korouter.ai

What is KoRouter?

KoRouter is an LLM gateway: a single OpenAI-compatible API and one key that route requests to a catalogue of leading models from multiple providers. Instead of signing up with each provider and managing separate keys, you change one base_url in your client and KoRouter handles provider switching, automatic failover and pay-as-you-go billing. It also exposes an Anthropic-compatible endpoint, so tools built for either protocol can point at the same service.

What you actually get

• One key, many models. Bare model IDs (for example claude-fable-5) in a live catalogue spanning Anthropic, OpenAI, DeepSeek, GLM, Kimi and others.
• Two protocols. OpenAI-style clients use OPENAI_BASE_URL plus OPENAI_API_KEY; Claude Code-style clients use ANTHROPIC_BASE_URL plus ANTHROPIC_AUTH_TOKEN.
• Failover and routing. If a provider is unavailable, KoRouter switches automatically rather than failing the request.
• Pay-as-you-go. No monthly fee and no stated minimum spend; one credit balance covers all models, with token, image and request prices drawn from a live billing catalogue.

Where it fits

The clearest audience is developers running AI coding assistants — the page names Claude Code, Codex, Cline, OpenCode, Aider and similar clients. If you already have one of those configured, the migration is genuinely a one-line change: swap the base URL, paste a key from the console, and the existing tool keeps working while gaining access to every model in the catalogue. A second audience is teams that want a single billing line and one integration point instead of N provider accounts.

The trade-off is the usual one for a gateway: you add a middle layer between your application and the model provider. That buys convenience, failover and (per the site) lower prices, but it also means your traffic and billing pass through a third party, and model availability depends on KoRouter's upstream relationships rather than your own contracts. For latency-sensitive or compliance-bound workloads, weigh that carefully.

On price

KoRouter advertises savings of up to 63% against official API prices, with per-model figures such as claude-opus-5-5 at 35% off and gpt-6.1-sol at 63% off, shown as input/output rates per million tokens. Treat these as the vendor's own claims and verify current numbers on the live pricing page before committing, since gateway pricing and model catalogues change frequently.

Next step

Pick one tool you already use, note its current base URL and key, then point it at KoRouter with a small credit balance and run a few real prompts. Compare output quality, latency and cost against your existing setup for a week before migrating anything production-critical. For a broader view of the model providers themselves, see OpenAI and Anthropic.

How do I switch my existing OpenAI or Anthropic client to KoRouter?

Switching is a two-line change: point your client's base URL at KoRouter and replace the API key. KoRouter exposes both OpenAI- and Anthropic-compatible endpoints, so the same key works across either protocol.

For OpenAI-compatible clients

This covers Codex, Cline, Aider, OpenCode and anything else that reads OPENAI_BASE_URL:

export OPENAI_BASE_URL="https://korouter.ai"
export OPENAI_API_KEY="sk-********"

For Anthropic-compatible clients

Claude Code and other Anthropic-protocol tools use different variable names:

export ANTHROPIC_BASE_URL="https://korouter.ai"
export ANTHROPIC_AUTH_TOKEN="sk-********"

Model names are passed as bare IDs (for example claude-fable-5), so any model-specific setting in your config stays as-is. If your client stores the endpoint in a config file rather than an environment variable, edit that field instead — the value is the same.

What to check before you commit

• Protocol match. Confirm whether your tool speaks the OpenAI or Anthropic schema. Sending an Anthropic-shaped request to an OpenAI endpoint is the most common cause of a confusing 400 error after a switch.
• Key location. Tools often read the key from a shell profile, a project .env, or a GUI settings pane. If the old key is still set somewhere with higher precedence, the switch appears not to work.
• Model IDs. A client that hardcodes gpt-4o or similar won't automatically use the cheaper catalog entries; you choose the model ID explicitly.

A practical test

Run one small request through the new endpoint before changing anything else — a single short completion from the CLI or a one-line script. If it returns, your routing is correct and you can migrate the rest of your configuration with confidence. If it fails, revert the base URL and check the key and protocol first.

When this is worth doing

The trade-off is straightforward: you accept a third-party gateway in the request path in exchange for one key across providers, automatic failover, and per-token rates below official list. That suits individual developers and small teams running several coding assistants who don't want to manage separate provider accounts and billing. Teams with strict data-residency or procurement requirements may prefer direct provider contracts, where the endpoint and terms are under their own control.

How much cheaper is KoRouter compared to official API prices?

KoRouter advertises savings of up to 63% versus official API prices, with the discount varying by model rather than applying uniformly across the catalog. The page's own examples put two models side by side:

The headline "up to 63% off" therefore describes the best case, not a flat rate. A featured list on the page also shows claude-fable-5.1 at 35% off, deepseek-v4.1-flash at 56% off, and gpt-6.1-sol at 63% off — so a mixed workload will land somewhere between roughly a third and two-thirds below official list prices.

What the discount does and doesn't cover

The percentages are quoted on token prices (input, output, and cache read in the claude-opus-5-5 example). KoRouter states there is no monthly fee and no minimum spend, with one prepaid credit balance covering every model, and that token, image, and request prices come from a live billing catalog. If your workload includes image generation or per-request charges, check those line items individually rather than assuming the token discount carries over.

A realistic cost check

Suppose you spend $500 a month on official APIs, weighted toward a heavily discounted model. At 63% off you'd pay about $185; at 35% off, about $325. The gap between those two outcomes is large enough that the useful question isn't "how much cheaper is KoRouter" but "how much cheaper is my model mix."

