Free agent skill for Claude Code, Cursor and Codex
A stack that fits your project, and keeps fitting as it changes.
For developers and small teams who pick their own services. It fits the stack to your budget, users, data rules and team, then checks every change: new services, plan limits, bills.
Then ask the agent to run manifestack in your project.
npx manifestack install --agent codex
Then run $manifestack in your project.
npx manifestack
Detects your agents and asks where to install: Copilot, Windsurf, OpenCode, Cline and more.
npx skills add manifestack/manifestack
Installs the skill without the new-service hook. In Claude Code and Cursor, /manifestack offers to add it.
MIT
No API keys
Read-only
Runs locally
Stacks don't break on day one. They drift out of fit.
A requirement gets missed in a quick setup. The agent adds a service nobody checks. The plan is too small for the load, or the setup far too big. Nobody re-checks the fit until something breaks.
Outgrown
Read-only
Supabase Free caps the database at 500 MB. At 2 MB a day, that's months away. Then a launch, or a log table nobody trims, adds 365 MB in three weeks, and the database goes read-only: no signups, no orders.
500 MB
On the +2 MB/day trend: week 33Actual: week 11
Missed requirement
EU vs free tier
A prototype sent user documents to the Gemini API on the free tier, and production kept it. Free-tier content can go into improving Google's products, and EU users need the paid tier. Your contract promises no training on customer data.
requires
no training on customer data
ai plan
Gemini API, free tier
✕
Unchecked change
2 auth providers
Asked to add login, the agent installs Clerk. Supabase Auth already signs users in. Now users live in two places, and one of them bills per user.
"@supabase/supabase-js": "^2"
+ "@clerk/nextjs": "^6"
Nothing failedNothing was checked
Overbuilt
~$310 vs ~$25
A Kubernetes cluster, a multi-zone database, a NAT gateway and a load balancer, serving 40 users. A single app host and managed Postgres would carry them. Big clouds are the right call at scale. Not at forty users.
Built for 1M users~$310/mo
Right-sized for 40~$25/mo
Same app, same 40 users~$3,400/yr extra
There's no best stack. There's yours.
Budget, users, data rules, what your team prefers and what it won't touch decide the fit, from the framework to the cloud. Manifestack starts there, so the same question gets a different answer.
Solo founder, content site and waitlist
budget
under $25/mo
users
500 → 5k
requires
nothing special yet
prefer
React, Firebase
avoid
servers to maintain
fits
Astro, static pages, no server to run
Supabase Free, database and auth in one
Resend Free
revisit_when users > 3k
Team of four, B2B dashboard behind login
budget
~$600/mo
users
20k → 100k
requires
EU database, SOC 2 vendors
prefer
Postgres, AWS
avoid
Kubernetes, ops on-call
fits
React + Vite, client-side app, no SSR needed
API and Neon Postgres in Frankfurt
Resend Pro
revisit_when monthly bill > $500
Indie mobile app with subscriptions
budget
under $100/mo
users
5k → 50k MAU
requires
App Store and Google Play billing
prefer
React Native, Expo
avoid
running own servers
fits
Expo with EAS Build and Update
RevenueCat for in-app subscriptions
Supabase Free, database and auth
revisit_when mau > 40k
Illustrative profiles. Your answers go into STACK.md, and every later audit and every new service is checked against them.
The whole product, not one package.json.
Frontend, backend, workers, infrastructure and every third-party API. Each service is sorted by role and checked against your requirements and the vendor's pages today.
1 · Reads
web/package.jsonNext.js · Clerk · Supabase
api/requirements.txtFastAPI · OpenAI · Stripe
worker/go.modStripe · Resend · Sentry
vercel.jsonhosting
Dockerfile · infra/*.tfinfrastructure
.envvariable names, never values
2 · Sorts by role
Hosting
Vercel
Database
Supabase
Auth
Clerk + Supabase Authsame job twice
Payments
Stripe
Resend
Monitoring
Sentry
AI
OpenAI
3 · Checks against
.manifestack/STACK.md
budget, users, requires, prefer, avoid
vendor pages, read today
pricing, limits, regions, certifications
Findings
Requirement
Overlap
Overbuilt
Limit
Bill
Risk
Set the fit once. Every change gets checked against it.
Know the project
budget, users, rules, team
Starts from what the stack has to fit: budget, expected users, data region and certifications, what the team prefers and what it avoids.
Check the fit
/manifestack audit
Reads vendor pages today and reports what no longer fits: requirement gaps, overlaps, overbuilt setups, limits and bills, each with a date, a cost and a fix.
