Head to head · LLM inference · October 2026 research run
Claude Mythos 5.2 vs SWE-2 Flash
Claude Mythos 5.2 scores 76.1 (BB) on agent readiness against SWE-2 Flash's 36.4 (F), and leads in 6 of 7 scored categories. Both do llm inference.
Best model APIs and inference for AI agents · All 956 models comparisons
Which one, for what
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 50
- Schema & documentation, 90 against 29
- Agent ergonomics, 95 against 10
- Security & auth, 92 against 53
- Maintenance & community, 91 against 53
- Transparency & trust, 85 against 64
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
Best for People already using Devin Desktop or Devin CLI who want a cheaper, faster model for routine coding work such as automations, reviews and small changes, while it is free in November 2026.
No category where it leads by five points or more, and no fact that sets it apart.
Watch for
No model API, OpenAPI entry or model card. The Devin API's session agents list SWE-2 but not SWE-2 Flash
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.
Agent ergonomics Claude Mythos 5.2 +85
Claude Mythos 5.2 95
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. Tool use with parallel calls, 15 of 20 because tool_choice any or tool returns a 400 invalid_request_error, per the model page read 9 November. Structured outputs (15). Prompt caching with reads at $0.20, 0.025x input, per the pricing page read 9 November (15). 1M context by default and at most, 128K output (15). Batch at half price (10). Official SDKs in seven languages (10). Documented errors, retry-after and retries (15). 15 + 15 + 15 + 15 + 10 + 10 + 15 = 95.
SWE-2 Flash 10
Model reading (tool use, structured output, caching, context, batch, SDKs). Tool use is Devin's harness, not something a caller configures; no context length, output limit or cache price is published for SWE-2 Flash (5 of 25). No documented output-size or reasoning controls for this model; SWE-2's effort levels aren't stated for Flash (0 of 20). No model-level error documentation (0 of 20). No idempotency or retry guidance (0 of 20). One flag or picker selects it and devin -p runs a single turn and prints to stdout, but there is no SDK or direct endpoint (5 of 15). 5 + 0 + 0 + 0 + 5 = 10.
Schema & documentation Claude Mythos 5.2 +61
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.
SWE-2 Flash 29
Model reading. No model API, so no OpenAPI entry; the Devin v3 OpenAPI file lists SWE-2 agents only, and no model card was found (0). docs.devin.ai serves llms.txt and Markdown copies of every page (10). The launch post says what it is for (automations, code review, feature development, documentation) and the CLI docs say when to pick a SWE model, but the models pages don't list SWE-2 Flash yet (6 of 20). No documented model ID, reasoning settings, context or output limits to type (0 of 15). The CLI pages show --model and /model examples, with no model-specific errors (3 of 15). Named, dated model versions on Cognition's blog and public release notes, but no release note for SWE-2 Flash yet; the newest is 2 November (10 of 15). 0 + 10 + 6 + 0 + 3 + 10 = 29.
Security & auth Claude Mythos 5.2 +39
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.
SWE-2 Flash 53
Read as a hosted model reached through Devin's local clients. The CLI signs in through a browser, or the enterprise identity provider, and stores an API token in credentials.toml that by default is persistent and does not expire and carries the user's access, with no scopes found for it (10 of 30). Devin CLI documents an OS-level sandbox with network filtering, hooks that can block tool calls, and enterprise model allowlists and team settings (14 of 20). Guardrails against prompt injection are Enterprise only and cover user messages, as on the devin listing (8 of 15). Enterprise analytics count tool calls and consumption by model and user; no per-user audit log for the CLI was found (8 of 15). SOC 2 Type II and ISO/IEC 27001:2022, a disclosure address, no bug bounty and no security.txt, per the devin listing (13 of 20). Training: self-serve customer data may train Cognition's models by default, with an opt-out on paid plans that also turns on zero data retention at model providers. Cognition withheld the weights over cyber misuse, which is recorded as a fact, not scored. 10 + 14 + 8 + 8 + 13 = 53.
Maintenance & community Claude Mythos 5.2 +38
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.
