picking the right host affects speed, scaling, and how much ops work you do.Pricing & free-tier limitsModal Free $30 credits/mo ~30 GPU hrs T4 ~10 hrs A10G, A10G $0.65/hr ($1.10 A100), A100 40GB $1.40/hr, H100 $2.75/hr billed per second + $0.10/M requests | Replicate $5 free then A100 $0.000725/sec = $2.61/hr + $0.10/1k API | Anyscale free $10 credits, A10G $1/hr endpoint, A100 $2.50/hr + $0.12/M tokens | Baseten $0.40/hr replica + GPU cost $1.20/hr A10G
Model Registry & Versioning (Model Hub)
Powers AI features — model access, embeddings, and inference. Costs scale with usage, so watch the meter.Pricing & free-tier limitsHF Hub free public 300GB storage unlimited models, Pro $9/mo 100GB private + $0.08/GB over, Enterprise $20/user/mo custom storage | MLflow Model Registry OSS $0 self-host Postgres 100GB | Vertex AI Model Registry $0.05/model version/mo + $0.40/GB storage + $0.12/GB egress | overage W&B Model Registry included in $50/user
Experiment Tracking / MLOps (W&B, MLflow)
Ships features to a subset of users or toggles them without redeploying. De-risks releases and enables experiments.Pricing & free-tier limitsW&B Free 100GB tracked data 1 team, Team $50/user/mo 250GB pooled + $0.30/GB over + $25/user extra | MLflow OSS $0 self-host 50GB Postgres | Comet free 1 user 100GB, Team $39/mo 250GB over $0.20/GB | TensorBoard + GCS free 5GB then $0.023/GB | Neptune free 25GB 1 user, Team $49/user/mo 100GB
Prompt Registry & Version Control (PromptLayer)
Where your source code lives and is collaborated on. Non-negotiable for any team or serious project.Pricing & free-tier limitsLangfuse free 50k observations/mo includes prompts, Core $39/mo 150k obs, Pro $199/mo 500k + $8/100k over | PromptLayer free 5k requests/mo, Starter $40/mo 50k reqs + $0.60/1k over, Pro $199/mo 500k | Humanloop free 10k generations/mo, Pro $99/mo 100k generations $0.60/1k over, Enterprise $995/mo
Tracing / Distributed Tracing for LLM Chains & Tool Calls
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, Plus $39/user/mo 10k traces + $0.50/1k extra, Pro $15/1k traces over 50k | Honeycomb Free 20M events/mo 7d retention, Pro $100/mo 100M events $0.15/M over | Jaeger OSS $0 self-host 100GB storage | Datadog APM $31/host/mo + $1.70/M indexed spans, 15-day retention $1.50/ M extra
Caching Layer (Semantic Cache via Redis / GPTCache)
Stores frequent results in fast memory so you serve less from the database. Big lever for speed and cost.Pricing & free-tier limitsUpstash Free 10k cmds/day 256MB storage, Standard $10/mo 100k cmds/day 1GB + $0.20/100k over | Redis Cloud Free 30MB, $5/mo 1GB essentials + $0.25/100k commands, Pro $0.125/hr 1GB + $0.20/100k | Momento free 5M ops/mo, $0.50/M reads $0.20/M writes over | Dragonfly OSS $0 self-host ~0.10ms latency | Elasticache Serverless $0.125/GB-hr
Object Storage for Datasets & Eval Artifacts
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 $0 egress, then $0.015/GB-mo + $4.50/M Class A + $0.36/M Class B, egress free | S3 free 5GB 20k GET 2k PUT 12mo, then $0.023/GB-mo first 50TB + $0.09/GB egress + $0.0004/1k GET $0.005/1k PUT | B2 $0.006/GB-mo + $0.01/GB egress (free to CF) + $0.005/1k downloads | Wasabi $6.99/TB no egress
Message Queue / Streaming for Inference Workloads (Kafka, SQS)
Runs slow work (emails, exports, payouts) in the background so users don’t wait. Keeps your app snappy.Pricing & free-tier limitsUpstash Kafka free 10k msgs/day 1 topic, Standard $10/mo 100k msgs/day + $0.01/10k over | SQS free 1M req/mo then $0.40/M req + FIFO $0.50/M | Cloudflare Queues free 1M ops/mo then $0.40/M + $0.015/GB | Redpanda free trial 30d, Starter $199/mo 5TB storage + 100 partitions, $0.10/GB over | Confluent Cloud free $400 credits trial then $1.50/hr cluster + $0.11/GB
How this professional developer tools checklist works.
Each requirement below is something a professional 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.