Head to head · LLM inference · October 2026 research run

Claude Mythos 5.2 vs Tencent Hy4

Claude Mythos 5.2 scores 77.3 (BB) on agent readiness against Tencent Hy4's 64 (B), and leads in 6 of 7 scored categories. Tencent Hy4 leads on payments & pricing. Both do llm inference.

Best model APIs and inference for AI agents · All 1044 models comparisons

Which one, for what

Claude Mythos 5.2 BB

Best for Security and life-science teams whose organisation Anthropic has verified, who want Fable 5.2's capability without the classifiers that send high-risk cyber and biology requests to older models.

Ahead on

  • Reliability, 60 against 46
  • Schema & documentation, 90 against 73
  • Agent ergonomics, 95 against 86
  • Security & auth, 92 against 71
  • Maintenance & community, 91 against 73
  • Transparency & trust, 85 against 52

Also in its favour

  • Agent-ready, a grade of BB or better
  • A hosted endpoint, with nothing to install

Watch for

Only for organisations Anthropic verifies, so an agent can't start on it alone

Tencent Hy4 B

Best for Long-context agent work, coding and office or finance tasks on a 1M-token context with images, for teams already on Tencent Cloud or happy to verify an account there.

Ahead on

  • Payments & pricing, 45 against 30

Watch for

Weights, licence and system card are promised but not published; tencent/Hy4 didn't answer on Hugging Face on 11 November

Why the edge

Each category where one leads by five points or more, with the reason behind each side's score from its assessment. The numbers are in the table below; this is what they stand for.

Transparency & trust Claude Mythos 5.2 +33

Claude Mythos 5.2 85

Model reading for claude-mythos-5-2 on the Claude API. Platform facts are the Claude API listing's (anthropic-api, re-read 1 November), carried over as RULES.md allows for a model on an already graded platform. Commercial Terms with named contracting parties and Apache 2.0 SDKs (15). Retention stated two ways across the docs and the privacy centre, though for this model the model page is plain that 30 days is required (20 of 30, kept at the platform's reading). Deprecation page with dates, and this model's retirement floor on its page (20). Processing countries and subprocessors named (20). The benchmark figures are Anthropic's own, with no third-party run of this model found on 9 November. 15 + 20 + 20 + 20 = 75.

Tencent Hy4 52

Model reading for hy4 on Tencent Cloud TokenHub. Platform facts are the tencent-tokenhub listing's (checked 1 November), carried over as RULES.md allows for a model on an already graded platform. Closed service under the TokenHub terms, but Tencent's release headline calls Hy4 open source while the weights and system card are only promised 'in the coming days', with no licence stated, and tencent/Hy4 didn't answer on Hugging Face on 11 November (14 of 30). Terms and FAQ agree inputs aren't used for training; the privacy policy renders only with JavaScript and wasn't read (15 of 30). Dated retirement notices and shutdown fields (13 of 20). Processing generally in mainland China for the China site, Singapore for the international one (13 of 20). Every benchmark in the release is Tencent's own or a partner's. 14 + 15 + 13 + 13 = 55.

Security & auth Claude Mythos 5.2 +21

Claude Mythos 5.2 92

Model reading for claude-mythos-5-2 on the Claude API. Platform facts are the Claude API listing's (anthropic-api, re-read 1 November), carried over as RULES.md allows for a model on an already graded platform. Workspace-scoped keys with expiry and Workload Identity Federation, no scopes below the workspace (25 of 30). No training on API data without express permission (20). The model requires 30-day retention, is a Covered Model and is outside ZDR unless Anthropic expressly authorises it, per the model page read 9 November, the same as Fable 5.1 (12 of 15). Usage and cost analytics, Compliance API and OpenTelemetry export (15). security.txt, HackerOne and SOC 2, ISO 27001 and ISO 42001 (20). Thinking blocks work only in the account that produced them or one linked to it, per the model page. 25 + 20 + 12 + 15 + 20 = 92.

Tencent Hy4 71

Model reading for hy4 on Tencent Cloud TokenHub. Platform facts are the tencent-tokenhub listing's (checked 1 November), carried over as RULES.md allows for a model on an already graded platform. Bearer keys limited by model, service, IP range and token quota, long-lived with no rotation (26 of 30). The terms say inputs aren't used to train Tencent Cloud's own models, and Hy4 is first party, so no third party's terms apply (14 of 20). Retention only as long as the service needs, no periods (7 of 15). Per-call audit logs and optional full logs to the customer's CLS (14 of 15). No security.txt; Tencent's TSRC bounty covers Tencent Cloud; no certification checked (10 of 20). 26 + 14 + 7 + 14 + 10 = 71.

Maintenance & community Claude Mythos 5.2 +18

Claude Mythos 5.2 91

Model reading for claude-mythos-5-2 on the Claude API. Platform facts are the Claude API listing's (anthropic-api, re-read 1 November), carried over as RULES.md allows for a model on an already graded platform. Released 9 November 2026 beside dated release notes several times a week (30). 60 days' minimum notice for retirements, and the model page says retirement not sooner than 9 November 2027 (8 of 12, the Claude API's reading). Model shutdowns kept to notice (8). Support centre and dated notes (15). The sampled SDK issue without a reply, per the 1 October check (5 of 10). Current SDKs (15). Runtimes stated (10). 30 + 8 + 8 + 15 + 5 + 15 + 10 = 91.

