06/01/2026
Based on search results, here's the latest information about migrating legacy AI models, with specific context about recent retirements (o3, GPT-4.5, Gemini 2.0 models) and practical migration workflows.
What follows is a a detailed step-by-step guide for researchers, particularly genealogists, created by Perplexity AI. For more information about the latest updates see https://last24zotero.blogspot.com/2026/06/1-june-2026.html
# # Step-by-Step Guide: Migrating Legacy AI Models for Researchers
With OpenAI's o3 retiring August 26, 2026, GPT-4.5 retiring June 27, 2026, and Google's Gemini 2.0 Flash models discontinued today (June 1, 2026), researchers must migrate workflows to avoid service disruptions. This guide provides a structured migration framework applicable to genealogical research, historical analysis, and archival workflows.
# # Phase 1: Audit Your Current AI Dependencies
# # # Identify affected workflows
Document every place you use retiring models:
- **Custom GPTs and Gems** — List all custom assistants built on deprecated models (o3, GPT-4.5, or older Claude/Gemini versions)
- **API integrations** — Review scripts, plugins, or automation tools that call specific model versions
- **Saved prompts and templates** — Catalog prompt libraries, research briefs, and workflow templates optimized for legacy models
- **Project-level configurations** — Check ChatGPT Projects, Claude Projects, or Gemini Gems for hardcoded model references
# # # Map your research workflows to model functions
For each affected workflow, note what the model does:
- Handwriting transcription (pension files, probate records, cemetery registers)
- Document analysis and source extraction (land deeds, census records, wills)
- Research planning and hypothesis generation
- Citation formatting and bibliography generation
- Narrative writing and ancestor biography drafting
# # # Document current performance baselines
Before migrating, capture examples of current output quality:
- Save 3–5 sample prompts with their responses from legacy models
- Screenshot or export particularly successful analyses
- Note which model parameters you use (temperature, max tokens, system prompts)
# # Phase 2: Select Replacement Models
# # # Match tasks to model strengths (June 2026)
Based on recent benchmarks and genealogy-specific testing:
**For handwriting transcription and OCR:**
- **Primary:** Claude Opus 4.8 (4x better error detection, flags uncertain readings)
- **Secondary:** GPT-5.5 Instant (improved context memory for writer-specific patterns)
**For multi-document analysis and cross-referencing:**
- **Primary:** Claude Opus 4.8 (extended reasoning for probate packets, pension files)
- **Secondary:** Gemini 3.5 Flash (fast processing for batch operations)
**For research planning and structured output:**
- **Primary:** GPT-5.5 Instant (conversational memory, template refinement)
- **Secondary:** Claude Sonnet 4.5 (balance of speed and depth)
**For citation and bibliography generation:**
- **Primary:** GPT-5.5 Instant (follows Genealogical Proof Standard formatting reliably)
- **Secondary:** Claude Opus 4.8 (precise source parsing)
# # # Test replacement models with saved examples
Run your Phase 1 sample prompts through candidate replacement models:
1. Use identical prompts on new models
2. Compare output quality, accuracy, and formatting
3. Note any performance differences (speed, token usage, hallucination patterns)
4. Adjust prompts if necessary to match new model strengths
# # Phase 3: Execute the Migration
# # # For ChatGPT Projects and Custom GPTs
**Migrate Custom GPTs from o3 or GPT-4.5 to GPT-5.5 Instant:**
1. Open your Custom GPT in ChatGPT
2. Click "Configure" to access instructions, uploaded files, and capabilities
3. Copy all instructions, conversation starters, and uploaded knowledge files
4. Create a new Custom GPT using GPT-5.5 Instant as the base model
5. Paste instructions and re-upload knowledge files
6. Test with 5–10 representative prompts from your research history
7. Fine-tune instructions based on output differences (GPT-5.5 may need more explicit formatting instructions)
8. Update any shared links or bookmarks to point to the new Custom GPT
**Migrate ChatGPT Projects:**
1. Open the legacy Project
2. Navigate to Project Settings (three dots)
3. Copy all project-level instructions
4. Download all uploaded files (PDFs, GEDCOM files, spreadsheets)
5. Create a new Project with GPT-5.5 Instant as the default model
6. Paste project instructions and re-upload files
7. Review conversation history—if critical context exists, export key threads as markdown and re-upload as reference documents
# # # For Claude Projects (if migrating from older Claude models)
**Upgrade to Claude Opus 4.8 or Sonnet 4.6:**
1. Open your existing Claude Project
2. Click the model selector dropdown
3. Choose Claude Opus 4.8 for complex analysis or Sonnet 4.6 for faster iterations
4. Test with existing Project context—Claude Projects automatically maintain conversation history and uploaded files
5. No file re-upload required; existing knowledge carries forward
# # # For Google Gemini (migrating from Gemini 2.0 Flash models)
**Critical deadline: June 1, 2026:**
1. Update all API calls from `gemini-2.0-flash` or `gemini-2.0-flash-lite` to `gemini-3.5-flash` or `gemini-3.1-flash-lite`
2. For Gemini web interface users, Gems will automatically use the latest models
3. **If using the API:** Change model parameter in your code:
```python
# OLD (fails after June 1, 2026):
model="gemini-2.0-flash"
# NEW:
model="gemini-3.5-flash"
```
4. For OpenAI-compatible endpoints switching to Gemini:
```python
from openai import OpenAI
client = OpenAI(
api_key="your-gemini-api-key",
base_url="https://generativelanguage.googleapis.com/v1beta/openai/"
)
response = client.chat.completions.create(
model="gemini-3.5-flash", # Map from GPT models
messages=[{"role": "user", "content": "Your prompt"}]
)
```
# # # For Perplexity, Grok, and other platforms
Most platforms auto-update to latest models, but verify:
