AIFast GPT, Claude and Gemini API Developer Center
Focused GPT, Claude and Gemini model access
Link offers GPT, Claude and Gemini models. Follow reproducible steps from your first request to production troubleshooting, and check live model IDs, endpoints, groups and prices. Monthly plans apply to specified groups; do not assume a GPT or Claude plan covers Gemini.
# Query currently available models
curl https://www.aifast.link/v1/models \
-H "Authorization: Bearer $AIFAST_API_KEY"OpenAI CompatibleClick the complete question to enter the topic center
From judgment methods, configuration steps to troubleshooting and acceptance, avoid repeated searches between scattered tutorials.
First check the protocol structure, request model and response model, Token field, random dynamic questions, SSE and tool calls, and then repeat sampling at different time periods. Neither a single answer, a model readme, nor a model field can independently prove the identity of the underlying model.
Enter the theme center 02 · OPENAI COMPATIBLEWhat Is an OpenAI-Compatible API? Scope and LimitsModels, availability and prices on Link are live information. Copy a GPT, Claude or Gemini model ID from the current account catalog and make a minimal request through the OpenAI-compatible Base URL. A successful chat does not prove SSE, tool calls or native Claude Code protocol support.
Enter the theme center 03 · DEVELOPER TOOLSAI development tool custom API access centerCursor, Codex, Claude Code, and Dify, even if they all support custom APIs, may use Chat Completions, Responses, Anthropic Messages, or plugin protocols respectively. First confirm the protocol entry of the current version of the client, and then configure the Base URL, environment variables and real model ID.
Enter the theme centerStart with your current task
There is no need to read from the beginning, just choose the step that needs to be solved most now.
Create an API Key, query the model list, and send the first request.
View quick start 02Codex, Claude Code and CursorConfigure and accept respectively according to Responses, Anthropic Messages and OpenAI Compatible protocols.
Enter the Development Tools Center 03Positioning call errorCheck 401, 429, 502, model name and address errors one by one.
Enter the troubleshooting manualPress the model platform to start accessing
Select the target model platform, first query the current model ID, and then complete the minimum request and production acceptance.
Check Gemini model IDs and groups, and distinguish the OpenAI-compatible address from the generateContent path.
Check the configuration differences between Claude model ID, protocol boundary, streaming output and Claude Code.
Migrate Python and Node.js SDK, handle Base URL, Key conflicts and /v1/v1.
Confirm three fields before accessing
Most first-time access problems can be located from the address, authentication, and model identification.
OpenAI Compatible address is usually filled in https://www.aifast.link/v1, and check if the client will append again /v1.
Use Authorization: Bearer Authentication, and save the key in the server environment variable or key system.
from the console or /v1/models Copy the actual model ID; do not replace it with a Chinese title, manufacturer name, or model series name.
Concerned about capability degradation, model impersonation, or route substitution?
First check the protocol, model declaration, token, dynamic questions, SSE and tool calls before deciding whether to connect. The report provides itemized evidence and does not package black box screening as manufacturer certification.
Open the free detection toolLLM intelligence detection and model quality testing: downgrading from model declaration, token, dynamic questions, SSE, tool calling and business baseline troubleshooting capabilities, and distinguishing routing changes from occasional fluctuations.
Use protocol metadata, model declarations, dynamic capability probes, and repeated comparisons to identify impersonation or substitution risks without treating a single anomaly as proof of fraud.
Explain what the model field can prove, why a gateway can rewrite it, and how to cross-check it with token usage, capability probes, and repeated tests.
Explain compatibility scores and pass, inconclusive, fail, and observation signals, then provide a fair comparison and retesting method for compatible GPT, Claude, and Gemini APIs.
Compare Python and Node options, timeout units, paths and Chat versus Responses bodies when curl works but the SDK fails, with an offline official-SDK example.
Use tools first to get verifiable results
No need to download and install. Check the existing API, correct the base URL, or estimate the token cost based on real usage.
Check model declarations, tokens, dynamic questions, SSE and tool calls.
Start testing Configuration troubleshootingBase URL checkerLocate duplicate /v1, full endpoint and client path splicing issues.
check address cost estimateToken cost calculatorCalculate costs for input, output, batch jobs, and failed retries.