Remember why
.manifestack/STACK.md
Keeps the requirements, decisions and their reasons in your repo, so the next session and the next developer start from the same facts.
Check every change
hook in Claude Code, Cursor
When the agent adds a vendor, it is checked against your requirements, your avoid list and the services you already run, before you rely on it.
Empty repo
Describe what you're building: budget, expected users, data rules, what your team prefers and avoids. Manifestack proposes a stack, explains each pick and prices it as you grow.
Example: Next.js on Vercel, Supabase, Resend
1k users
$0/mo
10k users
$65/mo
100k users
~$420/mo
/manifestack init
Existing project
Point it at any repo, yours or a client's: frontend, backend, workers and infrastructure. It maps what's wired up and checks it against your requirements and usage: data region, duplicated services, overbuilt setups, limits and costs.
/manifestack audit
Every change
Say you ask the agent to add login and it installs Clerk. The hook checks the new SDK against STACK.md, and the agent tells you before it finishes:
- "@clerk/nextjs": "^6"
Clerk (auth) added. Supabase Auth already signs users in: an Overlap. Clerk bills per user; check it against the ~$600/mo budget.
hook in Claude Code, Cursor
Every finding says when it matters and how to fix it.
Output of /manifestack audit on a sample product: a Next.js frontend, a Python API and a Go worker, 9,000 monthly users, seven services. Requirement gaps, duplicated services, launch risks, limits and bills, each with a fix you can act on.
~/relaylog/manifestack auditSample output
FindingWhenCostFix
Requirement
Supabase project region vs. EU database rule
Project in us-east-1, STACK.md requires EU
When
Before launch
Cost
~1 day of migration
Fix
Create the production project in an EU region and move the data while it is still small.
Overlap
Two auth providers: Clerk and Supabase Auth
@clerk/nextjs and supabase.auth both in web/src/
When
Now
Cost
$25/mo on Clerk Pro, more past 50,000 MRU
Fix
Both do the same job here. Keep the one whose features you use and remove the other from the code.
Risk
OpenAI usage tier 1: tokens per minute
api/ summarizes every upload; the launch-day estimate is above the tier limit
When
Launch day
Cost
Higher tiers need paid history and time
Fix
Request a tier increase now, queue uploads in the worker, and use a smaller model for short summaries.
Limit
Supabase Free: database size
312 / 500 MB, +1.1 MB/day
When
ETA ~Mar 2027
Cost
$25/mo on Pro
Fix
Archive events rows older than 90 days, or schedule the upgrade for February.
Bill
Vercel Pro: data transfer
3.4 TB last month, 1 TB included
When
Every month, growing
Cost
~$360/mo overage
Fix
Cache /og/* images at the edge and set Cache-Control on /api/feed.
Fix first
EU region, before launch
Spend to review
$385/mo ($4,620/yr)
Checked against
EU, SOC 2 · 7 pages, Oct 6
Usage figures come from numbers you give it, exports in the repo or a read-only vendor MCP. A report is as current as those inputs.
Manifestack commands
Two to start. Plain /manifestack picks the right one: init for an empty repo, audit for an existing one. In Codex, use $manifestack; in other agents, ask for the skill by name.
Command
What it does
Example
Available now
/manifestack init
New project: asks what the stack has to fit, proposes one priced at 1k, 10k and 100k users, and writes the first STACK.md.
/manifestack init "B2B dashboard, EU users"
/manifestack audit
Existing project: checks every service against your requirements and growth and reports what no longer fits, each with a when, a cost and a fix.
/manifestack audit
Coming next
/manifestack compareplanned
Two vendors side by side for your workload: features, limits, region, certifications, lock-in, price.
/manifestack compare neon supabase
/manifestack migrateplanned
A step-by-step plan for a vendor or plan switch, with a rollback.
/manifestack migrate supabase --to pro
/manifestack watchplanned
Re-reads vendor pages for the services in STACK.md and proposes a diff when something changed.
/manifestack watch
.manifestack/STACK.md
## Requirements
budget: ~$600/mo
users: 9k now, 50k by Q3
requires: EU database, SOC 2 vendors
prefer: Postgres, Next.js
avoid: Kubernetes # no ops on-call
## Database: Supabase
plan: free
limit: 500 MB database, s after 7 days idle
source: supabase.com/pricing # read 2026-10-06
usage: 312 MB, +1.1 MB/day (2026-10-06)
decided: stay on Free until first paying user
revisit_when: db_size > 400 MB OR date >= 2027-02-01
next: Pro, $25/mo
env: SUPABASE_URL, SUPABASE_ANON_KEY # names only
## Email: Resend
plan: pro, $20/mo
limit: 50,000 emails/month
revisit_when: monthly_sent > 45,000 OR before launch
One file, versioned with your code.
