# Claude Opus 5.5 — API pricing & integration guide | Y-API

> Claude Opus 5.5 is the successor entry to Opus 5 in Anthropic’s flagship line, listed with a 1,000,000-token window and text, image and file input. The reference positions it at multi-step changes in large codebases and long-horizon agent work.

This is the markdown representation of https://y-api.bestvirtualgoods.com/models/anthropic/claude-opus-5.5. Generated by `scripts/generate-seo-assets.mjs` from the same copy the page renders — do not edit by hand.

Model ID: `anthropic/claude-opus-5.5`

Sources reviewed: 2026-10-21. Y-API catalog snapshot: 2026-10-21.

## Choosing this model

Selection advice by Y-API. The checks below are suggested evaluations, not published test results.

### Where to start

Use it where a change spans several files and the failure mode is a plausible-looking edit that breaks a distant caller. Give it the full diff plus the call sites, and ask it to name what it checked.

### What to watch for

This entry lists only the `openai` endpoint upstream, so an Anthropic-native client pointed at `/v1/messages` is not the path the catalog advertises here. Successor positioning is also not a measured improvement over Opus 5 — treat it as a hypothesis to test.

## Model specifications

These are OpenRouter model-level specifications, not a Y-API compatibility test. A particular route may accept fewer input formats, parameters or tokens. Verify the features you need with a small request; a successful text response does not validate vision or tool calling.

| Field | Value |
| --- | --- |
| Context window | 1,000,000 tokens |
| Input | Text, Image, File |
| Output | Text |
| Listed on OpenRouter | 2026-09-22 |
| Parameters listed by OpenRouter | `include_reasoning`, `max_completion_tokens`, `max_tokens`, `reasoning`, `reasoning_effort`, `response_format`, `stop`, `structured_outputs`, `tool_choice`, `tools`, `verbosity` |

## API pricing & cost estimate

| Price basis | Input / 1M tokens | Output / 1M tokens |
| --- | --- | --- |
| Account credit | $4.00 | $20.00 |
| Cash equivalent | $0.40 | $2.00 |

$1 paid adds $10 of credit. Cash equivalent = credit consumed ÷ 10; this is not the model publisher’s list price.

Input tokens / request: 1000. Output tokens / request: 500. Number of requests: 1000.

Estimated credit consumed: $14.00. Estimated cash equivalent: $1.40.

Illustrative token budget, not measured usage or a quote. Includes input and output; excludes separate media charges, cache discounts and retries. Include billed reasoning tokens in your output budget where applicable. Actual billing follows usage returned by the service.

### Same token budget, different models

| Model | Estimated credit consumed | Estimated cash equivalent |
| --- | --- | --- |
| [Claude Opus 5.5](https://y-api.bestvirtualgoods.com/models/anthropic/claude-opus-5.5) | $14.00 | $1.40 |
| [Claude Opus 5](https://y-api.bestvirtualgoods.com/models/anthropic/claude-opus-5) | $17.50 | $1.75 |
| [Claude Sonnet 5](https://y-api.bestvirtualgoods.com/models/anthropic/claude-sonnet-5) | $7.00 | $0.70 |

[View LLM API pricing & billing](https://y-api.bestvirtualgoods.com/pricing)

## API integration examples

These minimal, text-only requests use the exact Y-API model ID. They do not demonstrate image, audio, video, file or tool support. The output limit also needs room for reasoning; an empty answer with finish_reason=length can mean the budget was exhausted.

Set the TOKEN environment variable to a key from your console. Run this on your server or locally; never expose a key in browser code or a public repository.

### A task to try

This refactor moves a retry helper into a shared module. List every caller that still imports the old path, then show the import change and the test that proves nothing else broke.

```bash
curl --fail-with-body --silent --show-error --max-time 120 \
  'https://api.y-api.bestvirtualgoods.com/v1/chat/completions' \
  -H "Authorization: Bearer ${TOKEN:?Set TOKEN first}" \
  -H 'Content-Type: application/json' \
  --data-binary @- <<'JSON'
{
  "model": "anthropic/claude-opus-5.5",
  "messages": [
    {
      "role": "user",
      "content": "This refactor moves a retry helper into a shared module. List every caller that still imports the old path, then show the import change and the test that proves nothing else broke."
    }
  ],
  "max_tokens": 4096
}
JSON
```

```python
import json
import os
import sys
import urllib.error
import urllib.request

payload = {
  "model": "anthropic/claude-opus-5.5",
  "messages": [
    {
      "role": "user",
      "content": "This refactor moves a retry helper into a shared module. List every caller that still imports the old path, then show the import change and the test that proves nothing else broke."
    }
  ],
  "max_tokens": 4096
}

request = urllib.request.Request(
    "https://api.y-api.bestvirtualgoods.com/v1/chat/completions",
    data=json.dumps(payload).encode("utf-8"),
    headers={
        "Authorization": "Bearer " + os.environ["TOKEN"],
        "Content-Type": "application/json",
    },
    method="POST",
)
try:
    with urllib.request.urlopen(request, timeout=120) as response:
        result = json.load(response)
    print(json.dumps(result, ensure_ascii=False, indent=2))
except urllib.error.HTTPError as error:
    print(error.read().decode("utf-8"), file=sys.stderr)
    raise SystemExit(1)
```

### How to evaluate the result

The answer should be reproducible: a search that finds the stale imports, a diff, and a test run. An edit that only compiles, with no call-site inventory, is the failure this check is designed to catch.

## Before you choose

### Is Opus 5.5 cheaper than Opus 5 on this catalog?

Check the price table on this page rather than assuming. The two are separate catalog entries with their own rates, and the newer version number does not by itself tell you which one costs less per token.

## Sources & scope

Technical facts come from the cited model page and, where available, its linked publisher card. A card describes that checkpoint; it is not proof of the weights a gateway serves. Prices come only from the Y-API catalog. We do not claim measured latency, uptime or benchmark scores for this endpoint.

- [OpenRouter model page & specifications](https://openrouter.ai/anthropic/claude-opus-5.5)
- [Y-API catalog & prices (JSON)](https://y-api.bestvirtualgoods.com/models.json)

## Models to compare

Compare these alternatives on the same inputs. Their descriptions explain different roles; a lower price does not establish equivalent quality.

### [Claude Opus 5](https://y-api.bestvirtualgoods.com/models/anthropic/claude-opus-5)

Claude Opus 5 is positioned by OpenRouter as Anthropic’s model for demanding reasoning, software engineering and extended agent work. The reference entry lists text, image and file input with text output.

### [Claude Sonnet 5](https://y-api.bestvirtualgoods.com/models/anthropic/claude-sonnet-5)

Claude Sonnet 5 is Anthropic’s Sonnet-class model for coding and professional work. The reviewed reference describes adaptive thinking and an updated tokenizer, so migration involves more than changing a display name.

## Links

- HTML version of this page: https://y-api.bestvirtualgoods.com/models/anthropic/claude-opus-5.5
- Site index for agents: https://y-api.bestvirtualgoods.com/llms.txt
- Full reference (single file): https://y-api.bestvirtualgoods.com/llms-full.txt
- OpenAPI 3.1 spec: https://y-api.bestvirtualgoods.com/openapi.json
- Model catalog (JSON, no key needed): https://y-api.bestvirtualgoods.com/models.json
- API base URL: `https://api.y-api.bestvirtualgoods.com/v1`
- Contact: support@bestvirtualgoods.com
- Model catalog: https://y-api.bestvirtualgoods.com/models
- Integration guide: https://y-api.bestvirtualgoods.com/docs