Claude Opus 5 API

Access Anthropic Claude Opus 5—also searched as Opus 5— through EvoLink's unified chat API. Test long-context coding, tool use, prompt caching before integrating.

AnthropicText GenerationAvailable

From $4.750 / 1M input tokens$5.000 official price-5%

API docs

Extended thinkingTool usePrompt cachingWeb search toolChat + Messages API

Production routeLive

Live

Context

1M context · 128K max output

Best For

Repository-scale coding, long-horizon agents, high-stakes review

Input

Text + images

Output

Text · JSON (structured output) · tool calls

Models Pricing Readme API

Choose Claude Opus 5

Anthropic’s previous Opus-tier flagship for the hardest coding, long-running agents, and judgment-heavy review. Five billing dimensions — input, cache write, cache read, output, and the web search tool — are metered separately.

Claude Opus 5

Anthropic Opus-tier flagship model

Selected

Model ID

claude-opus-5

Best for

Repository-scale software engineering, long-horizon agent runs with heavy tool use, high-stakes code review, and research or analysis work where a wrong answer costs more than a premium token rate.

Input

$4.750 / 1M-5%

323 cr / 1M$5.000official price

Cache write

$5.939 / 1M-5%

403.8 cr / 1M$6.250official price

Cache read

$0.475 / 1M-5%

32.3 cr / 1M$0.500official price

Output

$23.750 / 1M-5%

1615 cr / 1M$25.000official price

All rates are per 1M tokens, shown in USD and credits, and reflect your account's current pricing.

Claude Opus 5 pricing

Estimate what one Claude Opus 5 request costs before you integrate. The calculator uses your account's current rates, with official pricing as a reference.

Request calculator

Enter the token mix for one request and the number of successful tool calls.

Input tokensCache write tokensCache read tokensOutput tokensWeb search

Estimated request cost

Claude Opus 5

USD$0.012

Credits0.814

Official estimate $0.013 · save $0.0007 (5%)

Input tokens0.323 cr

Cache write tokens0 cr

Cache read tokens0.0065 cr

Output tokens0.4845 cr

Minimum charge: 0.01 credits per request.

Budget guide

Approximate requests using the current token mix.

Add credits

$10

About 798 requests

For quick testing

$50

About 4176 requests

For regular development

$100

About 8353 requests

For production evaluation

Server-side tool rates

Only successful server-side calls are billed per call; failed attempts have no tool fee, but tokens still apply.

Web search$0.010/ call0.68 cr / call

Claude Opus 5 API for the hardest coding and agent work

Call Anthropic’s previous Opus-tier flagship through EvoLink’s unified API at $4.750 / $23.750 per million input / output tokens. Includes a 1,000,000-token context window, 128K max output, prompt caching with separate write and read rates, and the per-search web search tool.

Claude Opus 5 is served on EvoLink under the model ID claude-opus-5 through Chat Completions · Anthropic Messages, with the same API key and balance you use for every other model. It offers a 1M context window and up to 128K output tokens, plus long-context coding, tool use, prompt caching.

Claude Opus 5 specs and capabilities

Numbers come from the EvoLink route configuration; capabilities are what the API exposes today.

Context window: 1M tokens
Max output: 128K tokens
Input: Text + images
Output: Text · JSON (structured output) · tool calls
Reasoning: Thinking mode (on by default)
Tool use: Function calling with multi-step tool sequences
Prompt caching: Cache write + cache read rates
Server-side tools: Web search, billed per successful call
Protocols: Chat Completions · Anthropic Messages
Model ID: claude-opus-5

Where Claude Opus 5 earns its premium rate

Opus-tier pricing only pays off when a task is hard enough that a better answer removes work downstream. Route to Opus 5 by the cost of being wrong, not by the cost per token.

Repository-scale software engineering

Inspect large codebases, trace dependencies across services, and plan multi-file changes while holding architectural constraints in one context. Measure accepted patches and review time rather than isolated snippet quality.

