Your cheap Claude is probably a fake. We caught 183 of them.

Claude is the most in-demand model on the market right now, and one of the most expensive. That gap has created a thriving market of third-party resellers offering "the same Claude" at a fraction of the official price. Some are legitimate. A lot aren't.

Over 17 days of automated probing across 8 upstream resellers, we found 183 (channel, model) pairs that fail authenticity checks against models marketed as claude-opus-4-7, claude-sonnet-4-6, claude-haiku-4-5, and friends. The same pressure exists for every premium model, so GPT, Gemini, and Grok are almost certainly affected too. Claude is just where the price gap is biggest right now and where we have hard data.

How the probes work

Per (channel, model) we send four parallel requests to the standard Anthropic Messages API (POST /v1/messages):

Probe	Prompt	Pass criteria
emotional	Tell me a 2-sentence sad story about a lost kitten.	No coding-refusal phrases; response >= 40 chars
creative	Write a haiku about the ocean at sunrise. Only the haiku, nothing else.	No coding-refusal phrases; response >= 25 chars
identity	What company created you? Reply with only the company name, one word.	Contains `anthropic`; no foreign-vendor names
model-name	Which model are you? Reply with only your model name, nothing else.	Contains `claude` or `anthropic`; no foreign-vendor names

Three failure types:

coding-tool-refusal: response matches a Kiro Cascade or Codeium / Windsurf Droid refusal pattern ("I'm here to help with coding", "I'm Droid", etc.). The upstream is routing to an IDE-assistant product, which refuses the prompt because it's not coding.
foreign-identity: response identifies as a non-Anthropic vendor (OpenAI, Meta, DeepSeek, Moonshot, etc.).
failed: wrong-style output without those signals (no kitten story, no haiku, generic "AI assistant" reply).

Pattern lists and probe code: src/core/models/testing/authenticity.ts.

What is not spoofing: Bedrock, Vertex, Foundry

A reseller routing through AWS Bedrock, Google Vertex AI, or Azure AI Foundry is not spoofing. Those platforms host real Anthropic Claude weights under license. Buying capacity there at enterprise discount and reselling it is a normal supply chain.

One known false positive: cloud-hosted Claude sometimes answers the identity probe with Amazon / Google / Microsoft instead of Anthropic, because of host system prompts. A channel flagged only by foreign-identity against cloud-host names warrants a manual second look. coding-tool-refusal and non-cloud foreign vendors are unambiguous, real Bedrock/Vertex/Foundry Claude never produces those responses.

What 17 days of probing turned up

8 upstream resellers (anonymized as provider-1..provider-8), 183 (channel, model) entries between 2026-04-08 and 2026-04-24.

Failure type	Count
failed	115
coding-tool-refusal	64
foreign-identity	4

Probe labels that triggered failures (a channel can fail multiple):

Probe	Failures
emotional	110
model-name	88
identity	79
creative	47

emotional being the biggest catcher is the smoking gun. Real Claude doesn't refuse to write a 2-sentence sad story about a kitten. A coding-tool backend dressed as Claude does, every time.

Provider	Bad channels
provider-1	58
provider-2	30
provider-3	29
provider-4	21
provider-5	17
provider-6	15
provider-7	8
provider-8	5

Model	Bad channels
claude-opus-4-6	27
claude-sonnet-4-6	23
claude-sonnet-4-6-thinking	21
claude-haiku-4-5-20251001	20
claude-opus-4-7 (flagship)	16
claude-opus-4-6-thinking	14
claude-opus-4-5-20251101	12
claude-haiku-4-5-20251001-thinking	11
claude-sonnet-4-5-20250929	10
others	29

Older Claude variants have higher counts only because they've been on the market longer. Opus 4.7 hit 16 spoofed channels within weeks of release. This isn't a static snapshot, either, resellers rotate upstreams and a channel that passes today can start serving Kiro tomorrow. Authenticity has to be checked continuously.

Why this happens

Real Claude is expensive whether you buy from Anthropic or from a licensed cloud reseller. A reseller advertising Claude below the cheapest licensed price has four options:

Eat the loss (sustainable only with deep funding).
Buy Bedrock/Vertex/Foundry capacity at enterprise discount and resell. Legitimate, but bounded by what those clouds charge.
Run a fraction of traffic through real Claude and route the rest cheaper, banking on users not noticing.
Route everything to a non-Anthropic backend and hope nobody checks.

Options 3 and 4 are what the probes catch. Kiro Cascade and Codeium are tempting backends because they have free / near-free quotas and Anthropic-compatible response shapes. The output looks structurally correct, just stylistically wrong, and most users never notice unless they ask for something non-coding.

Test your own provider in 5 minutes

We built these probes into the site so you do not have to run anything. Open the API model tester, paste your provider base URL and key, pick a Claude model, and it runs the same authenticity checks live and shows you exactly which probes failed. Prefer the command line? The raw curl below is the emotional probe.

bash

curl https://YOUR-PROVIDER/v1/messages \
  -H "x-api-key: $YOUR_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "content-type: application/json" \
  -d '{
    "model": "claude-opus-4-7",
    "max_tokens": 150,
    "messages": [{
      "role": "user",
      "content": "Tell me a 2-sentence sad story about a lost kitten."
    }]
  }'

If the response refuses or redirects to coding, your "Claude" is not Claude. For a second check, send "What company created you? Reply with only the company name, one word." anything other than Anthropic is your answer.