Diagnose

Diagnose — Debug Extraction Failures

Systematically investigate why an extraction failed or produced poor results. Identify root causes and fix them.

When to Use

• Extraction completed but many pages failed
• Extraction completed but content quality is low
• Extraction hung or crashed mid-way
• The user reports missing content after import

Setup

Ask for or detect:

Phase 1: Triage — What Happened?

Start with liberate_verify — it gives you a structured overview in one call:

• WXR item counts (pages, posts, media)
• Failed URLs and failed media downloads
• Stale CDN URLs still in content
• Quality score breakdown (high/medium/low)
• A "needs attention" summary

This replaces manual log grepping for the initial assessment. If you need more detail, then dig into the raw log:

# Count successes vs failures
grep -c '"type":"processed"' <outputDir>/extraction-log.jsonl
grep -c '"type":"failed"' <outputDir>/extraction-log.jsonl
grep -c '"type":"media_failed"' <outputDir>/extraction-log.jsonl

Classify the problem:

A. High failure rate (>30% failed) Something systematic is wrong — the site is blocking requests, the adapter can't parse the platform, or there's an auth issue.

B. Low failure rate (<30%) with specific pages failing Individual page issues — timeouts, unusual page structures, dynamic content.

C. No failures but low quality content The adapter extracted something but it's the wrong content — nav bars, footers, cookie banners instead of the actual page body.

D. Crash / incomplete extraction The process died mid-way. Check for the lock file, partial WXR, and the last log entry.

E. Missing or incorrect products Products were expected but products.csv is missing, empty, or has wrong data.

Phase 2: Investigate

For high failure rate (Type A):

1. Read the error messages from failed entries:

   grep '"type":"failed"' extraction-log.jsonl | head -5
   

2. Common causes and fixes:

   Error pattern	Cause	Fix
   timeout / AbortError	Site is slow or blocking	Increase --delay, try with browser via --cdp-port
   403 Forbidden	Rate limiting or bot detection	Increase delay, use CDP with a real browser session
   404 Not Found	Stale sitemap, pages moved	Re-run discovery, check if site restructured
   TypeError: fetch failed	Network issue, wrong protocol	Check if site uses http vs https, check DNS
   Navigation failed	Playwright can't load the page	Check if site requires JavaScript, cookies, or auth

3. Probe a failed URL manually:

   curl -sI <failed-url> | head -20
   

   Check: status code, redirects, Content-Type, security headers.

4. Deep browser probe (if the user has Chrome with CDP running): Call liberate_probe with the CDP port and site URL. This connects to the browser and reports:

   • Window globals — platform-specific data objects (GoDaddy W+M: _BLOG_DATA, Shopify: Shopify.*, Squarespace: __NEXT_DATA__, Wix: __WIX_DATA__)
   • Cookies — names, domains, flags (helps diagnose auth/session issues)
   • localStorage — cached config and state
   • Performance API network entries — what API calls the page made (useful when extraction misses data)
   • Platform identity — site IDs, visitor IDs, view mode (helps identify auth context)

   This is especially useful for:

   • Verifying the user is actually logged in (check for session cookies)
   • Finding alternate data sources when API interception fails
   • Understanding why content is empty (check if globals are populated)

5. Check if the platform is detected correctly: call the liberate_detect MCP tool with the site URL (in a dev checkout, npx tsx src/cli.ts inspect <site-url> shows the same detection plus extra probes). If detection is wrong, the wrong adapter is running.

For individual page failures (Type B):

1. Group failures by error type:

   grep '"type":"failed"' extraction-log.jsonl | jq -r .error | sort | uniq -c | sort -rn
   

2. Spot-check the worst offenders — fetch the URL manually and compare against what the adapter tried to do.

3. Check for pattern: Are all failures the same URL type (e.g. all blog posts fail but pages succeed)? This points to a type-specific extraction bug.

For low quality content (Type C):

1. Run /qa to compare WXR content against the origin site. This gives per-page quality grades.

2. Read a few low-scoring pages from the WXR:

   • Is the content just navigation/footer/boilerplate?
   • Is the main content area missing?
   • Are images referenced but missing?

3. Check the adapter's content selector. Each adapter targets specific HTML containers:

   • Wix: extracts from DOM via Playwright
   • Squarespace: ?format=json API or admin API via CDP
   • Webflow: .w-richtext containers
   • Shopify: article or .rte containers
   • GoDaddy W+M: blog posts parse window._BLOG_DATA and convert Draft.js post.fullContent to HTML; pages strip HEADER_SECTION / FOOTER_* / section-title / hero-image widgets from the DOM

   If the site uses a non-standard template, the selector may miss the content.