Long-horizon agents with heavy tool use

Multi-step orchestration, tool selection, and code execution over long runs, where a single wrong branch costs far more than the token difference. Replay complete assistant messages, tool-call IDs, arguments, and tool results across turns.

High-stakes review and analysis

Security review, migration planning, contract and research analysis, and anything where a confident wrong answer is expensive. The 1M-token window keeps the full evidence set in one place.

When another route is the better choice

Everyday coding, high-volume agents, classification, and latency-sensitive chat usually belong on Claude Sonnet 5. Claude Opus 4.8 carries a deeper discount on EvoLink and remains the cheaper Opus route when its answers are good enough.

Two ways to use Claude Opus 5: EvoLink API or Agent

Use the EvoLink API for product backends and batch jobs, or call Claude Opus 5 from Codex, Claude, or Gemini for coding and analysis workflows. Both paths share the same EvoLink API key, balance, model ID, and request history.

Option 1

Integrate with the EvoLink API

Best for: product backends, batch jobs, automated pipelines

Send OpenAI-compatible Chat Completions (or Anthropic Messages) requests to EvoLink and control the model ID, system prompt, output budget, tools, and structured output.

1Create an EvoLink API key in the console
2Point your OpenAI or Anthropic SDK at the EvoLink base URL and select the model ID shown above
3Send one representative request and read the usage field for input, cached, and output tokens
4Set max_tokens and retries per task; keep tool-call IDs and results across turns

Create EvoLink API Key

Option 2

Call it with an Agent

Best for: coding, review, and analysis tasks in Codex, Claude, and Gemini

Give the Agent the task, the inputs to include, and the acceptance criteria. It assembles the request, calls Claude Opus 5 through EvoLink, and returns the answer with token usage.

1Set EVOLINK_API_KEY in your local environment; never put it in code or a prompt
2Describe the task, the inputs to include, and the expected output format
3Ask the Agent to call Claude Opus 5 through EvoLink and show the request before sending
4Let the Agent report the answer, token usage, and any error body

Claude Opus 5 API code example and error handling

This example shows the shortest runnable request: an OpenAI-compatible Chat Completions call with a system prompt, a user message, and an output budget. Open the API tab for the complete parameter and response reference.

View complete API docs

cURL

curl -X POST https://api.evolink.ai/v1/chat/completions \
  -H "Authorization: Bearer $EVOLINK_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-opus-5",
    "messages": [
      { "role": "system", "content": "You are a senior engineer reviewing a pull request." },
      { "role": "user", "content": "Review this diff and list the blocking issues with file and line:\n<diff>" }
    ],
    "max_tokens": 8192,
    "temperature": 0.2
  }'

# Anthropic Messages is also available at /v1/messages with the same model
# ID.
# The response includes choices[0].message and a usage object
# (prompt_tokens, completion_tokens, and cache read / write tokens when
# caching applies).

Invalid request or unsupported parameter

Check the model ID, the messages array, and parameter ranges against the API reference; remove fields this route does not support.

Authentication or balance issue

Check the Authorization bearer token and confirm the available balance in the console.

Context length exceeded

Prompt tokens exceed the Claude Opus 5 context window. Trim or retrieve only the relevant evidence and reuse cached prefixes.

Rate limited (429)

Back off and retry with jitter; batch or queue requests instead of sending parallel bursts.

Content or tool call rejected

Review sensitive content, malformed tool-call arguments, and JSON schema mismatches before retrying.

Adopt Claude Opus 5 without replacing your model stack

Keep one EvoLink client and API key, route the hardest workloads to Opus 5, and retain tested alternatives for simpler or latency-sensitive traffic.

Use the existing compatible client flow

Point the client at EvoLink, authenticate with the same API key, and select claude-opus-5. Both the OpenAI-compatible Chat Completions endpoint and the Anthropic Messages endpoint work.

Low migration

Use the documented API model ID

The API route is claude-opus-5 on both protocols. The page URL and the model parameter are identical for this model.

