GGutencode
the printing press for code

Agent-ready backend code — done for you.

Gutencode is an agent-ready backend spine — auth, billing, tenancy, an AI runtime and 35+ more domains, built identical in Python · Go · Node and shipped with its own one-command verifier. Clone it, run verify.py, build on top.

gutencode — verify
ready

// the same audited spine, printed in python · go · node…

// …then it proves itself: python verify.py

01
Get

Get your agent to import the code

02
Customize

It uses AGENT.md + CUSTOMIZE.md to add your features

03
Launch

Save weeks of building — launch faster

built on the standards you already trust — not reinvented

self-verifying — don't trust us, run it one behavior, three languages, parity-verified deterministic · byte-for-byte reproducible
OWASP ASVSStripeIETF Idempotency-KeyStandard WebhooksOAuth 2.0OpenAPIPostgres / SupabaseAuth0 · Clerk interop

Gutencode implements these specs so you don't have to. Names shown are the standards and tools the spine targets — not endorsements.

core backend

The hard parts: Auth, Stripe, AI, Agents & 30+ more — done for you.

35+ audited domains — the parts you'd dread building, already built and battle-shaped. All proven, all in Python · Go · Node.

Auth

world-class

Sessions, password reset, email verify, token rotation — the part everyone ships subtly broken.

ASVS-shaped · no plaintext · rotate + revoke, ×3

RBAC

world-class

Deny-by-default access control that never leaks across roles.

least-privilege, enforced

Tenancy

world-class

Multi-tenant isolation — one cross-tenant read and you're on the news.

tenant-scoped rows (models Postgres RLS)

Stripe

world-class

Payments where a double-charge or a replay is a refund war.

idempotent per caller · signature-verified

Ledger

Double-entry money movement that has to balance, every time.

debits == credits, proven by exit code

AI Agents

world-class

A ReAct agent loop that can't spin forever or fire an unsafe tool.

the loop provably terminates · tool-safe

Idempotency

world-class

Replay-safe writes so a retried request never double-acts.

IETF Idempotency-Key · replays are no-ops

Audit Log

world-class

Tamper-evident evidence for every privileged action.

append-only · tamper-evident

Webhooks

world-class

Signed delivery with rotation + replay-dedup (Standard Webhooks).

multi-secret rotation · replay-deduped

every domain in the spine

world-class hardened

Identity & Access

AuthRBACTenancyOrgsTeamsUsersInvitationsAPI KeysOAuth 2.0

Money & Billing

StripeLedgerPaymentsInvoicesBillingLLM Spend Meter

AI & Agents

AI AgentsTool BeltLLM GatewayWorkflowsMulti-agentRAGVector Store

Data & Infrastructure

RecordsObject StorageSecrets VaultSearchEmailJob QueueNotificationsHealth

Reliability & Governance

IdempotencyAudit LogWebhooksRate LimitFeature FlagsSettingsAdmin+ growing →
agent ready

Build your own Agents — rails included.

A real agent runtime — tools, retrieval, multi-agent orchestration and spend tracking — with the guardrails built in and proven by the same verify.py, across Python, Go & Node.

An agent that reasons, calls tools & remembers

world-class

Create one with a system prompt, give it a session, and run the loop — it thinks, calls your tools, reads the results, and keeps the conversation in memory until it answers. A few endpoints, ready to run.

reasoning looptool callingsession memorymulti-turn

what you get

Tool Belt

Hand your agent a typed tool belt — it calls them with validated args and gets structured results back. Drop your own in behind the same seam.

RAG + grounding

Feed it your documents — it chunks, embeds and retrieves the right passages, then answers with citations back to the source.

Workflows & crews

Go beyond one agent — chain multi-step workflows and hand off between named agents in a crew.

the rails — what it won't let happen

Bounded

Every loop — agent, workflow, crew — is capped. Nothing spins forever.

Tool-safe

Only registered tools run. A code-injection attempt is a no-op, not an exec.

Spend-metered

Cost is server-derived from a price table — no client-set prices, no double-charge.

Grounded

Citations point to real, in-bounds source text — never fabricated or stale.

Runs and tests fully offline with a deterministic stand-in model — no API keys in CI. Wire AI_PROVIDER to OpenAI or Anthropic for production; every guarantee above holds the same.

the proof

Verify & tests built in: green.

A starter that looks finished is easy. One that proves it — and keeps proving it while you and your agent build on top — is the whole point. verify.py is the judge, and it ships in the box.

What turns it red

A guardrail that stays on. Break a guarantee — by hand or by agent — and the build goes red.

An agent drops a tenant checkred
A refactor unbalances the ledgerred
A tool lets the agent loop foreverred
Python and Node drift apartred
Someone edits the audit logred

// your agent can't merge a regression past a verifier it must keep green.

What keeps it green

Every guarantee on the left has a test that runs on your machine — across Python, Go & Node. Green means all of them pass, right now, top to bottom. Not a screenshot. Not our word.

verify.py → GREEN
MIT — read & keep every line
Runs offline · no telemetry
Deterministic · reproducible
Verifier ships in the box

Don't believe us. Run it.

Clone the repo and run python verify.py yourself — green in under a minute, on commodity hardware. That's the only proof that counts.

