shieldkit

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shieldkitProduction guardrails for the Vercel AI SDK

Input/output safety, structured output repair, cost budgets, audit logging, and tool policies — verified with 163 automated tests

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Run the demo
npm
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🛡️

Input guardrails

Prompt injection, PII redaction, keyword deny lists — with homoglyph and zero-width normalization since v0.2.0

🔁

Structured output repair

JSON repair and Zod schema validation with automatic retries on `generateText` and `streamText`

💰

Cost tracking

Per-session token and USD budgets with pre-call estimates and warn thresholds

📋

Audit logging

Structured lifecycle events (`guard.triggered`, `request.blocked`, `repair.success`) to console or custom sinks

🔧

Tool guards

Allow/deny lists, call limits, and approval gates via `guardTools`

✅

Verified

163 tests in CI, adversarial corpus, red team harness, and `npm run demo` with 31 PASS/FAIL checks

New in v0.2.0 ​

  • Evasion hardening — normalizeGuardText() strips zero-width characters and folds Cyrillic homoglyphs before injection and keyword guards
  • Interactive demo — npm run demo runs a 9-section tour with 31 automated checks and audit evidence (mock + optional Ollama)
  • Release automation — tagging v* publishes to npm and creates a GitHub Release from CHANGELOG.md

Read the changelog on GitHub · Input guardrails docs · npm publishing

Try it locally ​

bash
git clone https://github.com/sakurablush/shieldkit.git
cd shieldkit && npm ci && npm run demo

Sections 1–8 use mocks only; section 9 needs Ollama. Expect Demo summary — 31/31 checks passed.

ts
import { generateText } from 'ai';
import { shield } from 'shieldkit';

const model = shield(yourModel, { mode: 'balanced' });

await generateText({
  model,
  prompt: 'Hello',
  providerOptions: { aiShield: { sessionId: 'user-123' } },
});

Documentation map ​

SectionLink
Getting startedInstall and first request
ArchitectureMiddleware chain
FeaturesGuards, repair, cost, audit, tools
TestingRunning tests · Verification matrix
ExamplesRunnable scripts
APIPublic exports
ContributingDevelopment guide · Cursor skills