Blog

API Integration

Qwen3.8 Flash API Integration: Model ID, Protocol and Billing Checks

Evaluate Qwen3.8 Flash’s fast, cost-effective positioning and check the exact model ID, LLMAPI catalog access, client protocol and billing mode before integration.

2026-11-04 5

LLM API Editorial Team

API Integration

Qwen3.8 Max API Guide: Task Fit, Model ID and Billing Checks

Evaluate Qwen3.8 Max for reasoning and coding, then verify the exact account model ID, client protocol and billing mode before configuring an LLMAPI client.

2026-11-04 4

LLM API Editorial Team

API Integration

DeepSeek V4 Pro API Integration: Model Names, Endpoints and Migration Checks

Configure DeepSeek V4 Pro with OpenAI-compatible requests, distinguish Anthropic base URLs, and check LLMAPI model IDs, protocol support and billing access.

2026-11-03 4

LLM API Editorial Team

API Guides

Gemini 3.8 Flash API Guide: Model ID, Client Setup and Access Checks

Use the exact Gemini 3.8 Flash model ID, choose the right LLMAPI client base URL, and check subscription access separately from API billing and protocol support.

2026-10-28 5

LLM API Editorial Team

API Guides

GPT-6.1 Terra: Model ID, Responses API and Migration Checks

Use the correct GPT-6.1 Terra model ID, start with the Responses API, review vision and tool migration checks, and distinguish official support from LLMAPI access.

2026-10-27 5

LLM API Editorial Team

API Guides

GPT-6.1 Sol: Model ID, Responses API Quick Start, and Migration Checks

Use the official gpt-6.1-sol model ID in a Responses API request, check reasoning and tool compatibility, and verify billing-mode access before switching.

2026-10-23 4

LLM API Editorial Team

Engineering

Sub2API Billing Vulnerability and Fix Verification

Learn how ErrAPIKeyNotFound can roll back Sub2API billing, verify the fix in v0.2.17, and audit missed charges without double billing.

2026-10-22 10

LLM API Editorial Team

Client Setup

Claude Sonnet 5.5: Claude Code Setup and Model ID Guide

Configure Claude Code with claude-sonnet-5-5 and the correct LLMAPI base URL. Separate official model specifications from catalog listings and account access.

2026-10-21 4

LLM API Editorial Team

API Guides

Claude Fable 5.1 Migration Guide: Model ID, Thinking and Client Setup

Choose the exact Fable 5.1 model ID, configure Claude Code for LLMAPI, review always-on thinking, and check your account's model access before migrating.

2026-10-15 4

LLM API Editorial Team

Troubleshooting

Structured Outputs 400 Errors: Fix strict JSON Schema Before Retrying

Check endpoint wrappers, required and nullable fields, nested object definitions and common strict JSON Schema errors locally before retrying an API request.

2026-10-13 5

LLM API Editorial Team

Troubleshooting

Tool Call ID Errors: Match Results Across OpenAI and Claude APIs

Trace mismatched tool results across Chat Completions, Responses and Anthropic Messages with synthetic JSON, offline checks and history-trimming diagnostics.

2026-10-13 5

LLM API Editorial Team

Top-Up Support

ChatGPT Top-Up Session Expired? Continue Your Existing Order

Resume a paid ChatGPT top-up through My Orders, handle requested actions, and learn when to contact support—and why passwords and sessions should not be emailed.

2026-10-08 3

LLM API Editorial Team

API Guides

Claude Haiku 5.5 API Guide: Model ID, Setup and Billing Checks

Connect Claude Haiku 5.5 with the exact model ID, choose the correct client URL, and check subscription versus API billing before your first request.

2026-10-08 4

LLM API Editorial Team

API Guides

GPT-6 and GPT-6.1: Model IDs and Responses API Setup

Choose the documented GPT-6 or GPT-6.1 model ID, make a Responses API text request, and separate OpenAI specifications from LLMAPI subscription access.

2026-09-26 5

LLM API Editorial Team

Troubleshooting

API Returns 200 but No Text? A Streaming Troubleshooting Guide

Diagnose empty API answers by checking response events, completion and client parsing. Includes a small Python regression example and a safe support checklist.

2026-09-20 3

LLM API Editorial Team

Engineering

429 Retry-After: Stopping a Rate-Limit Retry Storm

A Mythos V3 engineering case study on adding correct 429 Retry-After headers, separating quota gates, and reducing five-minute application 429s from 1,050 to 7.

2026-08-21 8

Yazhou Hu

Engineering

Node.js Event Loop Blocking: Fixing an O(n²) Prefix-Hash Hot Path

A Mythos V3 engineering note on diagnosing Node.js event loop blocking, replacing quadratic prefix hashing with one linear pass, and proving byte-for-byte equivalence.

2026-08-21 9

Yazhou Hu

Guide

Claude Opus 5 to Opus 5.5: Model ID, Claude Code Setup, and API Migration

Migrate to claude-opus-5-5 with Claude Code setup, request-breaking changes, progress-text checks, and separate subscription and API billing guidance.

2026-08-14 6

LLM API Editorial Team

Comparison

Claude Opus 5 vs Fable 5: Choosing Opus 5.5 or Fable 5.1

Compare Opus 5.5 and Fable 5.1 by official positioning, thinking behavior and migration risks, then check model access and pricing for your billing mode.

2026-08-11 5

LLM API Editorial Team

Guide

Claude API Pay-As-You-Go: Costs, Billing and Setup

Understand metered Claude API costs, compare billing options, check model access, and connect the right endpoint and key before making your first request.

2026-06-30 6

LLM API Editorial Team