SWE-2 Flash 53
Model reading. Released 4 November 2026 (30). Churn and notice in place of release counts: SWE-1.6, SWE-1.7, SWE-1.7 Lightning, SWE-2 (10 September) and now SWE-2 Flash in a few months, with no model deprecation notice period found and short names that move to the newest model (10 of 20). Public release notes and a support address, no public tracker (10 of 25). No official SDK for the model (0 of 15). The docs are kept current but don't yet cover this model (3 of 10). 30 + 10 + 10 + 0 + 3 = 53.
Transparency & trust Claude Mythos 5.2 +21
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.
SWE-2 Flash 64
Editorial half. Closed model under Cognition's platform terms; the weights aren't public and the sharing programme isn't described yet (15). Terms, privacy policy, security page and DPA agree, with training on self-serve data by default and no retention periods, as read for the devin listing (18). The API versioning policy covers API endpoints, not models, and no model deprecation notice was found (5 of 20). Sub-processors listed with purpose and country, per the devin listing's 8 October check (18). 15 + 18 + 5 + 18 = 56.
Reliability Claude Mythos 5.2 +10
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.
SWE-2 Flash 50
Model reading, for the surface it runs on, Devin Desktop and Devin CLI. Status page at www.devinstatus.com (Atlassian Statuspage) with Desktop Agent and Desktop Tab components besides the cloud ones, read on 4 November 2026 (20). The history feed for the 90 days from 6 August lists 'Devin unavailable' for 20 minutes on 13 August with no component named, read as across the board and a major as on the devin listing; Devin Cloud unavailable on 13 August and the web app down on 24 September name cloud surfaces this model doesn't use; the rest are degraded-performance incidents (new sessions on 3 September, 'multiple services' on 17 September, Ask Devin on 26 October, automation triggers on 4 November) and session queuing on 10 and 11 August, read as minor and a scheduled Devin Desktop extension marketplace upgrade on 7 August, read as maintenance. One major (10). No rate limit figures for the model or the CLI; usage is a daily and weekly quota with no numbers (0). No 429, backoff or retry guidance for this surface (0). Cognition publishes an SLA (25 February 2026) with uptime and response times that applies when included in an order form, read as a contractual SLA on Enterprise, as on other listings (10). The launch post makes it available today with no preview or beta label (10). 20 + 10 + 0 + 0 + 10 + 10 = 50.
Score by category
| Category | Weight this run | Claude Mythos 5.2 | SWE-2 Flash | Edge |
|---|---|---|---|---|
| Reliability | 16%20 | 60 | 50 | Claude Mythos 5.2 +10 |
| Performance | 10%pending | pending | pending | not scored in this run |
| Schema & documentation | 13%16.2 | 90 | 29 | Claude Mythos 5.2 +61 |
| Agent ergonomics | 13%16.2 | 95 | 10 | Claude Mythos 5.2 +85 |
| Security & auth | 14%17.5 | 92 | 53 | Claude Mythos 5.2 +39 |
| Payments & pricing | 10%12.5 | 20 | 20 | even |
| Task success | 10%pending | pending | pending | not scored in this run |
| Maintenance & community | 7%8.8 | 91 | 53 | Claude Mythos 5.2 +38 |
| Transparency & trust | 7%8.8 | 85 | 64 | Claude Mythos 5.2 +21 |
| Negative events | ≤15 | 0 | -2 | |
| Total | BB 76.1/100 | F 36.4/100 |
Facts side by side
| Fact | Claude Mythos 5.2 | SWE-2 Flash |
|---|---|---|
| Kind | Model API | Model API |
| Vendor | Anthropic | Cognition AI, Inc. |
| Hosted endpoint | https://api.anthropic.com/v1 | no (local only) |
| Transports | ||
| Auth | API key | OAuth or key |
| Pricing | Pay per use | Freemium |
| x402 | no | no |
| Licence | Closed model, used through the Claude API and cloud platforms under Anthropic's Commercial Terms of Service | Proprietary model, used through Devin Desktop and Devin CLI under Cognition's Platform Terms of Service. The weights are not public; Cognition says it is building a programme to share them with industry partners and researchers |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-11-09 | 2026-11-04 |
| Terms last updated | no date given | 2026-06-30 |
| Privacy policy last updated | no date given | 2026-03-09 |
| Customer content may train models | yes, with an opt-out | yes, with an opt-out |
| Terms restrict automated access | not found in the text | not found in the text |
| Terms restrict benchmarking | yes | yes |
| Terms or service can change without notice | not found in the text | not found in the text |
| Arbitration or class-action waiver | yes | yes |
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.