ID checked

Structure prompts for cache reuse

Put the stable system prompt, repository instructions, and tool schemas at the front of the request so the expensive prefix is written once and read cheaply for the rest of the session.

Cost control

Route tasks by completed-task value

Compare success rate, retries, output tokens, cache hits, wall-clock time, and human correction against Claude Opus 4.8 and Sonnet 5 — not token price alone.

Evaluate

Prompt caching billed as two separate dimensions

Claude prompt caching charges a write price when a prefix is stored and a much lower read price when it is reused. Stable system prompts, repository instructions, and tool schemas pay the write once and then read cheaply across a long agent run.

1M-token context with a 128K max output

Keep connected code, specifications, documents, and agent state in one working context. Treat the limit as capacity rather than a target: retrieve relevant evidence, cache the stable prefix, and set task-appropriate output budgets.

Thinking and effort change latency and token use

Anthropic enables adaptive thinking by default on Opus 5, and the Claude API defaults effort to high. Before production, verify parameter support on the EvoLink endpoint you use and measure the actual response, output tokens, and latency. Do not treat max_tokens as a thinking budget.

Replay real workloads before shifting production traffic

The same per-token rate does not guarantee the same completed-task cost. Model behavior and tokenizer changes can alter billed tokens, retries, and tool paths, so compare success rate, total cost, and human correction on production samples before shifting traffic.

Claude Opus 5: five billing dimensions, metered separately

Claude Opus 5 does not bill as a single blended rate. Understanding which dimension a workload actually consumes is what makes an Opus-tier budget predictable.

Input and output tokens

The two dimensions every request touches: $4.750 per 1M input tokens and $23.750 per 1M output tokens on EvoLink, compared with Anthropic’s $5.000 and $25.000. Output dominates on generation-heavy work, so cap max_tokens by task complexity.

Cache write and cache read

Storing a prefix costs $5.939 per 1M tokens; reusing it costs $0.475 per 1M tokens. A stable system prompt, repository instructions, and tool schemas pay the write once and then read at the cache-read rate for the rest of the run.

Web search tool

Billed per search at $0.010. Search results also enter the request as ordinary input tokens, so a research-heavy turn pays both the per-search fee and the tokens it pulls in.

Compare Claude routes after workload testing

EvoLink

First verify whether Opus 5 reduces retries and review effort on your own tasks. Then compare price, context, caching, and workload fit to choose the production route.

Model	Claude Opus 5	Claude Opus 4.8	Claude Sonnet 5
Input / output	$4.75 / $23.75	$4.5 / $22.5	$1.8 / $9
Context	1M	1M	1M
Caching	Read + write	Read + write	Read + write
Best for	Repository-scale software engineering, long-horizon agent runs with heavy tool use, high-stakes code review, and research or analysis work where a wrong answer costs more than a premium token rate.	The previous Opus flagship, still the cheaper Opus route on EvoLink for premium coding and agent work.	Opus-class coding and agent performance at a balanced Sonnet rate for everyday production traffic.

Claude Opus 5

Input / output$4.75 / $23.75

Context1M

CachingRead + write

Best forRepository-scale software engineering, long-horizon agent runs with heavy tool use, high-stakes code review, and research or analysis work where a wrong answer costs more than a premium token rate.

Claude Opus 4.8

Input / output$4.5 / $22.5

Context1M

CachingRead + write

Best forThe previous Opus flagship, still the cheaper Opus route on EvoLink for premium coding and agent work.

Claude Sonnet 5

Input / output$1.8 / $9

Context1M

CachingRead + write

Best forOpus-class coding and agent performance at a balanced Sonnet rate for everyday production traffic.

Claude Model Family

Same API key and balance — switch tiers without changing your integration.

Compare all Claude models

Claude Haiku 5.5

The fastest, lowest-cost Claude route for sub-agents, high-volume classification, and low-latency chat.

View model

Claude Sonnet 5.5

Anthropic’s newest Sonnet for everyday coding and high-volume agents; compare it on your workload before routing traffic to an Opus model.

