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model

claude-sonnet-4-5

Claude Sonnet 4.5 is a large language model in Anthropic's Claude family, used via API for tasks like text classification, reasoning, and agentic workflows.

Known aliases

  • Anthropic Claude Sonnet 4.5
  • Claude 4.5 Sonnet
  • Claude Sonnet 4.5
  • claude-sonnet-4-5
  • Claude-Sonnet-4.5
  • claude-sonnet-4-5-20250929
  • global.anthropic.claude-sonnet-4-5-20250929-v1:0
  • Sonnet 4.5

Relationships

No evidence-backed relationships are recorded.

Current stories

build1 publisher

Anthropic prices its newer Sonnet a third below Sonnet 4.5

Sonnet 4.5 still leads GPT-5 on the coding leaderboards, and GPT-5 lists about 46 percent below it on a 5:1 token mix. Anthropic's current Sonnet undercuts both of Sonnet 4.5's list prices, and that complicates a routing plan built on the older pair.

Publishers:dev.to

Reality

Evidence40
Adoption20
Hype gap+15
Incentives55
Confidence45

Earlier coverage

  1. A "security simulation" alibi walked Cursor's agent past its own refusals

    Build · August 28, 2026 · 2 publishers

  2. A model documenting a retry wrapper hands you tenacity's parameters

    Build · August 27, 2026 · 1 publisher

  3. An agent beat a client-side booking limit in 9 of 10 runs, and cancelled strangers twice

    Security · August 26, 2026 · 1 publisher

  4. Junie Local is free. The 64 GB M5 Mac is the price.

    Build · August 24, 2026 · 2 publishers

  5. If you can draw the flowchart before the run, you did not need the agent loop

    Build · August 22, 2026 · 1 publisher

  6. The cheapest model scored 10 out of 100: assistant choice is now a code-security decision

    Product · August 19, 2026 · 1 publisher

  7. Anthropic streams tool arguments as JSON fragments, so pick a coping strategy on purpose

    Build · August 18, 2026 · 1 publisher

  8. The refund button is the architecture: inside the tool-use layer of a support agent

    Build · August 16, 2026 · 1 publisher