Clone the repo
choose your language

One behavior. Three languages.

The same audited spine in Python, Go and Node — proven to behave identically. Pick the one your team already runs; the verifier holds all three to the same line.

records.py
@router.get("/v1/records")
def list_records(ctx: Ctx) -> Page[Record]:
# tenant scope is enforced, not optional
rows = store.list(owner=ctx.tenant_id, limit=ctx.limit)
return Page(data=rows, next=ctx.cursor)
same request → same response
{
"data": [ { "id": "rec_8x2…", "owner": "ten_4a…" } ],
"next": "eyJpZCI6InJlY184…"
}

Switch the tab — the handler changes, the contract doesn't. That's not something a template or a lucky prompt can fake; it's checked by verify.py on every run.

Read the real handlers

// illustrative snippets — the repo ships the audited originals.

point your agent at it

Code ready for your agent.
Customize and ship your idea.

Paste one prompt. It clones the spine, proves it's green on your machine, and builds on top.

Set up my backend from Gutencode — an audited, agent-ready backend spine (auth, billing, RBAC, an AI/agent runtime + 30+ more domains, all identical in Python, Go & Node, shipped with their own offline verifier).

1. git clone https://github.com/antonibot/gutencode-test && cd gutencode-test
2. Read AGENT.md (the operating law) and .gutencode/contract.json (the route + test map).
3. Run `python verify.py` and confirm it prints GREEN — the whole backend tests and proves itself.
4. Build my product on top of the green baseline (pick python, go, or node). Ship a test with every change and keep verify.py green.
01

Point your agent at the repo

Drop the prompt into Claude Code or Cursor. It reads AGENT.md — the operating law — before it touches anything.

02

It clones it & runs verify.py GREEN

The whole spine tests and proves itself — suites, invariants, parity and durability — on your machine, not in a demo video.

03

You build your product on top

Follow CUSTOMIZE.md and ship the 10% that's actually yours. Every change keeps verify.py green.

Open the repo on GitHub

// it reads AGENT.md + runs verify.py before it builds.

what you get

A SaaS Kit a senior dev would sign off on.

One run prints the same Verified backend spine — production-shaped, audited, reproducible in Python, Go & Node — then hands you the keys to the part that's actually yours: the app layer your agent builds on top.

Deterministic + Verified

Dozens of mechanical audit gates plus per-domain conformance checks run before you ever see the code — and it ships its own offline verify.py so you re-prove it yourself. A red is a real, located bug, not a vibe.

The hard domains, proven

Money, identity and multi-tenancy ship invariant-tested: a ledger that proves debits == credits, auth that proves no-plaintext & deny-by-default, an agent loop that provably terminates.

Green baseline on day 1

Not a skeleton with gaps. The spine is 100% working, audited and unit-tested. Your business logic — the app layer (records, your domain rules) — is what you or your agent build on top, against a green baseline. A CUSTOMIZE guide points at the exact lines.

Swappable adapters

LLM keys, queues, payments, storage — all behind ports. Swap providers from .env. No vendor lock-in, fully offline-testable with fake adapters.

One backend, three languages

Idiomatic, parity-matched code in Python, Go & Node — proven to behave identically across all three. The same spec always prints the same code: byte-for-byte reproducible, every time.

Production-shaped

Clean ports-and-adapters folders, RFC 9457 error envelopes, request IDs + structured logs, and durable SQLite via DATABASE_PATH behind a storage port — swap in your production DB. Restart-durable, proven across all three languages.

the catalog (and growing)

+ auth+ rbac+ multi-tenancy+ ledger+ idempotency+ stripe+ billing+ webhooks+ ai-agent+ search+ notifications+ audit-log+ rate-limit+ oauth+ storage+ health+ auth+ rbac+ multi-tenancy+ ledger+ idempotency+ stripe+ billing+ webhooks+ ai-agent+ search+ notifications+ audit-log+ rate-limit+ oauth+ storage+ health
set expectations

What it is — and what it isn't.
Backend Foundation — not a finished app.

it is

  • A deterministic, Verified backend spine — 35+ audited domains, 3 languages
  • A real GitHub repo you clone, run, and own (MIT)
  • Self-proving: one offline `python verify.py` → GREEN
  • A green baseline your agent customizes on top of

it is not

  • A finished app — the business logic is still yours to add
  • Generated bespoke from your prompt — every run prints the same Kit
  • Your app layer, done (records + your domain rules = your part)
  • A hosted or black-box runtime you rent from us
pricing

Free today. Get it now.

No signup, no subscription. Clone the repos while they're free — pricing may change later, but whatever you take is yours to keep. If it saved you a weekend of boilerplate, buy me lunch.

Free

$0/ right now
  • Watch it print on the site — then read the real repo
  • The full output repo: models, schemas, routes, migrations, tests
  • All 35+ audited domains (auth, rbac, tenancy, ledger, stripe…)
  • Audit-green, unit-tested, durable in Python · Go · Node + a CUSTOMIZE guide
  • Your code, your IP — clone it, it's yours to keep
Get it on GitHub

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support
$39.99/ one-time · no subscription
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Get it on GitHub