SWE-2 Flash
A new small coding model from Cognition that anyone can try free in Devin Desktop and Devin CLI until 30 November 2026, with strong vendor-reported coding scores. It has no model API, no published per-token price, context length or model card, and no public weights, so an agent can reach it only by driving Devin's own CLI.
Before you call either
Claude Mythos 5.2
- Confirm your organisation is verified before routing work here; otherwise use claude-fable-5-2
- Call https://api.anthropic.com/v1/messages with model claude-mythos-5-2 and your key
- Steer thinking with the effort parameter (default high); don't send temperature, top_p or top_k
- Don't force a tool with tool_choice any or tool; describe the tool and let the model choose
- Thinking blocks from it are read only by Fable 5.2 and Mythos 5.2, so keep them out of other models' context
- Check data retention before sending regulated data, since 30 days is required
SWE-2 Flash
- There is no endpoint to call. Run Devin CLI single-turn with
devin -pand pick the model with--model; the SWE-2 Flash model ID isn't documented yet, so check/modelin the CLI first - Don't rely on the short name
swe. The docs say it resolves to the latest model in the family, which may be SWE-2 rather than SWE-2 Flash - Plan for billing to start on 1 December 2026. The free period covers Devin Desktop and CLI only, not Devin cloud sessions
- Treat Cognition's benchmark figures as the vendor's. No independent result for SWE-2 Flash was found
- Keep
credentials.tomlprivate. The token in it doesn't expire by default and carries the signed-in user's access
Questions
Which is better for AI agents, Claude Mythos 5.2 or SWE-2 Flash?
Claude Mythos 5.2 scores 76.1 (BB) on agent readiness against SWE-2 Flash's 36.4 (F), and leads in 6 of 7 scored categories.
Do Claude Mythos 5.2 and SWE-2 Flash need an API key?
Claude Mythos 5.2 needs an API key. SWE-2 Flash takes an API key or an OAuth sign-in.
Can an agent call Claude Mythos 5.2 and SWE-2 Flash without installing anything?
Claude Mythos 5.2 has a hosted endpoint at https://api.anthropic.com/v1. No hosted endpoint is listed for SWE-2 Flash.
Other comparisons with Claude Mythos 5.2 or SWE-2 Flash
- Amazon Bedrock vs Claude Mythos 5.2
- Amazon Bedrock vs SWE-2 Flash
- Claude API vs Claude Mythos 5.2
- Claude API vs SWE-2 Flash
- Antseed vs Claude Mythos 5.2
- Antseed vs SWE-2 Flash
- Azure OpenAI in Foundry Models vs Claude Mythos 5.2
- Azure OpenAI in Foundry Models vs SWE-2 Flash
- BlockRun.AI vs Claude Mythos 5.2
- BlockRun.AI vs SWE-2 Flash
- Cerebras Inference vs Claude Mythos 5.2
- Cerebras Inference vs SWE-2 Flash
- Claude Fable 5.2 vs Claude Mythos 5.2
- Claude Fable 5.2 vs SWE-2 Flash
- Claude Mythos 5.2 vs Cloudflare AI Gateway
- Claude Mythos 5.2 vs Cloudflare Workers AI
- Claude Mythos 5.2 vs Cohere Chat API (Command models)