Tencent Hy4 73

Model reading for hy4 on Tencent Cloud TokenHub. Platform facts are the tencent-tokenhub listing's (checked 1 November), carried over as RULES.md allows for a model on an already graded platform. Added on 4 November 2026 per the release notes; the model list and price page were updated on 9 November (30). Retirement notices of 21 to 33 days, no minimum written (7 of 12). Heavy retirement churn on the platform (3 of 8). Dated release notes and announcements, round-the-clock support (13 of 15). CLI replies not sampled (3 of 10). Control-plane SDKs and CLI, no inference SDK of its own (12 of 15). CLI runtime stated, CI not checked (5 of 10). 30 + 7 + 3 + 13 + 3 + 12 + 5 = 73. The model is a week old, so these lines are TokenHub's habits more than Hy4's record.

Schema & documentation Claude Mythos 5.2 +17

Claude Mythos 5.2 90

Model reading for claude-mythos-5-2 on the Claude API. Platform facts are the Claude API listing's (anthropic-api, re-read 1 November), carried over as RULES.md allows for a model on an already graded platform. The SDK-bundled OpenAPI file as half a contract (15 of 25, the Claude API listing's judgement call). llms.txt with Markdown twins (10). The model page, what's new and the migration guide say what changed from Fable 5.1 and what to send and not send (forced tool choice, sampling parameters, computer_20251124 returning 400 except on Bedrock), read 9 November (20). Structured outputs and strict tools GA (15). Documented error types with request_id (15). anthropic-version and dated release notes (15). 15 + 10 + 20 + 15 + 15 + 15 = 90.

Tencent Hy4 73

Model reading for hy4 on Tencent Cloud TokenHub. Platform facts are the tencent-tokenhub listing's (checked 1 November), carried over as RULES.md allows for a model on an already graded platform. No OpenAPI file for inference; field pages for the OpenAI and Anthropic formats as TokenHub implements them (12 of 25). llms.txt with Markdown copies (10). The model list, updated 9 November, gives hy4's context, input and output limits and marks thinking, structured output, function calling, caching and image understanding; computer use, which Tencent's release names, isn't marked (13 of 20). Typed field pages (10 of 15). Examples in five languages and an error page of 30 codes (14 of 15). Dated release notes, with hy4 added on 4 November (14 of 15). 12 + 10 + 13 + 10 + 14 + 14 = 73.

Payments & pricing Tencent Hy4 +15

Claude Mythos 5.2 30

Model reading for claude-mythos-5-2 on the Claude API. Platform facts are the Claude API listing's (anthropic-api, re-read 1 November), carried over as RULES.md allows for a model on an already graded platform. No machine payment protocol on the pricing page, read 9 November (0). Per-token prices published without a login, $8 and $40, the same as Fable 5.2 (20). The new-user free credit doesn't open this model, since it's available only to organisations verified through Anthropic's programmes (0, a judgement call; Fable 5.2 keeps the Claude API's 10). Keys from the browser Console only, and verification is an application Anthropic decides (0). 0 + 20 + 0 + 0 = 20. Re-scored on 13 November 2026 for the new payments rubric (protocol 10, the other three lines 30 each): 20 is 30.

Tencent Hy4 45

Model reading for hy4 on Tencent Cloud TokenHub. Platform facts are the tencent-tokenhub listing's (checked 1 November), carried over as RULES.md allows for a model on an already graded platform. No machine payment protocol (0). The price page, updated 9 November, lists ¥6 input, ¥0.3 cached and ¥18 output per million tokens, with Hy4 billed at 50% until 31 December 2026 (20). TokenHub's campaign of 1M free tokens per language model, read on 1 November, isn't confirmed for hy4 on the price page, so half (10 of 20, a judgement call). A person signs up with real-name verification (0). 0 + 20 + 10 + 0 = 30. Re-scored on 13 November 2026 for the new payments rubric (protocol 10, the other three lines 30 each): 30 is 45.

Reliability Claude Mythos 5.2 +14

Claude Mythos 5.2 60

Model reading for claude-mythos-5-2 on the Claude API. Platform facts are the Claude API listing's (anthropic-api, re-read 1 November), carried over as RULES.md allows for a model on an already graded platform. Status page at status.claude.com with component history (20). The last 90 days carry several major and two critical API incidents, among them Fable 5.1 and Mythos 5.1 on 3 September and Fable 5.1 on 23 and 25 October, so 0 for incident history. Rate limits published per model, Fable 5.x at 4,000 requests a minute at the Start tier (15). 429s with retry-after and SDK retries with backoff (15). No SLA on sale (0). The model page lists it as a current model with no preview label (10). 20 + 0 + 15 + 15 + 0 + 10 = 60. Graded by an agent running on Claude, by the same checklist as every other listing.

