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Built for real engineering decisions

AI Model & API Guides

Source-linked guidance for AI models, API integration, and developer workflows—turning fast-changing prices, quotas, capabilities, and limits into decisions you can verify.
  • Primary sources first
  • Reproducible steps and failure boundaries
  • Volatile facts carry review dates
  • 482 articles
  • 6 languages
  • 12 topics
  • Updated Oct 7, 2026

An agent execution checkpoint blocks new calls, preserves validated work, and separates uncertain writes for reconciliation.
LatestAPI Guides

How to Stop an AI Agent Tool Loop—and Keep It Stopped

Stop new tool execution, preserve verified results, and reconcile any uncertain write before resuming. A turn limit contains a loop; progress checks and operation records make recovery safer.

12 min
Diagram connecting application JSON and YAML to an image API request, with a separate PDF document-processing step
API Guides

Nano Banana Pro API Guide: JSON, YAML, Image Saving, and PDFs

Call gemini-3-pro-image through Google Interactions, save image bytes from the full response, and compile your own JSON or YAML job settings. PDFs need a document-capable model before Pro receives the verified facts and page images.

12 min
Pro image access differs across Gemini Apps, AI Mode, and native API, followed by separate response-feedback checks.
Troubleshooting

Nano Banana Pro `RESTRICTED by System Instructions`? Check the Gate First

If Pro returns a restriction message or no image, first recover the correct Pro route: More → Redo with Pro in Gemini, the Pro menu in eligible AI Mode accounts, or gemini-3-pro-image in the API. Then check the actual response before calling the failure a policy block.

10 min
Gemini image references can use supported HTTPS, inline bytes, or upload URIs after checking the actual outgoing value.
Troubleshooting

Nano Banana Pro "Unsupported File URI Type"? Fix the Gemini File Route

For "Unsupported file URI type," check the exact image value your app sent and the endpoint that rejected it. Native Gemini can accept supported HTTPS URLs; local paths, unresolved templates and base64 data URLs need a different payload. Verify the repair by getting an edited image from the same Pro request.

11 min
Codex token-exchange 403: read the full error, preserve response details, distinguish an unexplained refusal from a country, account or workspace restriction, and check the actual Codex host
Developer Tools & Agents

Codex Token Exchange Failed 403: Diagnose and Recover Sign-In

A Codex token-exchange 403 is a refused authentication request. The full error tells you whether to repair callback access, check the client’s network, renew stored credentials, or stop for an access restriction.

11 min