Developer playground

Your sandbox awaits

Agent-friendly CLI, 31 public primitives, Swagger at runtime, and a library layer designed so new rails and providers don't rewrite the world. Early access for people who will actually call the API.

Quickstart API surface GitHub

Quickstart

Run the protocol locally

Starts with zero credentials (memory ledger, deterministic settlement). Add .env keys to unlock Plaid, Coinbase CDP, Base mainnet, and Sheets.

# clone & install
git clone https://github.com/enkayxyz/k-0.git && cd k-0
python3 -m pip install -r modules/protocol/requirements.txt

# API
python3 -m uvicorn src.main:app --app-dir modules/protocol \
  --host 127.0.0.1 --port 8000

# Swagger · readiness
open http://127.0.0.1:8000/docs
open http://127.0.0.1:8000/uat/readiness

# k0 CLI — every primitive is a subcommand
python3 modules/protocol/cli/k0.py onboard \
  --email [email protected]
python3 modules/protocol/cli/k0.py link-bank
python3 modules/protocol/cli/k0.py pay \
  --to [email protected] --amount 10
python3 modules/protocol/cli/k0.py corridor-pay \
  --to [email protected] --amount 10 --corridor us-us

# agent-friendly JSON on every command
python3 modules/protocol/cli/k0.py status --json

Demo ./scripts/launch_demo.sh Probe ./scripts/chain_probe.sh Tests 237 passing (unit/contract/library)

S-primitives

31 public endpoints by domain

Each S-primitive is a thin orchestration layer: validate → authorize → compose W-libraries → return. One file per endpoint under modules/protocol/src/api/.

Auth & onboarding

S1 authenticate
S15 validate-otp
S23 recover-account
S28 onboard
S29 bootstrap-app

Bank & KYC

S3 link-bank
S4 submit-kyc
S10 verify-payee

Payments

S5 fee-estimate
S6 check-fee-balance
S7 approve-fees
S8 send-payment
S30 initiate-payment
S31 corridor-payment
S25 bulk-send

Payees & accounts

S9 create-payee
S13 block-payee
S19 payees
S2 create-account
S17 balance
S18 history
S26 set-default
S27 list-accounts

Compliance & audit

S11 attach-evidence
S12 anchor-contract
S14 stop-journey
S16 audit-sync
S20 logs
S21 idempotency
S22 compliance-note

Design note

Centralized processor endpoints that imply K0 holds funds or issues stablecoins (e.g. mint treasury APIs) are not part of the protocol surface — they conflict with the no-intermediary principle. Compare against Circle/M0-style models only as conceptual contrast.

CLI & agents

k0 — the agent interface

Every primitive as a subcommand with --json, plus a REPL. Built for humans and coding agents in the same loop.

User flows

onboard · auth · link-bank · accounts · balance · payee · quote · send · pay · claims

Money edges

onramp · offramp · corridor-pay · ledger · logs · status · chains

Admin

verify-payee · reverse · sweep-expired — KYC gate and escrow ops for pilots

Repository map

Where things live

Path	What it is
`modules/protocol/src/api/`	S-primitives — one file per public endpoint
`modules/protocol/src/library/`	W-libraries — W1 through W25
`modules/protocol/src/service.py`	Fee engine, idempotency, escrow state machine
`modules/protocol/cli/k0.py`	CLI + REPL
`modules/protocol/tests/`	Unit + contract + library tests
`docs/ARCHITECTURE.md`	Protocol design, payment flows, seams
`docs/requirements/01-Current/`	Product & engineering requirements SSOT
`modules/marketing/`	Launch sites (this folder is launch v002)

Build on K0

Ship a P2P transfer path

Start with onboard → fee estimate → initiate-payment. For corridor experiments, use S31 with us-us or us-in. Readiness endpoint shows which integrations are live in your environment.

Protocol Intro Source Early access form

Integration checklist

Run API with zero credentials
Hit /docs and /uat/readiness
Onboard two emails via CLI
Pay between them (ledger path)
Add Plaid / EVM keys for live rails
Corridor pilot with claim/escrow path