Tencent Hy4 46

Model reading for hy4 on Tencent Cloud TokenHub. Platform facts are the tencent-tokenhub listing's (checked 1 November), carried over as RULES.md allows for a model on an already graded platform. No public status page (0) and so no incident record to read (5 of 30). Per-model rate limits only in the console and DescribeModelQuota (8 of 15). Six 429 codes, Retry-After and backoff advice (13 of 15). The TokenHub SLA promises 99.5% a month, and Hy4 is Tencent's own model, so the third-party exclusion doesn't apply (10). Released as hy4 on 4 November, a separate id from hy4-preview, with no preview label (10). 0 + 5 + 8 + 13 + 10 + 10 = 46.

Score by category

CategoryWeight this runClaude Mythos 5.2Tencent Hy4Edge
Reliability16%206046Claude Mythos 5.2 +14
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.29073Claude Mythos 5.2 +17
Agent ergonomics13%16.29586Claude Mythos 5.2 +9
Security & auth14%17.59271Claude Mythos 5.2 +21
Payments & pricing10%12.53045Tencent Hy4 +15
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.89173Claude Mythos 5.2 +18
Transparency & trust7%8.88552Claude Mythos 5.2 +33
Negative events≤1500
TotalBB 77.3/100B 64/100

Facts side by side

FactClaude Mythos 5.2Tencent Hy4
KindModel APIModel API
VendorAnthropicTencent (Hy team)
Hosted endpointhttps://api.anthropic.com/v1no (local only)
TransportsHTTP
AuthAPI keyAPI key
PricingPay per usePay per use
x402nono
LicenceClosed model, used through the Claude API and cloud platforms under Anthropic's Commercial Terms of ServiceHosted model under the Tencent Cloud TokenHub terms. Tencent says weights and a system card will follow; no licence is stated yet
Read-only variant documentednono
llms.txtyesyes
Last release2026-11-092026-11-04
Terms last updatedno date givencouldn't be read
Privacy policy last updatedno date givencouldn't be read
Customer content may train modelsyes, with an opt-outcouldn't be read
Terms restrict automated accessnot found in the textcouldn't be read
Terms restrict benchmarkingyescouldn't be read
Terms or service can change without noticenot found in the textcouldn't be read
Arbitration or class-action waiveryescouldn't be read

How the scores have moved

Verdicts

Claude Mythos 5.2

Fable 5.2 without Fable's stronger cyber and biology safeguards, for verified security and life-science teams, on the same mature API at $8 and $40 per million tokens. Most agents can't use it, since access depends on Anthropic approving the organisation, and it requires 30-day retention.

Tencent Hy4

Tencent's flagship model is on TokenHub as hy4, with a 1M-token context, image understanding, function calling and caching, at ¥6 input and ¥18 output per million tokens, half price until the end of 2026. The weights it is called open source for aren't published yet, and every benchmark is Tencent's own.

Before you call either

Claude Mythos 5.2

  1. Confirm your organisation is verified before routing work here; otherwise use claude-fable-5-2
  2. Call https://api.anthropic.com/v1/messages with model claude-mythos-5-2 and your key
  3. Steer thinking with the effort parameter (default high); don't send temperature, top_p or top_k
  4. Don't force a tool with tool_choice any or tool; describe the tool and let the model choose
  5. Thinking blocks from it are read only by Fable 5.2 and Mythos 5.2, so keep them out of other models' context
  6. Check data retention before sending regulated data, since 30 days is required

Tencent Hy4

  1. Use model id hy4 on TokenHub's OpenAI- or Anthropic-compatible endpoints; hy4-preview is a separate, older model
  2. Keep input under 960K tokens and expect at most 64K output
  3. Reuse prompt prefixes: cached input is ¥0.3 against ¥6
  4. Check the price page for the end of the 50% discount on 31 December 2026 before budgeting
  5. Read rate limits from the console or DescribeModelQuota; the public docs don't give them for chat models

Questions

Which is better for AI agents, Claude Mythos 5.2 or Tencent Hy4?

Claude Mythos 5.2 scores 77.3 (BB) on agent readiness against Tencent Hy4's 64 (B), and leads in 6 of 7 scored categories. Tencent Hy4 leads on payments & pricing.

Do Claude Mythos 5.2 and Tencent Hy4 need an API key?

Both need an API key.

Can an agent call Claude Mythos 5.2 and Tencent Hy4 without installing anything?

Claude Mythos 5.2 has a hosted endpoint at https://api.anthropic.com/v1. No hosted endpoint is listed for Tencent Hy4.

Other comparisons with Claude Mythos 5.2 or Tencent Hy4

Disclosure

Anthropic makes the models this research run and the review panel run on. This listing was graded by an agent running on Claude, by the same published checklist as every other listing, from Anthropic's own pages and the Claude API listing's platform readings, with every judgement call written in the note. The panel reviews Anthropic's listings at our founder's request, and every review carries a conflict label, because every reviewer and the arbiter run on Claude.

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