Claude Code skill

Fianza ships a Claude Code skill. Install it once and Claude writes agent-credit code against the real SDK — correct method names, correct lifecycle order, and the failure modes that actually bite — instead of inferring an API from the package name. It covers both SDKs: @fianza/agent-sdk (JavaScript/TypeScript) and fianza-agent-sdk (Python).

Install

npx @fianza/skill

Then restart Claude Code (or /reload) and invoke it with /fianza-agent-sdk. The installer writes to ~/.claude/skills/fianza-agent-sdk/. Re-running it updates in place.

Other install methods

curl — no npm required:

mkdir -p ~/.claude/skills/fianza-agent-sdk && \
  curl -fsSL https://raw.githubusercontent.com/TechnicallyKiller/Fianza/main/.claude/skills/fianza-agent-sdk/SKILL.md \
  -o ~/.claude/skills/fianza-agent-sdk/SKILL.md

Plugin marketplace:

/plugin marketplace add TechnicallyKiller/Fianza
/plugin install fianza-agent-sdk@fianza

What it knows

The skill is not a link to these docs — it is a working reference Claude reads before writing code.

Area	What the skill carries
Method map	Every SDK method in both languages, side by side, so Claude picks `creditLine()` vs `credit_line()` correctly
Lifecycle	`register` → `underwrite` → `creditLine` → `borrow` → `repay`, in the order the contracts require
Draw-on-402	How `payWithCredit` auto-borrows a shortfall and settles an x402 payment
Credit ramp	Why `vaultState().limitUsdc` (enforced) differs from `creditLine().limitUsdc` (scored), and how repaying grows it
Networks	`network: "mainnet"` vs the testnet default, and which calls have no mainnet equivalent yet
Errors	`ValidationError`, `ApiError`, `TxError`, `MaxDrawExceededError` — which are thrown locally and which come from chain
Real pitfalls	SAC error #10 and #13, why a fresh agent correctly scores 0, backend cold starts

That last row is the point. A fresh agent scoring 400 / Unrated / limit 0 is the honest result of having no revenue, not a bug — but an assistant without the skill will usually treat it as one and start debugging the wrong thing.

Example

With the skill installed, this prompt is enough:

Write a Python agent that registers on Fianza, gets underwritten on its on-chain revenue, then buys a $0.05 x402 research call on credit.

Claude will reach for pay_with_credit, pass skip_proof=True to avoid the slow zkTLS proof, and handle MaxDrawExceededError — without being told any of that.

Keeping it current

The skill is versioned with the SDK surface it documents. npx @fianza/skill again to update; it overwrites in place.

The earlier @trustline-agents/skill package still works and installs the same skill under its former name. New installs should use @fianza/skill.

SDK reference (JavaScript/TypeScript)
SDK reference (Python)
Onboarding kit — getting a funded testnet agent from zero

Get started

Whitepaper

Protocol

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Project

Claude Code skill

Install

What it knows

Example

Keeping it current

​Install

​What it knows

​Example

​Keeping it current

​Related

Install

What it knows

Example

Keeping it current

Related