431 Request Header Fields Too Large

[liu-huitao]

Describe the bug

Local error：

@pt_agentos.js?v=634b0a64:20203 
 GET http://localhost:5173/.vitepress/cache/deps/data:application/wasm;base64,AG…Nlc3NlZC1ieQIGd2FscnVzBjAuMjMuMgx3YXNtLWJpbmRnZW4SMC4yLjk5ICgwNGNhNmYzNGEp 431 (Request Header Fields Too Large)

@pt_agentos.js?v=634b0a64:20160 `WebAssembly.instantiateStreaming` failed because your server does not serve Wasm with `application/wasm` MIME type. Falling back to `WebAssembly.instantiate` which is slower. Original error:
 TypeError: Failed to execute 'compile' on 'WebAssembly': HTTP status code is not ok
@pt_agentos.js?v=634b0a64:21255 Failed to initialize Wasm module: CompileError: WebAssembly.instantiate(): BufferSource argument is empty
    at q4 (@pt_agentos.js?v=634b0a64:20168:30)
    at async d9 (@pt_agentos.js?v=634b0a64:20208:7)
    at async r19 (@pt_agentos.js?v=634b0a64:21253:7)
    at async Promise.all (index 0)
    at async f14 (@pt_agentos.js?v=634b0a64:21259:10)
    at async index.mts:70:9
index.mts:71 Uncaught (in promise) CompileError: WebAssembly.instantiate(): BufferSource argument is empty
    at q4 (@pt_agentos.js?v=634b0a64:20168:30)
    at async d9 (@pt_agentos.js?v=634b0a64:20208:7)
    at async r19 (@pt_agentos.js?v=634b0a64:21253:7)
    at async Promise.all (index 0)
    at async f14 (@pt_agentos.js?v=634b0a64:21259:10)
    at async index.mts:70:9

Stackblitz case error:

See url: https://stackblitz.com/edit/vite-6uhev3lw

Reproduction

1. Open the browser console.
2. Refresh the page

Expected behavior

I hope to solve the issue of Status Code 431 so that Wasm initialization can be successful

System Info

System:
    OS: Windows 10 10.0.19045
    CPU: (8) x64 Intel(R) Core(TM) i7-9700 CPU @ 3.00GHz
    Memory: 2.57 GB / 15.89 GB
  Binaries:
    Node: 20.18.0 - D:\Program Files\nodejs\node.EXE    
    Yarn: 1.22.22 - D:\Program Files\nodejs\yarn.CMD    
    npm: 10.8.2 - D:\Program Files\nodejs\npm.CMD       
    pnpm: 9.13.0 - D:\Program Files\nodejs\pnpm.CMD     
  npmPackages:
    vite: 4.5.3 => 4.5.3
    vue: ^3.4.38 => 3.4.38

Additional context

When adding the following configuration in the config. mjs file, it still doesn't work.

server: {
      headers: {
        maxHeaderSize: "20971520", 
      },
    }

No response

Validations

• Check if you're on the latest VitePress version.
• Follow our Code of Conduct
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.

[brc-dd]

Most likely related to vitejs/vite#8427

new URL("data:application/wasm;base64,...", import.meta.url) is being incorrectly optimized.

If it's a separate package then it can be excluded using optimizeDeps.exclude. If it's not then you'll need to generate/patch the rust_lib.mjs such that it's just "data:application/wasm;base64,..." or if the wasm isn't inlined, then it should be a relative path I think. If patching after build isn't possible then something like this might work:

  vite: {
    plugins: [
      {
        name: 'fix-wasm',
        transform(code, id) {
          if (id.endsWith('.vitepress/theme/pkg/rust_lib.mjs')) {
            return {
              code: code.replace(/new URL\((".*"), import.meta.url\)/, '$1'),
              map: null
            }
          }
        }
      }
    ]
  }

[liu-huitao]

I can confirm that this is indeed a separate package. We're using 'agentos-n' as an external dependency in our project, not as part of our codebase.

We've already implemented the optimizeDeps.exclude approach as you suggested:

optimizeDeps: {
  exclude: ['agentos-n'],
}

However, we're still encountering the issue with the WASM loading. The error occurs specifically when the package attempts to use new URL("data:application/wasm;base64,...", import.meta.url) construction.

Is there a way to apply your suggested plugin solution to an external package like 'agentos-n'? Or would we need to fork and modify the package itself to resolve this issue?
Please refer to the newly modified demo at https://stackblitz.com/edit/vite-6uhev3lw.
Due to the inability to install dependencies online in StackBlitz, I downloaded the demo project to my local computer to modify the code, but I still encountered the error '431 Request Header Fields Too Large', as shown in the supplementary image below.

[brc-dd]

Seems like a bug with vite 5. It works fine with vite 6. (was fixed by vitejs/vite#18163)

Just this works fine:

import { componentPreview, containerPreview } from '@vitepress-demo-preview/plugin'
import { defineConfig } from 'vitepress'

export default defineConfig({
  markdown: {
    config(md) {
      md.use(containerPreview)
      md.use(componentPreview)
    }
  },
  vite: {
    resolve: {
      alias: [
        {
          find: /^vue$/,
          replacement: 'vue/dist/vue.esm-bundler.js'
        }
      ]
    },
    ssr: {
      noExternal: ['vue']
    }
  }
})

import { AntDesignContainer } from '@vitepress-demo-preview/component'
import '@vitepress-demo-preview/component/dist/style.css'
import { createPlugin } from 'agentos-n'
import { Theme } from 'vitepress'
import DefaultTheme from 'vitepress/theme'
import { onMounted } from 'vue'

export default {
  extends: DefaultTheme,
  enhanceApp({ app }) {
    app.component('demo-preview', AntDesignContainer)
  },
  setup() {
    onMounted(async () => {
      await createPlugin()
    })
  }
} satisfies Theme

no need to exclude from optimizeDeps either since it's using inline wasm. In dev there are some warnings regarding sourcemaps but I think they are from that container component. Probably can be ignored.

Change your deps to these, and delete lock file and node_modules and re-run npm install

{
  "private": true,
  "type": "module",
  "scripts": {
    "docs:dev": "vitepress dev docs",
    "docs:build": "vitepress build docs",
    "docs:preview": "vitepress preview docs"
  },
  "devDependencies": {
    "@vitepress-demo-preview/component": "^2.3.2",
    "@vitepress-demo-preview/plugin": "^1.4.0",
    "agentos-n": "^1.0.0",
    "js-base64": "^3.7.7"
    "vitepress": "next",
    "vue": "^3.5.13",
  }
}

[liu-huitao]

Thank you for solving my issue! I really appreciate your help.

I have one additional point to mention: Currently, the line import DefaultTheme from 'vitepress/theme'; in the file node_modules\vitepress\dist\client\app\index.js defaults to reading from docs\.vitepress\theme\index.ts. Is it possible to add support for docs\.vitepress\theme\index.mts as well?

This would provide more flexibility in our project structure and TypeScript module configuration.

[brc-dd]

It should already work - https://stackblitz.com/edit/vite-1uhrsqz4?file=docs/.vitepress/theme/index.mts

[liu-huitao]

I've found that this is supported in "vitepress": "latest", but not in "vitepress": "next". When using the "next" version, we encounter the following error:

[brc-dd]

Seems like some vite bug. I'll try to find/create an issue there.

hmm vitejs/vite#18500

Please track #4644

Seems like resolve.extensions is not properly merged. Workaround:

vite: {
  resolve: {
    extensions: ['.mjs', '.js', '.mts', '.ts', '.jsx', '.tsx', '.json']
  }
}