- Check account settings for model version locks
- Review any API integrations for hardcoded model names
- Update bookmarks if model-specific URLs exist
# # Phase 4: Migrate Custom Instructions and Memory
# # # Transfer ChatGPT custom instructions and memory to new models or platforms
**If staying within ChatGPT:**
1. Go to Settings → Personalization → Custom Instructions
2. Copy both "What would you like ChatGPT to know about you?" and "How would you like ChatGPT to respond?"
3. These automatically apply to GPT-5.5 Instant—no action needed if migrating within the same platform
**If migrating ChatGPT → Gemini:**
1. In ChatGPT: Settings → Data Controls → Export Data
2. Download your data archive and extract `chat.html`
3. In Gemini: Create a new Gem
4. Under "Instructions for Gemini," paste your custom instructions from ChatGPT
5. Upload `chat.html` to the Gem's Knowledge section
6. For memories, go to ChatGPT Settings → Personalization → Manage Memories
7. Review each memory—delete outdated or incorrect entries
8. Copy remaining memories one-by-one into Gemini's "Instructions" field (Gemini doesn't have a separate memory system; fold memories into instructions)
**If migrating ChatGPT → Claude:**
1. Export ChatGPT custom instructions and memories as above
2. Claude doesn't have a "memory" feature—incorporate key preferences into your Project instructions or a reference document
3. Upload chat exports as `.txt` or `.md` files to your Claude Project for context
# # # Clean up legacy memories before migration
Review for outdated information:
- Incorrect ancestor dates or places discovered during research
- Old surname spellings you've since corrected
- Deprecated file structures or naming conventions
- Removed research focuses (completed family lines)
# # Phase 5: Update Saved Prompts and Prompt Libraries
# # # Adjust prompts for new model capabilities
**For Claude Opus 4.8 (improved self-correction):**
Add explicit uncertainty requests to prompts:
- **Old prompt:** "Transcribe this 1880 probate document."
- **New prompt:** "Transcribe this 1880 probate document. Flag any words or dates where handwriting is unclear or you're uncertain of accuracy."
**For GPT-5.5 Instant (memory transparency):**
Reference prior research explicitly:
- **Old prompt:** "Analyze this land deed."
- **New prompt:** "Analyze this land deed. Reference my previous research on the Clark family in Creek Nation, and note which prior files or conversations inform your interpretation."
**For Gemini 3.5 Flash (speed optimization):**
Streamline batch prompts:
- **Old prompt:** "Transcribe this cemetery record, then analyze burial patterns, then suggest next research steps."
- **New prompt:** "Transcribe this cemetery record. Output: Name, birth date, death date, plot location." (Submit analysis as a separate, faster query)
# # # Create version-controlled prompt templates
Save prompts in markdown files with metadata:
```markdown
# Probate Extraction Template
**Model:** Claude Opus 4.8
**Updated:** June 1, 2026
**Use case:** Extract structured data from handwritten probate inventories
**Prompt:**
Analyze this probate inventory. Extract:
- Decedent name and death date
- Executor/administrator names
- All property descriptions with appraised values
- Names of heirs and their relationships
- Court and filing date
Flag any uncertain readings or date conflicts.