STACK.md lives in .manifestack/, the only folder the skill writes to. The skill tells your agent to read it before changing infrastructure. You review it in pull requests.
revisit_when
A condition, not a reminder. Every audit checks it and flags the section once it's true.
Stored
Your fit: budget, users, data rules, what the team prefers and avoids
Services, plans and the limits that apply
Usage snapshots with the date they were taken
Decisions and the reason behind each one
Env var names, so the agent knows what is wired
Never stored
Secret values, API keys or tokens
Connection strings or passwords
Customer data or anything from your database
Billing details from vendor accounts
Your keys never leave your machine. Neither does your code.
By default it needs no account access, and its only network calls read vendors' public pages: pricing, limits, regions and certifications. A read-only vendor MCP is your own connection, used only if you set it up.
Your machine
Repo scan and analysisruns in your agent session
.manifestack/STACK.mdwritten to your repo
Usage numbersyou give them, or a read-only vendor MCP
Never sent anywhere by Manifestack
Source code
API keys and .env values
Account logins or OAuth access
Usage and billing data
GET public pagespublic page only
Vendor public pages
Pricing, regions and security pages, such as supabase.com/pricing. Read during the audit like any visitor would. Requests carry no project data.
Your agent's model provider sees what your agent already sees. Manifestack adds no new destination.
Pricing, limits and regions, read from the source.
Page maps for hosting, database, auth, email, storage, payments, mobile, monitoring and AI. Each audit reads the vendor's current pages for plans, limits, regions and certifications. No rankings, no affiliate links, no "switch to X".
The skill finds the vendor's public pages during the audit. A page map makes it faster; new ones ship as releases.Request a map
Frequently asked questions
Who is it for?
Developers, small teams and agencies who build with Claude Code, Cursor or Codex and choose their own services: hosting, database, auth, email, payments, AI APIs. It helps most from the first commit to a few hundred thousand users, when nobody owns infrastructure full-time.
How is this different from asking my agent?
A plain agent answers from training data that can be a year old, then forgets the answer. Manifestack starts from your project's requirements, reads vendors' current pages, keeps every decision in STACK.md, and checks each later change against them.
Will it change my code, config or vendor settings?
No. The audit is read-only. The only thing it writes is .manifestack/STACK.md, and decisions in it (plan, revisit dates) only after your yes. Installing a package or changing a setting happens only when you ask your agent for it.
Do I need to give it API keys or account access?
No. It reads your repo and env var names, never their values, and asks you for usage numbers. If you've connected a vendor's official MCP in read-only mode, such as Supabase, Neon or PostHog, it can read usage there instead. Manifestack itself never asks for a key or a login.
Does it work with Cursor, Codex or my agent?
Yes, if your agent reads Agent Skills (SKILL.md). Cursor, Codex, GitHub Copilot, Windsurf and OpenCode do, and npx manifestack finds them for you. The new-service check is dependable in Claude Code and Cursor, where a hook flags every vendor SDK the agent adds. In other agents it depends on the agent picking up the check on its own, so run /manifestack audit before you merge a change that adds or swaps a service.
Does it work with Python, Go or mobile apps?
Yes. It reads dependencies from package.json, requirements.txt, pyproject.toml, Pipfile and go.mod, plus config files and env var names in any project. React Native and Expo apps are covered, including RevenueCat, Adapty and EAS. Native iOS and Android dependencies (Podfile, Gradle) are not read; the skill asks about services it cannot see.
Where do prices and limits come from?
From each vendor's public pages (pricing, limits, regions, certifications), read during the audit. Every finding cites the page and the date it was read. If a page can't be fetched, the finding says so instead of guessing. Needs an agent with web access.
What does it check besides costs?
The fit itself: data region and certifications against your requirements, services that do the same job, setups far bigger than the load, and what the team prefers or avoids. init proposes a whole stack and explains each pick, including when Next.js or a big cloud is more than you need. Compliance decisions stay yours.
My vendor isn't on the list. Is it still useful?
Yes. The skill looks up its public pages and records the service, plan and limits in STACK.md. A page map makes it faster and more reliable. To add one, open an issue with the pricing page.
Is it free?
Yes. MIT license, no paid tier, no account. There is no Manifestack server to pay for.