Tools & SDKs
Find the payment SDK, proof tools and independent audit verifier in the protocol checkout.
Tools in the repository#
Use the CommonJS SDK for payment accounting and rail lifecycle. Browser crypto and prover clients handle private account operations. FPL tools parse and evaluate questions; independent audit verifiers check exported proof answers.
Examples use repository paths. The docs assume a protocol checkout, not a published npm package or hosted SDK endpoint.
Load the SDK from the protocol checkout and set up its payment ledgers.
Fuyu Policy LanguageWrite account-history questions and check which evidence their answers need.
Independent VerifierVerify an exported audit answer against your own finalized chain history.
Contract TestingRun Solidity tests, choose the suites for your change and reproduce contract artifacts.
Find the tool you need#
| Tool | Location | Use |
|---|---|---|
| Payment modules | sdk/payment-sessions/ | Sessions, subscriptions, authorization, splitters and funding |
| FPL toolchain | dsl/ | Parse and check .fuyu programs, then compile or evaluate them |
| Audit proof relations | circuits/owned-notes/ | Prove facts about owned notes and spend records |
| Independent verifier | apps/privacy/runtime/verify-audit-answer.cjs | Verify an exported answer using independent history |
| Client crypto and proving | apps/privacy/src/crypto/ | Open account keys, decrypt delivery and prepare spends |
Set up the checkout#
Use Node 24, Python 3 and Git LFS. Install lockfile dependencies and fetch the proof files before proving or verifying. The payment SDK uses ethers 5.8.0, and its SQLite worker uses Python's standard-library sqlite3 module.
git lfs pull
npm ci --ignore-scripts
npm ci --prefix apps/privacy --ignore-scripts
# Rebuild circuit sources only when needed:
npm ci --prefix circuits --ignore-scriptsUse Fuyu with an AI assistant#
Give the assistant the current protocol source, SDK reference and deployment manifest. Ask it to use the exported methods and atomic-unit amounts, with providers and funded terms supplied by your application.
For an agent buying services, configure a SessionManager budget and authenticate each signed resource request in your transport. Check contract hashes and required approvals before allowing a broadcast. The SDK has no vendor-specific agent connector.
Keep the deployment files together#
Save the source revision, runtime hashes, proof files and deployment data used by the integration. Dependency installation checks none of those contract identities. Likewise, evaluating a question locally produces a preview; a proof answer still needs verification.
Run contract, circuit and sustained acceptance work on the provisioned Linux environment. Use the development keys on a development deployment; production needs its own key setup.