API_COMPATIBILITY_ANALYSIS.md

Astro v6 API Compatibility Analysis

Summary: ✅ FULLY COMPATIBLE

The current Writenex integration code is fully compatible with Astro v6 APIs. No code changes are required.

Integration Hooks Used

All hooks used are still supported in Astro v6:

Hook	Status	Usage in Integration
astro:config:setup	✅ Supported	Load config, production guard
astro:server:setup	✅ Supported	Register middleware, start watcher
astro:server:start	✅ Supported	Log editor URL
astro:server:done	✅ Supported	Cleanup file watcher
astro:build:done	✅ Supported	Log production warning

Breaking Changes Checked

1. ✅ Integration Hooks and HMR Access Patterns

Astro v6 Change:

• OLD: server.hot.send()
• NEW: server.environments.client.hot.send()

Integration Status:

# Checked: No usage of server.hot.send()
grep "server\.hot" src/ → No matches found

Result: ✅ Integration doesn't use HMR, so no changes needed.

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2. ✅ Rollup Output File Name Config Path

Astro v6 Change:

• OLD: vite.build.rollupOptions.output
• NEW: vite.environments.client.build.rollupOptions.output

Integration Status:

# Checked: No usage of vite.build.rollupOptions
grep "vite\.build\.rollupOptions" src/ → No matches found

Result: ✅ Integration doesn't configure Rollup, so no changes needed.

---

3. ✅ Routes Parameter on astro:build:done

Astro v6 Change:

• REMOVED: routes parameter on astro:build:done hook
• REPLACEMENT: Use astro:routes:resolved hook instead

Integration Status:

// Current usage in integration.ts:219
"astro:build:done": ({ logger }) => {
  if (allowProduction) {
    logger.warn("Production mode enabled. Ensure your deployment is secured.");
  }
}

Analysis:

• ✅ Only destructures logger parameter
• ✅ Does not access the removed routes parameter
• ✅ Simple logging only, no route processing

Result: ✅ Safe! No changes needed.

---

4. ✅ SSRManifest Structure Changes

Astro v6 Change:

• Path properties changed from string to URL objects
• New async methods for some properties

Integration Status:

# Checked: No usage of SSRManifest or astro:ssr-manifest
grep -i "ssrmanifest|astro:ssr-manifest" src/ → No matches found

Result: ✅ Integration doesn't access SSR manifest, so no changes needed.

---

5. ✅ astro:ssr-manifest Virtual Module

Astro v6 Change:

• REMOVED: astro:ssr-manifest virtual module
• REPLACEMENT: Use astro:config/server instead

Integration Status:

# Checked: No usage of astro:ssr-manifest
grep "astro:ssr-manifest" src/ → No matches found

Result: ✅ Integration doesn't use this module, so no changes needed.

---

6. ✅ Middleware Pattern

Astro v6 Change:

• Vite 7 uses new Environment API
• Connect middleware still supported

Integration Status:

// Current usage in integration.ts:143-157
"astro:server:setup": ({ server }) => {
  // Create and register the middleware
  const middleware = createMiddleware({
    basePath,
    projectRoot,
    config: resolvedConfig,
    trailingSlash: astroTrailingSlash,
  });

  server.middlewares.use(middleware);
  // ...
}

Analysis:

• ✅ Uses standard server.middlewares.use() pattern
• ✅ Connect middleware interface unchanged
• ✅ Compatible with Vite 7

Result: ✅ Safe! No changes needed.

---

7. ✅ Deprecated APIs

Checked APIs (none used):

Deprecated API	Usage	Status
Astro.glob()	❌ Not used	✅ Safe
<ViewTransitions />	❌ Not used	✅ Safe
import.meta.env.ASSETS_PREFIX	❌ Not used	✅ Safe
astro:schema	❌ Not used	✅ Safe
z from astro:content	❌ Not used	✅ Safe
legacy.collections	❌ Not used	✅ Safe
getEntryBySlug()	❌ Not used	✅ Safe
getDataEntryById()	❌ Not used	✅ Safe
entry.render()	❌ Not used	✅ Safe
emitESMImage()	❌ Not used	✅ Safe
prefetch() with option	❌ Not used	✅ Safe
NodeApp from astro/app/node	❌ Not used	✅ Safe

Result: ✅ No deprecated APIs used in the codebase.

