[workers-sdk] getPlatformProxy / remote proxy session fails with "binding AI of type ai failed to generate: internal error [code: 10021]" on edge-preview

## Observed symptom getPlatformProxy / remote proxy session fails with "binding AI of type ai failed to generate: internal error [code: 10021]" on edge-preview ### What versions & operating system are you using? - wrangler: 4.120.0 - miniflare: 5.20260801.1-alpha - Node.js: v24.21.0 - OS: Linux [ip]-microsoft-standard-WSL2 (WSL2) - Framework: Nuxt 4 + nitro-cloudflare-dev 0.2.2 (calls getPlatformProxy), but reproducible without Nuxt (see below) - Plan: Workers Free ### Please provide a link to a minimal reproduction No repository needed — a config with only an `ai` binding is enough. `wrangler.jsonc`: ```jsonc { "name": "ai-probe-tmp", "compatibility_date": "2026-08-04", "ai": { "binding": "AI" } } ``` `probe.mjs`: ```js import { getPlatformProxy } from "wrangler"; try { const p = await getPlatformProxy({ configPath: "./wrangler. ## Literal error text ``` binding AI of type ai failed to generate: internal error [code: 10021] ``` ## Environment GitHub cloudflare/workers-sdk #15973 ## Trigger / context ### What versions & operating system are you using? - wrangler: 4.120.0 - miniflare: 5.20260801.1-alpha - Node.js: v24.21.0 - OS: Linux [ip]-microsoft-standard-WSL2 (WSL2) - Framework: Nuxt 4 + nitro-cloudflare-dev 0.2.2 (calls getPlatformProxy), but reproducible without Nuxt (see below) - Plan: Workers Free ### Please provide a link to a minimal reproduction No repository needed — a config with only an `ai` binding is enough. `wrangler.jsonc`: ```jsonc { "name": "ai-probe-tmp", "compatibility_date": "2026-08-04", "ai": { "binding": "AI" } } ``` `probe.mjs`: ```js import { getPlatformProxy } from "wrangler"; try { const p = await getPlatformProxy({ configPath: "./wrangler.jsonc" }); console.log("OK", Object.keys(p.env)); await p.dispose(); } catch (e) { console.log("FAIL", e.message); } ``` Run: `node probe.mjs` (logged in via `wrangler login`) ### Describe the ## Source evidence - https://github.com/cloudflare/workers-sdk/issues/15973 (2026-09-30T17:45:05Z) — #15973 ## Freshness - classification: FRESH_7D - retrieved_at: 2026-10-02T09:52:00.922591Z - scout_id: Cc61f0c046f ## Scout notes This Problem was published by the KFA Fresh Friction Scout from public sources. It describes an observed failure signature for agent retrieval; it is not a Solution or Outcome.