View model

Claude Opus 5.5

Anthropic’s newer Opus at a lower list price, with thinking always on; compare it on your own workload before moving traffic from Opus 5.

View model

Other text models on EvoLink besides Claude Opus 5

GPT-5.6

OpenAI’s tiered frontier family for routing across capability, latency, and cost.

View model

Grok 4.5

xAI’s reasoning and tool-use route with a 500K context window and server-side search tools.

View model

Kimi K3

A long-context reasoning model for repository-scale coding and multi-document work.

View model

Gemini 3.6 Flash

A fast, low-cost route for production traffic that does not need Opus-tier judgment.

View model

Claude Opus 5 guides and related reading

Claude Opus 5.5 vs Claude Opus 5

Opus 5 now has a cheaper successor. What changed, which requests break, and how to decide whether to keep Opus 5, pilot 5.5, or migrate.

Read guide

Claude Opus 6 Release Watch

Track the next Opus generation without treating its release date, API access, model ID, pricing, or specifications as confirmed.

Read guide

Claude Opus 5 vs Claude Opus 4.8

Which Opus route to run in production, and what has to improve for Opus 5 to be worth the smaller discount.

Read guide

Claude Opus 5 vs Claude Fable 5

When Opus 5 should be the premium default and when Fable 5 can justify twice the official token price.

Read guide

Claude Opus 5 vs GPT-5.6

How the two frontier routes compare on pricing dimensions, context, and agent workloads.

Read guide

GPT-6 Astra vs Claude Opus 5

Compare published context, cost, and agent controls, then choose a qualified primary route and fallback.

Read guide

Claude Opus 5 API Guide

Make your first request, configure thinking and effort, migrate safely, and use the production checklist.

Read guide

Claude Opus 5 API FAQ

Is the Claude Opus 5 API available through EvoLink?

Yes. Claude Opus 5 is available on EvoLink as a production route under model ID "claude-opus-5".

What model ID should I use for the Claude Opus 5 API?

Send model "claude-opus-5". The same ID works for both the OpenAI-compatible Chat Completions endpoint and the Anthropic Messages endpoint.

How much does the Claude Opus 5 API cost on EvoLink?

EvoLink pricing: $4.750 per 1M input tokens and $23.750 per 1M output tokens, against Anthropic’s $5.000 and $25.000.

How is Claude Opus 5 prompt caching billed?

Cache write and cache read are separate dimensions: $5.939 per 1M cache write tokens and $0.475 per 1M cache read tokens on EvoLink, versus $6.250 and $0.500 official.

How is the Claude Opus 5 web search tool billed?

Web search is charged per search at $0.010. Tokens the search results add to the request are billed normally.

Which protocols and SDKs work with Claude Opus 5?

Use the OpenAI-compatible Chat Completions endpoint or the Anthropic Messages endpoint with the same EvoLink API key. Claude Code and other Anthropic-native clients work by pointing the base URL at EvoLink.

What context window and max output does Claude Opus 5 support?

The EvoLink route records a 1,000,000-token context window with up to 128K output tokens per response.

Is thinking enabled by default on Claude Opus 5?

Anthropic enables adaptive thinking by default on Opus 5, and the Claude API defaults effort to high. Confirm that the specific parameters you need pass through your selected EvoLink endpoint by checking the API docs and an actual response.

What workloads are a good fit for Claude Opus 5?

Claude Opus 5 fits especially demanding coding, long-running agents with heavy tool use, and critical reviews where errors create high downstream costs.

Can I use Claude Opus 5 alongside other model routes?

Yes. With the same EvoLink client and API key, route difficult tasks to Claude Opus 5 and keep tested alternatives for simpler or latency-sensitive requests.

What should a production Claude Opus 5 evaluation measure?

Track first-pass success, accepted deliverables, retries, output tokens, cache hit rate, valid tool calls, time to accepted result, human correction, and fallback rate — not the per-token rate alone.