Estimate cost development toolsClaude Code setupVerify Anthropic Messages, streaming output, tool calls, and model mappings.
View setup guide development toolsCursor custom APICheck the Base URL, model ID, API key, and client support boundaries.
View configuration guide Workflow setupConfigure GPT, Claude and Gemini in DifyConfigure the model provider, a minimal chat, and workflow nodes, then verify the interface layer by layer.
View configuration guideGemini API setup: model IDs, Base URL and protocols
Set up Gemini APIs on AIFast Link with an offline model-ID checker and request template. Verify Base URL, protocols, group access and billing before calling.
Quick StartClaude API access in China: OpenAI-compatible setup and checks
Query a live Claude model ID, run a minimal call, verify streaming, and troubleshoot 401, 404, 429, and protocol compatibility.
Quick StartOpenAI API Access from China: Base URL, SDK, 401, and 429
Configure the OpenAI SDK Base URL, query live model IDs, and troubleshoot /v1/v1, 401, 429, and API compatibility issues.
TroubleshootingOpenAI Compatible Base URL Online Checker
Check OpenAI-compatible API URLs, repeated /v1, complete endpoints, HTTPS, and final request paths to locate /v1/v1 and 404 errors.
Models and CostLLM API Token Cost Calculator
Estimate token and billed-retry costs, then compare pay-as-you-go with monthly plans using active days, daily limits and overages. No API key needed.
Quick StartOpenAI-Compatible API tutorial: integration and request verification
Configure the Base URL with curl, Python and Node.js, verify the model list and first request, and troubleshoot 401, model not found and /v1/v1 errors.
Quick StartAIFast 3-minute quick start
Register, create an API key, query live model IDs, and send your first request in the fewest steps.
Quick StartLLM API streaming and SSE integration guide
Compare SSE terminal events, truncated output and missing usage across three protocols, with curl, Python and Node.js checks.
Quick StartLLM API Pre-production Checklist
Verify keys, protocols, timeout and retry behavior, logging, cost monitoring, staged rollout, and rollback readiness.
Quick StartWhat is LLM API gateway? Access methods and risk checks
Explain the differences between API gateway, OpenAI Compatible, and unified gateway, and give the protocol, security, and cost checks that must be verified before access.
Quick StartHow to choose an OpenAI-compatible API service: a 12-point checklist for teams in China
Compare cloud platforms, global aggregators, self-hosted gateways, and unified services for networks in China using 12 OpenAI-compatible API criteria: protocol support, models, reliability, token accounting, rate limits, security, billing, and migration cost.
Platform ReferenceAIFast Link platform facts, official entry points and verification limits
Review AIFast Link domains, Base URL, GPT, Claude and Gemini scope, and group-specific plan rules to check access and billing conditions.
Platform ReferenceEnterprise LLM API Unified Procurement, Billing and Invoicing Checklist
Plan model coverage, concurrency, project isolation, billing checks, invoicing, incident handling, migration, and acceptance requirements.
Platform ReferenceIs an LLM API degrading model capability? A reproducible test checklist
LLM intelligence detection and model quality testing: downgrading from model declaration, token, dynamic questions, SSE, tool calling and business baseline troubleshooting capabilities, and distinguishing routing changes from occasional fluctuations.
Platform ReferenceHow to investigate model impersonation and route substitution in an LLM API
Use protocol metadata, model declarations, dynamic capability probes, and repeated comparisons to identify impersonation or substitution risks without treating a single anomaly as proof of fraud.
Platform ReferenceCan a matching API model field prove the underlying model is authentic?
Explain what the model field can prove, why a gateway can rewrite it, and how to cross-check it with token usage, capability probes, and repeated tests.
Platform ReferenceHow to read an LLM API gateway check report
Explain compatibility scores and pass, inconclusive, fail, and observation signals, then provide a fair comparison and retesting method for compatible GPT, Claude, and Gemini APIs.
Platform ReferenceAIFast Link GPT, Claude and Gemini API Test Template: Capability and Cost Review
Compare current AIFast Link GPT, Claude and Gemini models using the same tasks. Record model access, protocols, latency, tokens and billing plans, then choose based on completed tasks.