```
# # Phase 6: Test, Monitor, and Optimize
# # # Run parallel testing during transition period
For 2–4 weeks, run critical workflows on both old and new models:
1. Submit identical prompts to legacy and replacement models
2. Compare outputs for accuracy, completeness, and formatting
3. Document any regressions (tasks the new model performs worse)
4. Adjust prompts or switch models for specific tasks if needed
# # # Monitor for post-migration issues
After full migration:
- Track any increase in hallucinations or formatting errors
- Note if citation accuracy changes
- Monitor token usage and costs (new models may have different pricing)
- Check for changes in processing speed
# # # Build rollback procedures
Until legacy models fully retire:
- Keep access to Custom GPTs built on o3 or GPT-4.5 until August/June retirement dates
- Save `.bak` files of critical prompts and instructions
- Document what worked in legacy models vs. replacements
# # Phase 7: Update Documentation and Training
# # # Revise research guides and workflows
If you teach genealogy workshops or share methods:
1. Update slides, handouts, and blog posts with new model names
2. Replace screenshots showing deprecated models
3. Revise prompt examples to leverage new model features (e.g., Claude Opus 4.8's uncertainty flags)
# # # Train collaborators and research teams
For genealogy societies or research groups:
- Host a migration workshop showing before/after workflows
- Share updated prompt libraries with version notes
- Create troubleshooting guides for common migration issues
# # # Document your migration decisions
Create a log for future reference:
- Which models you chose for which tasks
- Prompt adjustments you made
- Performance differences you observed
- Cost or speed changes
# # Platform-Specific Migration Checklists
# # # ChatGPT (o3 and GPT-4.5 retirement)
- [ ] Export all Custom GPTs' instructions and files
- [ ] Create new Custom GPTs using GPT-5.5 Instant
- [ ] Test with representative prompts
- [ ] Update shared links
- [ ] Copy Project instructions and re-upload files
- [ ] Review and clean ChatGPT Memories
- [ ] Update API calls from `o3` or `gpt-4.5` to `gpt-5.5-instant`
- [ ] Test all integrations (Zapier, Make, custom scripts)
- [ ] Deadline: August 26, 2026 (o3) / June 27, 2026 (GPT-4.5)
# # # Google Gemini (2.0 Flash retirement)
- [ ] Update API calls from `gemini-2.0-flash` to `gemini-3.5-flash`
- [ ] Update API calls from `gemini-2.0-flash-lite` to `gemini-3.1-flash-lite`
- [ ] Test all scripts and integrations
- [ ] Verify Gems are using updated models (automatic for web users)
- [ ] Check for any hardcoded model names in automation tools
- [ ] **Deadline: June 1, 2026** (TODAY—migrations failing after this date)
# # # Anthropic Claude (if upgrading to Opus 4.8)
- [ ] Open existing Projects and switch model to Opus 4.8
- [ ] Test with existing context (files persist automatically)
- [ ] Adjust prompts to request uncertainty flags
- [ ] Update API calls to `claude-opus-4-8` or `claude-sonnet-4-6`
- [ ] No hard deadline (but Opus 4.8 offers significant quality improvements)
# # # Cross-platform migration (ChatGPT → Gemini or Claude)
- [ ] Export ChatGPT data (Settings → Export Data)
- [ ] Extract `chat.html` from archive
- [ ] Copy custom instructions and memories
- [ ] Create new Gem (Gemini) or Project (Claude)
- [ ] Upload chat history and knowledge files
- [ ] Test identity and context retention
- [ ] Update browser bookmarks and shortcuts
- [ ] Notify collaborators of platform change
# # Troubleshooting Common Migration Issues
**Issue:** New model gives different answers to identical prompts
**Solution:** Check if the new model requires more explicit instructions. GPT-5.5 may need formatting examples; Claude Opus 4.8 responds well to "flag uncertainties" requests.
**Issue:** Custom GPT or Gem no longer accesses uploaded files
**Solution:** Re-upload files after migration. File associations don't always transfer when switching base models.
**Issue:** API calls fail with "model not found" errors
**Solution:** Verify exact model name spelling. Use `gpt-5.5-instant`, `claude-opus-4-8`, or `gemini-3.5-flash` (not `GPT-5.5`, `Claude-Opus-4.8`, or `Gemini-3.5-Flash`—casing matters).
**Issue:** Increased costs after migration
**Solution:** Check new model pricing. Opus 4.8 costs $5/$25 per million tokens; GPT-5.5 Instant has different rates than o3. For budget-conscious workflows, use Sonnet 4.6 or Gemini 3.5 Flash instead.
**Issue:** Memories or context seem lost
**Solution:** For ChatGPT, go to Settings → Personalization → Manage Memories and verify they weren't auto-deleted. For cross-platform migrations, manually re-enter key preferences.
# # Post-Migration Best Practices
# # # Maintain a multi-model strategy
Don't rely on a single model:
- Use Claude Opus 4.8 for complex handwriting transcription
- Use GPT-5.5 Instant for research planning and narrative writing
- Use Gemini 3.5 Flash for batch operations and quick lookups
# # # Set up automated model retirement alerts
Create calendar reminders or use tools like Releasebot to monitor deprecation announcements from OpenAI, Anthropic, and Google. Future retirements will follow similar 3–6 month notice periods.
# # # Archive successful workflows
When you find a prompt-model combination that works well:
- Save it in a version-controlled document (markdown or text file)
- Include the model name, date tested, and example outputs
- Share with your research community or genealogy society
# # # Plan for continuous evolution
AI models update every 2–4 weeks in 2026. Build flexibility into your workflows:
- Avoid hardcoding model names where possible
- Use feature-based selection (e.g., "best handwriting model") rather than specific versions
- Test new models quarterly to stay current with improvements
***
**Summary:** Migration is a multi-phase process requiring audit, testing, and documentation. With o3 retiring in 8 weeks, GPT-4.5 in 3.5 weeks, and Gemini 2.0 Flash retired today, researchers should prioritize API updates and Custom GPT migrations immediately. Claude Opus 4.8's improved accuracy and GPT-5.5's memory transparency offer meaningful upgrades worth the transition effort.
The last 72 hours brought significant updates across multiple AI platforms (including model retirements that will impact your previous wo...