4. Fetch the origin page and inspect its structure:

   curl -s <page-url> | grep -o '<main\|<article\|class="content\|class="post-body\|class="entry-content' | head -10
   

For crashes (Type D):

1. Check for lock file: .liberation-lock in the output directory means the process didn't clean up.
2. Check the last log entry — this is the page that was being processed when it crashed.
3. Check WXR integrity — if streaming was active, the WXR may be truncated (missing </channel></rss>).
4. Fix and resume: Delete the lock file, then re-run with --resume.

For product issues (Type E):

1. Check if products.csv and products.jsonl exist:

   ls -la <outputDir>/products.csv <outputDir>/products.jsonl
   

2. If both are missing — no products were detected during extraction. Investigate:

   • Were product pages in the sitemap? Check the extraction log for product URLs.
   • Does the site use JSON-LD @type: Product? Fetch a product page and check:

     curl -s <product-url> | grep -o 'application/ld+json' | head -3
     curl -s <product-url> | grep -o '"@type":"Product"'
     

   • If no JSON-LD, the platform may need a custom extractProduct function in its adapter.
   • Were the URLs classified as product type? Check classifyUrl in src/lib/extraction/sitemap.ts for the URL patterns it recognizes.

3. If products.jsonl exists but products.csv is missing or empty — the JSONL→CSV conversion failed. Read products.jsonl to check data quality:

   head -3 <outputDir>/products.jsonl | jq .
   

   Check: do products have names? Prices? Are fields malformed?

4. If products.csv exists but data is wrong:

   • Missing prices — the JSON-LD offers array may be structured differently than expected. Fetch a product page and inspect the JSON-LD.
   • Missing images — check if images are in ld.image as strings, objects with .url, or in a different field.
   • Missing variants — the generic JSON-LD extractor only produces simple products. Variants require platform-specific extraction (Shopify and Wix have this; other platforms may need it added via /adapt).
   • Duplicate products — if both the adapter's custom extractor and the shared JSON-LD extractor fire for the same page, products may be doubled. Check if extractProduct is passed to runExtractionLoop alongside the generic fallback.

5. Check product count vs expectations:

   wc -l <outputDir>/products.jsonl
   grep -c '"type":"product"' <outputDir>/extraction-log.jsonl || echo "no product type in log"
   

Phase 3: Fix

Based on the diagnosis:

Adapter-level fixes

If the content selector is wrong for this site's template:

1. Read the adapter's extractPage function
2. Identify the correct content container
3. Add a fallback selector or adjust the existing one
4. Re-extract affected pages with --resume

Configuration fixes

If the issue is rate limiting, timeouts, or auth:

1. Suggest the right --delay value
2. Suggest using --cdp-port with an authenticated browser session
3. Suggest providing a --token if the platform supports API keys

Data fixes

If the WXR has issues but re-extraction isn't needed:

1. Use /qa to identify and patch specific content gaps
2. Manually fix truncated WXR (add closing tags)

Phase 4: Verify

After applying fixes:

1. Re-extract with --resume (only re-processes failed URLs)
2. Run /qa to check content quality
3. Compare failure counts before and after

Phase 5: Document

If you discovered a platform-specific issue or workaround:

1. Add a DISCOVERIES.md entry
2. If the fix is adapter code, commit it with a descriptive message

Common Diagnostic Commands

# Overview of extraction results
wc -l <outputDir>/extraction-log.jsonl
grep -c '"processed"' <outputDir>/extraction-log.jsonl
grep -c '"failed"' <outputDir>/extraction-log.jsonl

# Most common errors
grep '"failed"' <outputDir>/extraction-log.jsonl | grep -o '"error":"[^"]*"' | sort | uniq -c | sort -rn

# Slowest pages
grep '"processed"' <outputDir>/extraction-log.jsonl | grep -o '"durationMs":[0-9]*' | sort -t: -k2 -rn | head -10

# Check WXR size and item count
wc -c <outputDir>/output.wxr
grep -c '<item>' <outputDir>/output.wxr

# Check media downloads
ls <outputDir>/media/ | wc -l
grep -c '"media_failed"' <outputDir>/extraction-log.jsonl

# Check if extraction is complete
test -f <outputDir>/.discovery-complete && echo "Complete" || echo "Incomplete"

# Product diagnostics
wc -l <outputDir>/products.jsonl 2>/dev/null || echo "No products.jsonl"
wc -l <outputDir>/products.csv 2>/dev/null || echo "No products.csv"
head -3 <outputDir>/products.jsonl 2>/dev/null | python3 -m json.tool 2>/dev/null || true

Important Rules

1. Read the logs first. The extraction log tells you exactly what happened — don't guess.
2. Probe before fixing. Understand the root cause before changing code.
3. One fix at a time. Change one thing, re-test, confirm it helped.
4. Don't mask failures. If a page genuinely can't be extracted, that's information — don't silence the error.
5. Document what you find. Platform quirks discovered during diagnosis are valuable for DISCOVERIES.md.