Anthropic

Claude Opus 5.5

anthropic/claude-opus-5.5
Released Sep 22, 2026Commercial
ThinkingToolsVisioncommercial cloud

Claude Opus 5.5 is Anthropic's flagship model for demanding reasoning, coding, and long-horizon agentic work, succeeding Claude Opus 5. It is particularly strong at multi-step changes in large codebases, code...

Cost / 1M tokens

High usage

$4.00

input

$0.20

cached input

$20.00

output

Context Window

1M

Up to 128K max output

Modalities

text, image, file → text

Claude tokenizer

Quickstart & API

anthropic/claude-opus-5.5
Open the model picker in ChatOSS Desktop (Code, Kanban, or Chat) and select or paste this model ID.

Best for & Strengths

Key Strengths

#1 ChatOSS Agentic Coding Index74.2% DeepSWE v1.165.2% Terminal-Bench 4.090.3% Vibe Code Bench

Recommended Workloads in ChatOSS

  • Mission-critical architecture
  • Multi-repo code migrations
  • Hardest debugging sessions
Available in ChatOSS Code, Kanban Orchestrate, and Chat modes via Plus, Max, or BYOK.

Verified Evaluations

Benchmarks & Frontier Comparison

How Claude Opus 5.5 compares against leading open-weight and proprietary frontier models across independent agentic coding and reasoning suites.

View full Top 40 Leaderboard →
Claude Opus 5.5DeepSeek V4.1 FlashGLM 5.3Kimi K3.1 Pro
Benchmark (Metric)Claude Opus 5.5DeepSeek V4.1 FlashGLM 5.3Kimi K3.1 ProGemini 4 Argon
Agentic & Software Engineering
ChatOSS Agentic Coding Index (%)74.1%63.2%58.3%65%73.9%
SWE-Bench Verified (%)97%91.5%95.4%94.8%94%
DeepSWE v1.1 (Pass@1 %)74.2%77%69%73.5%77.9%
Vibe Code Bench v1.1 (%)90.29%87.7%78.1%88.4%91.9%
Terminal-Bench 4.0 (%)65.15%42.3%42%46.2%57.6%
Code Migration (%)66.65%45.6%44.2%52%68.2%
Intelligence & Token Economics
Artificial Analysis Intelligence Index (0–100)59.139.544.855.152.6
Input Price (/ 1M tokens)$4.00$0.15$1.40$2.00$4.00
Output Price (/ 1M tokens)$20.00$0.60$4.40$10.00$20.00

ChatOSS Agentic Coding Index

ChatOSS Benchmark Audit · 4-benchmark composite mean

74.1%

SWE-Bench Verified

Vals AI · Terminus 2

97%

DeepSWE v1.1

DeepSWE / Official Audit · Mini-SWE-Agent

74.2%

Vibe Code Bench v1.1

Vals.ai · OpenHands

90.29%

Terminal-Bench 4.0

Vals.ai / Artificial Analysis · Terminus 2

65.15%

Terminal-Bench 2.1

Vals.ai · Terminus 2

84.64%

Code Migration

Vals.ai · Vals evaluation harness

66.65%

Artificial Analysis Intelligence Index

Artificial Analysis

59.1

GPQA Diamond (Pass@1)

Benchmark Audit

93.8%

Humanity's Last Exam (Pass@1)

Artificial Analysis / Audit

56.3%

Design Arena: ANDROIDNATIVE

Design Arena · Rank #1 (76.7% win)

1405 Elo

Design Arena: BLENDER3D

Design Arena · Rank #4 (57.2% win)

1258 Elo

Design Arena: CODETOVIDEO

Design Arena · Rank #1 (74.5% win)

1343 Elo

Design Arena: FULLSTACK

Design Arena · Rank #1 (72% win)

1399 Elo

Active Provider Endpoints (11)

Upstream inference providers serving Claude Opus 5.5, with per-provider pricing, context limits, quantization, and 24-hour uptime.

ProviderInput / 1MOutput / 1MCache Read / 1MContextMax OutputQuantizationUptime (24h)
Amazon Bedrock
amazon-bedrock
$4.00$20.00$0.201M128K—100.0%
Azure
azure/global
$4.00$20.00$0.201M128K—100.0%
Google
google-vertex/global
$4.00$20.00$0.201M128K—100.0%
Claude Platform on AWS
claude-on-aws
$4.00$20.00$0.201M128K—100.0%
Anthropic
anthropic
$4.00$20.00$0.201M128K—100.0%
Amazon Bedrock
amazon-bedrock/eu-west-1
$4.40$22.00$0.221M128K—100.0%
Amazon Bedrock
amazon-bedrock/us-east-1
$4.40$22.00$0.221M128K—100.0%
Azure
azure/us
$4.40$22.00$0.221M128K——
Google
google-vertex/us
$4.40$22.00$0.221M128K—100.0%
Google
google-vertex/europe
$4.40$22.00$0.221M128K—100.0%
Anthropic
anthropic/fast
$8.00$40.00$0.401M128K—100.0%

Supported API Parameters

Parameters accepted by this model when called through ChatOSS or OpenRouter.

include_reasoningmax_completion_tokensmax_tokensreasoningreasoning_effortresponse_formatstopstructured_outputstool_choicetoolsverbosity

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