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Short answer

Official relay means resources forwarded through a vendor’s official API or official cloud marketplace. Reverse-engineered (reverse) means access obtained through unofficial interfaces. When both routes call the same model, single-turn answers can be very close. The real differences are stability, protocol compatibility, feature completeness, cache efficiency, concurrency, and long-term sustainability.
  • APIYI is official-relay by default. Reverse groups are a supplement for personal learning, cost-sensitive workloads, and non-critical tasks.
  • Production workloads, coding Agents, and enterprise customers: prefer official relay.
  • Personal learning, simple chat/translation/summarization, and cost-sensitive workloads: reverse groups are usable.
  • APIYI currently has exactly three text/coding reverse groups: Claude_Reverse, Codex_Reverse, and Gemini_Reverse. Other vendors’ text models use the official-relay Default / SVIP groups by default.
  • Image -all / -vip models are a separate reverse line, mostly served by Default; some models that need URL output use image2_OSS. Check the console for the exact mapping. They are not part of those three groups.
  • APIYI labels the source in group names and documentation. Reverse groups are never presented as official direct connections.
These are typical patterns, not a claim that every official-relay channel beats every reverse channel. Official relay also runs into vendor capacity limits, and a high-quality reverse resource pool can be temporarily better on speed, concurrency, or stability for some workloads. Judge the specific channel, time window, and your own tests.
This article is about APIYI groups in general, not one specific model. For model-level differences, check the model documentation and run your own tests.

Official-relay and reverse groups on APIYI

Separate the group from the model: the group is the channel on the token, and the model is the model field in the request. APIYI uses groups to organize sources and use cases, but a general group can contain both official-relay and reverse image models. APIYI is official-relay by default. Groups that are mostly official relay include Default, SVIP, ClaudeCode, Claude_Enterprise, CodexResponses, image2Enterprise, and NB-Enterprise, plus the video groups SeeDance2 and Wan&HappyHorse. See Groups for the full list, discounts, and model coverage.

Reverse groups (supplement)

Reverse groups are a supplement and do not promise the same SLA, concurrency, or feature completeness as official relay.
Default / SVIP are mostly official relay, but they also contain reverse image models such as gpt-image-2-all, gpt-image-2.6-all, and the -vip series. Check both the group and the model, not just the group name.

Core differences: it is not only model intelligence

Stability and performance

Protocol and features

Versions, compliance, and sustainability

Reverse resources are outside the vendor’s official commercial API terms. This article is a technical explanation, not legal advice. Assess compliance for your own enterprise procurement and production use.

Why Agents should still prefer official relay when single-turn quality is close

A coding Agent’s success rate is not determined by single-turn answers. One malformed tool-call argument, one missing JSON field, or one interrupted stream can fail and restart an entire task. Single-turn quality can look identical while multi-turn success rates diverge. Three problems are amplified in Agent workloads:
  • Tool-call structure: Reverse chains may rewrite or ignore parameters, increasing the chance of wrong function names, argument order, or nesting.
  • Cache prefixes: System prompts, tool definitions, and history form a long prefix across turns. If the reverse chain cannot pass cache_control through, cache hits drop and both cost and latency rise.
  • Error codes and retries: Inaccurate error mapping can make retry logic treat a recoverable error as fatal, or the other way around.
For Claude Code, Codex, Gemini CLI, and OpenClaw workflows, prefer official relay by default. Use reverse groups only as a cost supplement or for non-critical tasks.

When to prefer official relay, and when reverse is acceptable

Caching is more than a hit rate

Official Claude caching has explicit prefix matching, cache_control markers, and 5-minute / 1-hour TTLs. The cache_creation_input_tokens and cache_read_input_tokens fields show writes and reads directly. OpenAI uses automatic prefix caching; Gemini uses implicit caching with a moderate hit rate. If a reverse chain only forwards requests and cannot fully pass cache-control parameters, hit rates drop. Long conversations, fixed system prompts, and large tool definitions amplify the cost difference. When choosing a channel, do not only ask whether caching exists; measure the actual cache-read share for the same prefix. See Does APIYI support cache billing? for cache mechanics and billing, and Claude prompt caching for Claude parameters.

How to evaluate a channel: five metrics

If you need to choose between official relay and reverse, run a fixed test set and record these five numbers: Cache fields differ by vendor: Claude exposes cache_read_input_tokens, while OpenAI uses fields such as prompt_tokens_details.cached_tokens. Read the field from the actual response.
Single-turn benchmarks only show whether the model can answer. These five metrics show whether the channel can run a business.

APIYI channel principles

  • Official relay by default: APIYI uses vendor official APIs and official cloud marketplaces by default. Reverse is a cost supplement, not the default channel.
  • Label the source: Claude_Reverse, Codex_Reverse, and Gemini_Reverse are marked as reverse in group names and documentation. They are never described as official direct connections.
  • Production prefers official relay: Default, SVIP, Claude_Enterprise, CodexResponses, image2Enterprise, and NB-Enterprise carry production traffic. For image models, choose by the specific model’s source.
  • Official relay for complex Agents: Tool calls, multi-turn tasks, and long context demand protocol consistency.
  • Reverse for learning and cost optimization: Reverse groups do not promise the same SLA, concurrency, or feature completeness as official relay.
  • Enterprise customers: Use Claude_Enterprise, image2Enterprise, or NB-Enterprise when guarantees matter. Contact support for SLA and procurement options.
  • Channels change: Upstream resources, model versions, and group multipliers can change. Trust the console and Live Updates.
If you only look at single-turn answers, official relay and a good reverse channel can look very close. What official relay is really worth is behavioral consistency, predictable stability, complete features, and long-term sustainability. For production businesses, those four determine support cost and customer retention, not just unit price.

Groups

All groups, multipliers, discounts, and selection guidance by vendor and model

Tokens & Groups

Create tokens and configure primary and fallback groups

What Is a Group?

User groups vs token groups

Cache Billing

Cache behavior and billing for Claude, OpenAI, and Gemini

GPT Image: Official vs Reverse

Parameter, price, and quality differences for image models

Model Pricing

Prices and specifications for every model