feat(artifacts): download artifacts from pse CDN

.changeset/great-eggs-unite.md

@@ -0,0 +1,5 @@
+---
+"@zk-kit/artifacts": minor
+---
+
+download artifacts from https://snark-artifacts.pse.dev

packages/artifacts/src/download/download.ts

@@ -1,18 +1,9 @@
 import { createWriteStream, existsSync } from 'node:fs'
 import { mkdir } from 'node:fs/promises'
 import { dirname } from 'node:path'
-import type { Urls } from './urls.ts'
 
-async function fetchRetry(urls: string[]): Promise<ReturnType<typeof fetch>> {
-  const [url] = urls
-  if (!url) throw new Error('No urls to try')
-  return fetch(url).catch(() => fetchRetry(urls.slice(1)))
-}
-
-export async function download(urls: Urls | string[] | string, outputPath: string) {
-  const { body, ok, statusText, url } = Array.isArray(urls)
-    ? await fetchRetry(urls as string[])
-    : await fetch(urls as string)
+export async function download(url: string, outputPath: string) {
+  const { body, ok, statusText } = await fetch(url)
   if (!ok)
     throw new Error(`Failed to fetch ${url}: ${statusText}`)
   if (!body) throw new Error('Failed to get response body')
@@ -42,7 +33,7 @@ export async function download(urls: Urls | string[] | string, outputPath: strin
   }
 }
 
-export async function maybeDownload(urls: Urls | string[] | string, outputPath: string) {
-  if (!existsSync(outputPath)) await download(urls, outputPath)
+export async function maybeDownload(url: string, outputPath: string) {
+  if (!existsSync(outputPath)) await download(url, outputPath)
   return outputPath
 }

packages/artifacts/src/download/index.browser.ts

@@ -1,15 +1,26 @@
-import type { SnarkArtifacts } from './types'
-import { getSnarkArtifactUrls } from './urls'
+import { type Project, projects } from '../projects'
+import type { SnarkArtifacts, Version } from './types'
+import { getBaseUrl } from './urls'
 
-// TODO: retry for browser?
-// beisdes, is caching already handled by circom/snarkjs?
 export default async function maybeGetSnarkArtifacts(
-  ...pars: Parameters<typeof getSnarkArtifactUrls>
+  project: Project,
+  options: {
+    parameters?: (bigint | number | string)[]
+    version?: Version
+    cdnUrl?: string
+  } = {},
 ): Promise<SnarkArtifacts> {
-  const { wasms, zkeys } = await getSnarkArtifactUrls(...pars)
+  if (!projects.includes(project))
+    throw new Error(`Project '${project}' is not supported`)
+
+  options.version ??= 'latest'
+  const url = await getBaseUrl(project, options.version)
+  const parameters = options.parameters
+    ? `-${options.parameters.join('-')}`
+    : ''
 
   return {
-    wasm: wasms[0],
-    zkey: zkeys[0],
+    wasm: `${url}${parameters}.wasm`,
+    zkey: `${url}${parameters}.zkey`,
   }
 }

packages/artifacts/src/download/index.node.ts

@@ -1,10 +1,9 @@
 import { tmpdir } from 'node:os'
 import { maybeDownload } from './download.ts'
+import _maybeGetSnarkArtifacts from './index.browser.ts'
 import type { SnarkArtifacts } from './types'
-import { getSnarkArtifactUrls } from './urls'
 
-// https://unpkg.com/@zk-kit/poseidon-artifacts@latest/poseidon.wasm -> @zk/poseidon-artifacts@latest/poseidon.wasm
-const extractEndPath = (url: string) => url.substring(url.indexOf('@zk'))
+const extractEndPath = (url: string) => url.split('pse.dev/')[1]
 
 /**
  * Downloads SNARK artifacts (`wasm` and `zkey`) files if not already present in OS tmp folder.
@@ -18,17 +17,17 @@ const extractEndPath = (url: string) => url.substring(url.indexOf('@zk'))
  * @returns {@link SnarkArtifacts}
  */
 export default async function maybeGetSnarkArtifacts(
-  ...pars: Parameters<typeof getSnarkArtifactUrls>
+  ...pars: Parameters<typeof _maybeGetSnarkArtifacts>
 ): Promise<SnarkArtifacts> {
-  const { wasms, zkeys } = await getSnarkArtifactUrls(
+  const urls = await _maybeGetSnarkArtifacts(
     ...pars,
   )
 
-  const outputPath = `${tmpdir()}/${extractEndPath(wasms[0])}`
+  const outputPath = `${tmpdir()}/snark-artifacts/${extractEndPath(urls.wasm)}`
 
   const [wasm, zkey] = await Promise.all([
-    maybeDownload(wasms, outputPath),
-    maybeDownload(zkeys, outputPath.replace(/.wasm$/, '.zkey')),
+    maybeDownload(urls.wasm, outputPath),
+    maybeDownload(urls.zkey, outputPath.replace(/.wasm$/, '.zkey')),
   ])
 
   return {

packages/artifacts/src/download/types.ts

@@ -5,10 +5,6 @@
  */
 export type SnarkArtifacts = Record<'wasm' | 'zkey', string>
 
-// Recursively build an array type of length L with elements of type T.
-export type ArrayOf<T, L extends number, A extends unknown[] = []> = A['length'] extends L ? A
-  : ArrayOf<T, L, [T, ...A]>
-
 type Digit = `${number}`
 type PreRelease = 'alpha' | 'beta'
 

packages/artifacts/src/download/urls.ts

@@ -1,7 +1,7 @@
-import { type Project, projects } from '../projects'
-import type { ArrayOf, Version } from './types'
+import type { Project } from '../projects'
+import type { Version } from './types'
 
-export type Urls = ArrayOf<string, 3>
+const BASE_URL = 'https://snark-artifacts.pse.dev'
 
 export async function getAvailableVersions(project: Project) {
   const res = await fetch(`https://registry.npmjs.org/@zk-kit/${project}-artifacts`)
@@ -15,35 +15,7 @@ async function isVersionAvailableOrThrow(project: Project, version: Version) {
     throw new Error(`Version '${version}' is not available for project '${project}'`)
 }
 
-export async function getBaseUrls(project: Project, version: Version): Promise<Urls> {
+export async function getBaseUrl(project: Project, version: Version): Promise<string> {
   await isVersionAvailableOrThrow(project, version)
-  return [
-    `https://unpkg.com/@zk-kit/${project}-artifacts@${version}/${project}`,
-    `https://raw.githubusercontent.com/privacy-scaling-explorations/snark-artifacts/@zk-kit/${project}-artifacts@${version}/packages/${project}/${project}`,
-    `https://cdn.jsdelivr.net/npm/@zk-kit/${project}-artifacts@${version}/${project}`,
-  ]
-}
-
-export async function getSnarkArtifactUrls(
-  project: Project,
-  options: {
-    parameters?: (bigint | number | string)[]
-    version?: Version
-    cdnUrl?: string
-  } = {},
-) {
-  if (!projects.includes(project))
-    throw new Error(`Project '${project}' is not supported`)
-
-  options.version ??= 'latest'
-  const urls = await getBaseUrls(project, options.version)
-
-  const parameters = options.parameters
-    ? `-${options.parameters.join('-')}`
-    : ''
-
-  return {
-    wasms: urls.map((url) => `${url}${parameters}.wasm`) as unknown as Urls,
-    zkeys: urls.map(url => `${url}${parameters}.zkey`) as unknown as Urls,
-  }
+  return `${BASE_URL}/${project}/${version}/${project}`
 }