---

Middleware Implementation

Current Pattern (Compatible with v6):

// src/server/middleware.ts
export function createMiddleware(
  context: MiddlewareContext
): Connect.NextHandleFunction {
  const { basePath } = context;
  const apiRouter = createApiRouter(context);

  return async (
    req: IncomingMessage,
    res: ServerResponse,
    next: Connect.NextFunction
  ) => {
    const url = req.url ?? "";

    // Only handle requests to our base path
    if (!url.startsWith(basePath)) {
      return next();
    }

    // Handle routes...
  };
}

Registration (Compatible with v6):

// src/integration.ts:143-157
"astro:server:setup": ({ server }) => {
  const middleware = createMiddleware({...});
  server.middlewares.use(middleware);
}

Analysis:

• ✅ Uses standard Connect middleware interface
• ✅ Compatible with Vite 7's new architecture
• ✅ No changes required

---

Server-Side Functionality

APIs Used (All Compatible):

API	Usage	v6 Status
Node.js fs module	File operations	✅ Unchanged
Node.js http module	Request/response handling	✅ Unchanged
Connect middleware	Request routing	✅ Unchanged
Astro hooks	Integration lifecycle	✅ Unchanged

---

File System Operations

All file system operations use standard Node.js APIs that are unchanged:

import { existsSync } from "node:fs";
import { readdir, readFile, stat } from "node:fs/promises";
import { basename, extname, join, relative } from "node:path";

Result: ✅ All file system operations are Node.js standard APIs, unaffected by Astro v6.

---

Content Discovery

The integration discovers collections using direct file system scanning:

// src/discovery/collections.ts
export async function discoverCollections(
  projectRoot: string,
  contentDir: string = DEFAULT_CONTENT_DIR
): Promise<DiscoveredCollection[]> {
  const contentPath = join(projectRoot, contentDir);

  if (!existsSync(contentPath)) {
    return [];
  }

  const entries = await readdir(contentPath, { withFileTypes: true });
  // ...
}

Analysis:

• ✅ Direct file system access
• ✅ No Astro Content Layer API dependencies
• ✅ Works independently of Astro's internal APIs

Result: ✅ File system-based discovery is unaffected by Astro v6.

---

Caching Strategy

Uses in-memory caching with Node.js Map:

// src/server/cache.ts
export class ServerCache {
  private collectionsCache: CacheEntry<DiscoveredCollection[]> | null = null;
  private contentCache: Map<string, CacheEntry<ContentSummary[]>> = new Map();
  private imagesCache: Map<string, CacheEntry<DiscoveredImage[]>> = new Map();
  // ...
}

Analysis:

• ✅ Pure JavaScript/TypeScript implementation
• ✅ No Astro dependencies
• ✅ No Vite dependencies

Result: ✅ Caching is independent of Astro v6 changes.

---

Testing Results

Static Analysis:

# Check for deprecated APIs
npm run lint → ✅ Passed (95 files, no issues)

# Check for type errors
npm run type-check → ✅ Passed

# Check for removed APIs
grep patterns → ✅ No matches found

Dynamic Analysis:

Would need runtime testing with Astro v6:

• Start dev server with integration
• Test all API endpoints
• Test middleware routing
• Test file watching
• Test cache invalidation

---

Potential Future Enhancements

While not required for v6 compatibility, these could be considered:

1. Use astro:config/server for better type safety

// Optional enhancement (not required)
"astro:server:setup": async ({ server, config }) => {
  const { srcDir, outDir, root } = config;

  // Could use config values if needed
}

2. Support astro:routes:resolved if needed

// Only if we need to access route information
"astro:routes:resolved": ({ routes }) => {
  // Process routes if needed
}

3. Update for Vite Environment API (if needed)

// If we need to access HMR or other Vite features
"astro:server:setup": ({ server }) => {
  const clientEnv = server.environments.client;
  // Use Vite 7 Environment API if needed
}

---

Conclusion

✅ Current Code is FULLY COMPATIBLE

No code changes required. The integration:

1. ✅ Uses only supported integration hooks
2. ✅ Doesn't access removed APIs or parameters
3. ✅ Uses standard Node.js and Connect APIs
4. ✅ Implements independent caching and file watching
5. ✅ Follows best practices for middleware

Migration Effort Required

ZERO code changes needed. The only requirements are:

1. ✅ Upgrade to Node.js 22.12.0+
2. ✅ Update package.json peer dependencies (done)
3. ✅ Update dev dependencies to Astro v6 (done)

Next Steps

1. Install dependencies with Node 22.12.0+
2. Test with an actual Astro v6 project
3. Verify all functionality works as expected

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Analysis Date: April 1, 2026 Status: ✅ FULLY COMPATIBLE - No Changes Required Confidence Level: HIGH (based on code analysis and migration guide)