- Claude Mythos 5.2 vs DeepInfra
- Claude Mythos 5.2 vs DeepSeek API
- Claude Mythos 5.2 vs Eden AI
- Claude Mythos 5.2 vs Glimpse
- Claude Mythos 5.2 vs Fireworks AI Inference
- Claude Mythos 5.2 vs Gemini Developer API
- Claude Mythos 5.2 vs GroqCloud
- Claude Mythos 5.2 vs Hugging Face Inference Providers
- Claude Mythos 5.2 vs Inkling 2 Small
- Claude Mythos 5.2 vs Jais 3
- Claude Mythos 5.2 vs Meta Model API
- Claude Mythos 5.2 vs MiniMax API
- Claude Mythos 5.2 vs Mistral AI API
- Claude Mythos 5.2 vs Muse Ember
- Claude Mythos 5.2 vs Muse Spark Open
- Claude Mythos 5.2 vs Nemotron 3.5 Super VL
- Claude Mythos 5.2 vs Novita AI
- Claude Mythos 5.2 vs OpenAI API
- Claude Mythos 5.2 vs OpenRouter
- Claude Mythos 5.2 vs Prism Inference
- Claude Mythos 5.2 vs Router.com (Ramp Router)
- Claude Mythos 5.2 vs Beam 1.0
- Claude Mythos 5.2 vs RouterPlus
- Claude Mythos 5.2 vs SambaCloud
- Claude Mythos 5.2 vs SiliconFlow
- Claude Mythos 5.2 vs Simplismart
- Claude Mythos 5.2 vs StepFun API
- Claude Mythos 5.2 vs Tencent Cloud TokenHub
- Claude Mythos 5.2 vs Together AI Inference
- Claude Mythos 5.2 vs Vercel AI Gateway
- Claude Mythos 5.2 vs Vertex AI (Gemini Enterprise Agent Platform)
- Claude Mythos 5.2 vs xAI API (Grok)
- Cloudflare AI Gateway vs SWE-2 Flash
- Cloudflare Workers AI vs SWE-2 Flash
- Cohere Chat API (Command models) vs SWE-2 Flash
- DeepInfra vs SWE-2 Flash
- DeepSeek API vs SWE-2 Flash
- Eden AI vs SWE-2 Flash
- Glimpse vs SWE-2 Flash
- Fireworks AI Inference vs SWE-2 Flash
- Gemini Developer API vs SWE-2 Flash
- GroqCloud vs SWE-2 Flash
- Hugging Face Inference Providers vs SWE-2 Flash
- Inkling 2 Small vs SWE-2 Flash
- Jais 3 vs SWE-2 Flash
- Meta Model API vs SWE-2 Flash
- MiniMax API vs SWE-2 Flash
- Mistral AI API vs SWE-2 Flash
- Muse Ember vs SWE-2 Flash
- Muse Spark Open vs SWE-2 Flash
- Nemotron 3.5 Super VL vs SWE-2 Flash
- Novita AI vs SWE-2 Flash
- OpenAI API vs SWE-2 Flash
- OpenRouter vs SWE-2 Flash
- Prism Inference vs SWE-2 Flash
- Router.com (Ramp Router) vs SWE-2 Flash
- Beam 1.0 vs SWE-2 Flash
- RouterPlus vs SWE-2 Flash
- SambaCloud vs SWE-2 Flash
- SiliconFlow vs SWE-2 Flash
- Simplismart vs SWE-2 Flash
- StepFun API vs SWE-2 Flash
- SWE-2 Flash vs Tencent Cloud TokenHub
- SWE-2 Flash vs Together AI Inference
- SWE-2 Flash vs Vercel AI Gateway
- SWE-2 Flash vs Vertex AI (Gemini Enterprise Agent Platform)
- SWE-2 Flash vs xAI API (Grok)
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.
Machine-readable
- This page as Markdown
/compare/claude-mythos-5-2-vs-swe-2-flash.md· slim.min.md· JSON.json(or sendAccept: text/markdown) - Each listing in full
/api/v1/tools/claude-mythos-5-2.json·/api/v1/tools/swe-2-flash.json - From a terminal
anchor compare claude-mythos-5-2 swe-2-flash(the CLI) - Over MCP
compare_tools {"a": "claude-mythos-5-2", "b": "swe-2-flash"}at/mcp, no key