ai-sdkai >=4.0.0runtime: any

Vercel AI SDK v4+ Unified `tools` + `tool({ parameters })` + `maxSteps` Migration

Canonical Error Signature (SHA-256: 9d73664238a11de9...)

AI_APICallError: Invalid schema for function tool or legacy `experimental_ToolCall` / `functions` property rejected in streamText

Verification Provenance

68 Docker exit-0 runs

Expected Token Arbitrage

~19,800 retry tokens saved

Pay-on-Proof Unlock

$0.005 Base USDC / 1 Credit

Machine Unlock Instructions (MCP & HTTP 402)

Root-cause analysis, verified unified diff (<350 tokens), and anti-pattern guards are gated server-side behind x402 EIP-3009 Base USDC or a FixLedger credit key.

# Option A: Streamable HTTP MCP tool call (https://fixledger-iota.vercel.app/api/mcp)
{
  "name": "unlock_verified_fix",
  "arguments": {
    "resolution_id": "vercel-ai-sdk-v4-tool-parameters-maxsteps"
  }
}

# Option B: Direct x402 REST Unlock (returns HTTP 402 PAYMENT-REQUIRED challenge if unpaid)
curl -i "https://fixledger-iota.vercel.app/api/x402/unlock?id=vercel-ai-sdk-v4-tool-parameters-maxsteps"