Platform ReferenceOpenAI SDK Troubleshooting and Protocol Matrix
Compare Python and Node options, timeout units, paths and Chat versus Responses bodies when curl works but the SDK fails, with an offline official-SDK example.
Tool IntegrationCursor Custom API Setup and Troubleshooting
Configure a custom API key, Base URL, and exact model ID; inspect the request path; and troubleshoot API Key Valid, 401, and model not found errors.
Tool IntegrationCursor2API Setup: Fix 401, Truncation, and Migrate APIs
Distinguish Cursor2API from official custom APIs, troubleshoot 401, output truncation, tool-call, and model-change issues, then migrate to a standard API with a repeatable checklist.
Tool IntegrationClaude Code API setup: custom Base URL and Anthropic Messages
Configure ANTHROPIC_BASE_URL, authentication variables, and model mapping to distinguish Anthropic Messages from the OpenAI Compatible protocol.
TroubleshootingClaude Code API Troubleshooting: Protocol Checks Before AIFast Link
Before using Claude Code with AIFast Link, verify that its required protocol is available. Check the Base URL, authentication, streaming, tool calls and common 401, 403, 429 and 502 errors; a model name does not prove compatibility.
Tool IntegrationCodex Custom Provider Setup in config.toml
Configure a Codex custom provider for the Responses API, set environment variables and model IDs, then verify tool calls with a minimal file-editing task.
TroubleshootingCodex gateway API acceptance and troubleshooting
Use a 20-minute checklist to verify configuration priority, API keys, Responses paths, streaming, tool calls, context compaction, and 401, 404, 429, and 5xx errors.
Tool IntegrationOpenClaw API configuration, model verification and common errors
Add a standalone custom provider, configure the API adapter, Base URL and real model ID, and verify streaming output and tool calls.
Tool IntegrationHermes Agent API setup: custom endpoint and Base URL
Configure Base URL, API Key and real model ID using hermes model and custom endpoint.
Tool IntegrationConfigure the AIFast API in Dify
Configure the Base URL, API Key, model type and real model ID, and verify the workflow and knowledge base nodes.
Tool IntegrationConfigure AIFast in OpenWebUI
Add an OpenAI Compatible connection, load a list of models, and troubleshoot address, container network, and streaming output issues.
Tool IntegrationChatbox and Cherry Studio integration guide
Add an OpenAI-compatible provider and configure its API endpoint, API key, and live model ID.
Troubleshooting401, 429, 502 API error troubleshooting
Use HTTP status codes to identify API key, quota, rate-limit, gateway, and upstream model problems.
Troubleshooting401 invalid_api_key and API Key invalid troubleshooting
Troubleshoot 401 errors by checking request headers, environment variables, the Base URL, the key provider, and configuration overrides. Avoid ineffective retries and key exposure.
TroubleshootingFix OpenAI API 429: Rate Limits, Quota, and Retries
Separate request-rate, token-rate, concurrency, quota, and duplicate-retry causes, then recover with Retry-After, exponential backoff, and request queues.
Troubleshooting502 Bad Gateway, stream disconnected and SSE disconnection troubleshooting
Use the last event to distinguish 502 errors, SSE interruptions, output limits and tool turns, then check timeouts, retries and actual usage.
TroubleshootingFix API model not found: model ID, Base URL and 404 troubleshooting
Does the GPT API report model not found or 404? Distinguish ChatGPT from API errors, then check the model ID, permissions, Base URL, /v1/v1 and endpoint against the response. Includes a key-free URL checker and redacted support checklist.
TroubleshootingAPI Key Security Usage Checklist
Keep API keys out of repositories, frontend code, screenshots, and logs to reduce leakage risk.
Models and CostHow to choose between GPT, Claude and Gemini models
Select models based on input and output types, latency, cost, and task verifiability.
Models and CostLLM API Cost Guide: Choosing Top-Ups or a Monthly Subscription
Estimate AIFast Link GPT, Claude and Gemini API costs by tracking top-ups, monthly subscriptions, live prices, quotas and actual tokens separately. Do not mix billing data or outdated prices from other sites.
Choose the fastest path to your first successful API call
Start with a live gateway check, copy the OpenAI-compatible base URL, or compare Link pay-as-you-go billing and monthly plans before moving a project into production.