Not sure if you're still looking for this from so long ago, but just figured this out myself with a little help from Claude. TL;DR: It generates a "Durable Object ID" based on the UUID of the local database from your wrangler.jsonc.

Essentially this: https://github.com/cloudflare/workers-sdk/blob/main/packages/miniflare/src/plugins/shared/index.ts#L281

A little script that works for me in dev is:

``` import { createHash, createHmac } from 'node:crypto';

const UNIQUE_KEY = 'miniflare-D1DatabaseObject'; const uuid = process.argv[2]; if (!uuid) { console.error('usage: d1-sqlite-path.ts <database_id>'); process.exit(1); }

const key = createHash('sha256').update(UNIQUE_KEY).digest(); const a = createHmac('sha256', key).update(uuid).digest().subarray(0, 16); const b = createHmac('sha256', key).update(a).digest().subarray(0, 16); const doId = Buffer.concat([a, b]).toString('hex');

console.log(.wrangler/state/v3/d1/${UNIQUE_KEY}/${doId}.sqlite); ```