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AnthropicModel API

Claude Opus 4.5 API

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MODEL IDclaude-opus-4.5
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01 / OVERVIEW

Claude Opus 4.5
overview.

Claude Opus 4.5 is an earlier Anthropic Opus release with a smaller published context window than Opus 4.6 and the later entries. Its evaluation uses the Reasoning label rather than the Max labels shown for those releases. Use this entry’s own specifications and model ID when comparing an existing integration with a newer Opus model.

Published model specifications

Context window200k tokens
ReasoningSupported
Inputtext & image
Outputtext
AA Intelligence Index29* / v4.3.2
Catalog release24 Nov 2025
Source: Artificial Analysis ↗
OPTIONAL / CONNECTIONAPI request example

Set the model ID and base URL in your OpenAI-compatible client.

BASE URL
https://aelder.dev/v1
API documentation ↗

Compare Claude model prices or follow the Python and JavaScript SDK setup.

import os
from openai import OpenAI

client = OpenAI(
    api_key=os.environ["AELDER_API_KEY"],
    base_url="https://aelder.dev/v1",
)

response = client.chat.completions.create(
    model="claude-opus-4.5",
    messages=[{"role": "user", "content": "Hello!"}],
)

print(response.choices[0].message.content)
MODELclaude-opus-4.5Chat Completions
02 / MODEL BENCHMARKS

Claude Opus 4.5 benchmarks.

Compare models in the AELDER catalog on the same external measure. The Artificial Analysis Intelligence Index combines evaluations of model capability. Higher is better; the score is not a percentage.

Artificial Analysis Intelligence Index

VERSION 4.3.2 · INDEX POINTS · HIGHER IS BETTER
Claude Opus 4.529*
41 scored catalog models
Catalog models and their external Artificial Analysis evaluation configurations
ModelSource configurationIndex
Claude Opus 5.5Claude Opus 5.5 (Max, Default Fallback)58
Claude Sonnet 5.5Claude Sonnet 5.5 (Max, Default Fallback)56
Claude Fable 5.1Claude Fable 5.1 (Max, Default Fallback)53
GPT 6 AstraGPT-6 Astra (Max)53
GPT 6.1 SolGPT-6.1 Sol (Max)52
Claude Opus 5Claude Opus 5 (Max)51
Claude Fable 5Claude Fable 5 (Max, Opus 4.8 Fallback)50
GPT 6 SolGPT-6 Sol (Max)48
GPT 5.6 SolGPT-5.6 Sol (Max)47
DeepSeek V4.1 FlashDeepSeek V4.1 Flash 1017 (Max)45
GLM 5.3GLM-5.3 (Max)45
Qwen3.8 Max 0902Qwen3.8 Max (0902)45
Grok 4.6Grok 4.6 (Xhigh)44
Kimi K3Kimi K3 (Max)44
Claude Haiku 5.5Claude Haiku 5.5 (Max)43
Claude Opus 4.8Claude Opus 4.8 (Max)42
GLM 5.3 FlashGLM-5.3-Flash42
GPT 5.6 TerraGPT-5.6 Terra (Max)42
Claude Opus 4.7 (1M)Claude Opus 4.7 (Max)41*
Gemini 3.8 FlashGemini 3.8 Flash (High)41
Qwen3.8 2.4T-A95BQwen3.8 2.4T A95B40
Qwen3.8 MaxQwen3.8 Max40
Claude Sonnet 5Claude Sonnet 5 (Max)38
GPT 6 LunaGPT-6 Luna (Max)38
GPT 5.6 LunaGPT-5.6 Luna (Max)37
DeepSeek V4 ProDeepSeek V4 Pro 0813 (Max)36
GLM 5.2GLM-5.2 (Max)34
Qwen3.8 27BQwen3.8 27B (Xhigh)34
GPT 5.3 CodexGPT-5.3 Codex (Xhigh)33*
Claude Opus 4.6Claude Opus 4.6 (Max)32*
Claude Sonnet 4.6Claude Sonnet 4.6 (Max)30
Gemini 3.1 ProGemini 3.1 Pro Preview30
Claude Opus 4.5CurrentClaude Opus 4.5 (Reasoning)29*
MiniMax M3MiniMax-M329
Kimi K2.6Kimi K2.6 (Reasoning)27
GLM 5.1GLM-5.1 (Reasoning)26
Kimi K2.7 CodeKimi K2.7 Code26
Hy3Hy325
DeepSeek V4 FlashDeepSeek V4 Flash 0420 (Max) · April 2026 reference24
Kimi K2.5Kimi K2.5 (Reasoning)23*
MiniMax M2.7MiniMax-M2.723
Current modelScroll to explore all models →Sources checked 21 Oct 2026

DeepSeek V4 Flash uses the April 0420 release reference, labelled in the chart and table. External results refer to the labelled source configurations, which may differ from AELDER’s configuration. They do not measure AELDER API speed or uptime. Source score markers (*) are preserved.

Why are 4 catalog models missing a score?

41 of 45 catalog models have a source reference on this index version. A missing result is not a zero score. These models remain in the catalog.

KEEP EXPLORING

Claude Opus 4.5 alternatives.

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MODEL DETAILS

Claude Opus 4.5
questions, answered.

Does the AELDER model ID need the publisher’s dated suffix?
Use claude-opus-4.5, exactly as shown in the API example on this page. Model identifiers belong to the API service you call; do not replace this ID with a dated publisher ID unless the service documents it.
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