stop prompting. start specifying
Most AI builders ship a v0.
fromSpec takes you to v1
fromSpec is a spec-driven AI app builder: one conversation becomes a spec you approve, then a real codebase you keep evolving.
conversation → a spec you approve → a real marketplace
the problem
The v0 looks done. The codebase isn't.
Prompt-and-pray feels fast until you lose track of what you built. The build is a black box until it ships. Every fix is one more prompt that can rewrite code you never touched, and your only record of intent is a chat log nobody can review.
Build self-serve analytics with funnels and cohort retention.
Add weekly retention by signup cohort.
⚠ Also renamed your event schema. You never asked for that.
Your intent lives in a history you can't review.
the spec
Intent in.
Blueprint out.
Code last.
Your conversation compiles into one structured file: entities, flows, screens, branding. Readable, diffable, version-controlled. The source of truth, not the chat log.
the data models your product is built on
the actions people can take
every page fromSpec will build
who can do what, and who can't
{ "appName": "Plotline", "version": "0.2", "entities": [ "Event", "Person", "Funnel" ], "flows": [ "funnels", "retention", "cohorts" ], "screens": [ "Dashboard", "Funnels" ], "roles": [ "member", "admin" ], "branding": "azure + slate", "api": "REST · 37 routes", "stack": "React · FastAPI · Postgres"}
colors, type, and theme
the REST endpoints it generates
framework, runtime, and database
every change is diffable and reviewed
see it build
Watch a real v1 get built.
A real build of Plotline, end to end. It's spec-driven, so it stays evolvable: change the spec, recompile, nothing drifts.
iteration
Change the spec, not the prompt.
When Plotline needs to grow, you edit one file and recompile. Every change is a diff you review: version-controlled, deterministic, no re-prompting. Nothing drifts.
the difference
A contract you approve, not a guess you debug.
Both turn intent into an app. Only one lets you review the intent before it becomes code.
| fromSpec | Prompt-to-code tools | |
|---|---|---|
| Approve before code | A structured spec.json contract | A prompt |
| Review intent first | Read & approve the spec | Baked straight into code |
| Code ownership | You own the FastAPI + React (or Next.js) source | Often tied to the platform |
| Lock-in | None. Take it and leave. | Common. It runs in their environment. |
| Re-run determinism | Same spec compiles the same | Re-running can differ |
| Bring your own model | OpenAI · Anthropic · Google | Often fixed to their provider |
| Token cost | Pay the provider directly | Often metered with a markup |
| Requirements change | Edit the spec, recompile | Re-prompt and debug |
what you get
Own everything. No lock-in.
Plug in your own model, approve the spec before it builds, and ship a real codebase that runs anywhere.
model · BYOK
Bring your own key
OpenAI, Anthropic, or Google on your own API key — encrypted at rest, billed by your provider.
code
You own the source
- Download the ZIP or push straight to your GitHub
- Run it anywhere — no runtime dependency on fromSpec
-
Keys encrypted
Stored encrypted at rest. We never see them.
-
You approve first
Sign off the spec before it builds.
-
No lock-in
Take the code and leave. Host it anywhere.
-
No token markup
Pay your provider directly. We never touch the bill.
pricing
Start free. Own everything.
Bring your own model and pay your provider directly. No token markup, no lock-in. Your code is yours on every plan.
Free
Run the full pipeline on your own keys: chat to spec to a real app.
Start building free- ✓ 1 active project
- ✓ Full pipeline
- ✓ Bring your own key (BYOK)
- ✓ Own the code
free forever
- ✓Everything in Free
- ✓Unlimited projects
- ✓GitHub / GitLab sync
- ✓Spec version history
- ✓One-click deploy
- ✓Priority support
- ✓Everything in Pro
- ✓Collaborative spec review
- ✓SSO + audit logs
- ✓Gate approval trail
- ✓SLA support & onboarding
Every plan includes the full pipeline and your own API keys (BYOK).
faq
Straight answers.
The questions you ask before you trust a generator.
Do I own the code, or am I locked in?
You own it. Download the codebase as a ZIP, or push it straight to your GitHub. It's a real fastapi · react · postgres (or next.js) project. Run it and host it anywhere, with no runtime lock-in.
Which AI models can I use?
Bring your own. Plug in OpenAI, Anthropic, or Google with your own keys, encrypted at rest and billed by your provider. Swap models any time without re-architecting.
Is this just a wrapper around an LLM?
No. What you approve is a structured spec.json (entities, flows, screens, branding, stack) that you can actually read, and it compiles to source you can open. A wrapper hands you the model's raw output. fromSpec hands you a contract you approved and a deterministic build from it.
Does it really not drift?
The spec is the contract. Code is generated from the approved spec.json, so it can't quietly change things you didn't ask for. Want a change? Edit the spec and recompile. The diff shows exactly what changed.
Can I edit the generated code? Will fromSpec overwrite it?
Edit freely. Mark the files you've customized with @fromspec:lock and regeneration leaves them alone. Everything else regenerates from the spec, so you update requirements and evolve, without losing hand-tuned edits.
Is it deterministic, or random?
Deterministic by design. The same approved spec compiles the same way; re-running isn't a fresh roll of the dice. The spec is the source of truth, and the compile never reinterprets it.
Is this for non-technical people?
It's built for technical founders and developers who want speed without losing control. You won't write code, but you will read and approve a spec, so a working understanding of what you're building helps.
What does it cost, and how do I get in?
fromSpec is in early access now. You'll always bring your own key (BYOK) and pay your provider directly, so we never mark up model usage. Request an invite to start building.
conversation → a spec you approve → a real app
Stop prompting. Start specifying
fromSpec is in early access. Request an invite and compile your first spec.
One email. No spam, no sharing, leave anytime.