Next step: list the models you actually call and their monthly token volumes, then pull the current per-model input/output rates from the KoRouter pricing page and compare them against each provider's official pricing page for the same models. That gives you a blended discount figure for your workload instead of the marketing ceiling. If your traffic is concentrated in one or two models, the answer is essentially the discount on those models; if it's spread across many, expect a figure closer to the middle of the range.

How does KoRouter's automatic routing and failover work?

KoRouter presents itself as an OpenAI- and Anthropic-compatible gateway: you point your existing tool at its base URL, and it handles provider selection behind that single endpoint. Its page describes automatic routing and automatic failover as built-in behaviours of that layer, so from the client side you keep one key and one base URL while KoRouter decides which upstream provider serves each request and moves to another when one is unavailable.

What this means in practice

• Routing: your request is matched to a model in the live catalog and dispatched to a provider that can serve it. You don't manage per-provider keys or endpoints yourself.
• Failover: if a provider fails or is unreachable, the gateway is designed to retry against another provider rather than returning the error to your app.
• Client compatibility: because it exposes both OpenAI- and Anthropic-style endpoints, tools such as Claude Code, Codex, Cline, Aider and OpenCode can be redirected by changing a base_url and key.

Trade-offs worth weighing

A concrete scenario

A team runs an AI coding assistant in CI. Instead of storing several provider keys and writing retry logic, they set one environment variable pair for the gateway. When a provider has an outage mid-run, the gateway is meant to absorb it and the job completes. The cost is an added hop and less direct control over which provider answers — acceptable for coding assistance, less so where you must pin a specific model version for reproducibility.

Next step

Test failover deliberately rather than assuming it: send a batch of requests and inspect the responses and any per-request metadata for which provider served them. If the gateway's logs don't show provider attribution, treat routing as opaque and evaluate whether that fits your auditing needs. For comparison, OpenAI's own platform documents its own retry and rate-limit behaviour at OpenAI, and Anthropic's API guidance is at Anthropic.

Which models can I access through KoRouter's single API?

KoRouter's catalog is organized around a single OpenAI-compatible endpoint, with an Anthropic-compatible endpoint for tools that expect it. The models named on its page span several families:

• Anthropic-style models: claude-opus-5-5, claude-fable-5.1, claude-fable-5, claude-sonnet-5, claude-sonnet-5-5, claude-haiku-4-5, claude-opus-4-6, claude-opus-4-7, claude-opus-4-8, claude-opus-5
• OpenAI-style models: gpt-6.1-sol, gpt-6-sol, gpt-5.6-sol, gpt-5.6-terra, gpt-6-astra
• Other providers: deepseek-v4.1-flash, glm-5.3, glm-5.3-flash, kimi-k3

Model IDs are used as bare strings (for example, claude-fable-5), so switching models is usually a matter of changing that string rather than rewriting integration code.

What this means in practice

If you maintain several AI coding tools — say Claude Code for one workflow and Cline or Aider for another — the practical benefit is that each tool points at the same base URL and key while you pick models per task. A cheap, fast model such as deepseek-v4.1-flash or glm-5.3-flash can handle routine edits, while a stronger model like claude-opus-5-5 or gpt-6.1-sol takes harder reasoning work. Because KoRouter also advertises automatic routing and failover, a request can fall back to another provider if one is unavailable, which matters more when you depend on a single key across many tools.

Two caveats worth checking before you commit:

1. Catalog freshness. The listed model names include versions that may not match what providers currently serve. Treat the live catalog as the source of truth and confirm the exact IDs in your console before wiring them into scripts.
2. Compatibility limits. OpenAI- and Anthropic-compatible endpoints cover the common chat and completion patterns, but provider-specific features (certain tool-calling formats, caching controls, or beta parameters) may behave differently through a gateway. Test the specific features your app relies on.

Next step

Start with one low-risk tool: set its base URL and key to KoRouter, run a small task with a mid-tier model, then compare output quality and latency against your current direct setup. If that holds up, expand to your other clients and only then consider moving production traffic.

Do I need a monthly subscription or minimum spend to use KoRouter?

No. KoRouter is described as pay-as-you-go: no monthly fee and no minimum spend, with a single credit balance that covers every model in the catalog. You top up, and usage is drawn down per token, image, or request based on the live billing catalog.

What that means in practice

• You pay for what you actually use. A light month — a few code reviews, occasional refactors — costs little. A heavy month costs more, but you aren't locked into a tier.
• One balance, many models. You don't need separate accounts or prepaid credits per provider; the same balance covers whichever model you route to.
• No idle cost. If you stop using it, you stop paying. That is the main trade-off versus a flat subscription: predictable bills are harder to forecast, and you need to keep an eye on spend if you run long agent loops.

A concrete scenario

Say you wire KoRouter into a coding client by changing one base_url and an API key, as the setup notes describe for OpenAI- and Anthropic-compatible tools. You use it for a week of intermittent work, then leave it untouched for a month. Under a subscription model that idle month still bills you; here it doesn't. Conversely, if you run a large automated pipeline every day, a subscription with a fixed cap could be cheaper — so estimate your monthly token volume before deciding.

Next step

Check the pricing page for current per-model rates and confirm the minimum top-up amount in your console, since that is the practical floor on your first payment rather than a recurring commitment. If you want to compare the underlying model costs, the official rate cards from OpenAI and Anthropic give you the baseline the discounts are measured against.