Claude Opus 5.5 API
First of the Claude 5.5 generation: Fable-class agentic coding and computer use at 20% below Opus 5.
Model spec
- Input
- $4.00per 1M tokens
- Output
- $20.00per 1M tokens
- Cached input
- $0.20per 1M tokens
- Context
- 1M
- Max output
- 128K
Model ID
OpenAI-compatible · api.companyfabric.com/v1
Overview
About Claude Opus 5.5
First of the Claude 5.5 generation: Fable-class agentic coding and computer use at 20% below Opus 5. Every model on CompanyFabric shares the same API key, billing balance, and rate-limit envelope, one integration covers the entire library.
Facts
At a glance
Availability
Live
Added 22 Sep 2026
Pricing
$4.00 in · $20.00 out
Per 1M tokens, metered exactly per call
Context window
1M tokens
Up to 128K tokens out
Commercial use
See license
Commercial use of outputs permitted per Anthropic's usage policies.
Variants
All endpoints
Claude Sonnet 4.5
Retiring$3/Mtok inFrontier-quality text and reasoning through one OpenAI-compatible endpoint.
Chat Completions
Claude Haiku 4.5
$1/Mtok inFast, cheap frontier-family model for high-volume tasks.
Chat Completions
Claude Opus 4.6
$5/Mtok inThe frontier tier for the hardest reasoning and agentic work.
Chat Completions
Claude Fable 5
$10/Mtok inAnthropic's first Mythos-class model, the new flagship tier above Opus, tuned for the hardest reasoning and agentic work.
Chat Completions
Claude Opus 5
$5/Mtok inThe Claude 5 generation's deep-work model, maximum-capability reasoning for research, architecture, and hard agentic tasks.
Chat Completions
Claude Opus 5.5
$4/Mtok inFirst of the Claude 5.5 generation: Fable-class agentic coding and computer use at 20% below Opus 5.
Chat Completions
Claude Sonnet 5.5
$2/Mtok inThe fast Claude 5.5: near-Opus coding and knowledge work, 30%+ faster than Sonnet 5, at half Opus 5.5's price.
Chat Completions
Claude Fable 5.1
$10/Mtok inAnthropic's top generally available model, tied for first on the Artificial Analysis Intelligence Index.
Chat Completions
Claude Haiku 5.5
$0.1/Mtok inAnthropic's cheapest and fastest Claude: a big step up from Haiku 4.5 in coding, computer use and knowledge work, at $0.10 / $0.50 per 1M tokens for prompts up to 100K.
Chat Completions
Quickstart
How to use the Claude Opus 5.5 API
- 1
Create a free CompanyFabric account, starter credits are included, no card required.
- 2
Copy your API key from the dashboard. One key covers every model in the library.
- 3
Point any OpenAI SDK at api.companyfabric.com/v1 and set model to "anthropic/claude-opus-5-5".
- 4
Read the exact metered cost of the call from the response, the same number shown in the playground.
Use cases
What teams build with it
Agents & copilots
Drive agent loops, tool calls, and user-facing assistants over the OpenAI-compatible endpoint.
agentstool useassistants
Content pipelines
Summarization, rewriting, and structured generation at metered per-token cost.
contentsummarization
Extraction & classification
Turn unstructured input into typed JSON with schema-constrained output.
extractionjson mode
Get better output
Prompting tips
- State the output format before the task, models follow contracts declared early.
- Few-shot beats description: two worked examples outperform a paragraph of rules.
- Cap output length explicitly when cost matters; output tokens dominate most bills.
Exact, metered, prepaid
Claude Opus 5.5 pricing
Claude Opus 5.5 pricing is per token: $4 / M input · $20 / M output · $0.2 / M cached input. Output tokens cost 5× input tokens, so long generations, not long prompts, are what actually drive most bills. A typical call with a 2k-token prompt and a 1k-token answer costs about $0.0280.
Every call is metered exactly and attributed to your key, the dashboard, the API usage response, and your invoice all read from the same ledger row. Cap any key's monthly spend with a budget cap, and bring your own provider key (BYOK) at 0% platform fee if you already have a direct contract.
| Endpoint | Type | Price |
|---|---|---|
| Claude Sonnet 4.5 | Chat | $3 / M input · $15 / M output · $0.3 / M cached input |
| Claude Haiku 4.5 | Chat | $1 / M input · $5 / M output · $0.1 / M cached input |
| Claude Opus 4.6 | Chat | $5 / M input · $25 / M output · $0.5 / M cached input |
| Claude Fable 5 | Chat | $10 / M input · $50 / M output · $1 / M cached input |
| Claude Opus 5 | Chat | $5 / M input · $25 / M output · $0.5 / M cached input |
| Claude Opus 5.5 | Chat | $4 / M input · $20 / M output · $0.2 / M cached input |
| Claude Sonnet 5.5 | Chat | $2 / M input · $10 / M output · $0.1 / M cached input |
| Claude Fable 5.1 | Chat | $10 / M input · $50 / M output · $0.25 / M cached input |
| Claude Haiku 5.5 | Chat | $0.1 / M input · $0.5 / M output · $0.01 / M cached input |
Starter credits
Use Claude Opus 5.5 free
Your CompanyFabric starter credits cover your first Claude Opus 5.5 calls at no cost, create a free account, no card required, and the credits apply to Claude Opus 5.5 and every other model on the key. When they run out, prepaid credits or BYOK (0% fee) take over with no plan to pick.
Production-grade
Code samples
import OpenAI from "openai"
const client = new OpenAI({
baseURL: "https://api.companyfabric.com/v1",
apiKey: process.env.COMPANYFABRIC_API_KEY,
})
const res = await client.chat.completions.create({
model: "anthropic/claude-opus-5-5",
max_tokens: 1024,
temperature: 0.7,
messages: [{ role: "user", content: "Say hello from the fabric." }],
})
console.log(res.choices[0].message.content)Playground
Try it in the browser
Comparisons
Claude Opus 5.5 vs the alternatives
Claude Opus 5.5 vs GPT-6 Sol
Claude Opus 5.5 and GPT-6 Sol compete for the same text workloads. Both run behind the same CompanyFabric key at exact metered prices, A/B them on your real prompts and let the outputs decide, then switch with a one-line change.
Full comparison: Claude Opus 5.5 vs GPT-6 Sol →Claude Opus 5.5 vs GPT-6 Astra
Claude Opus 5.5 and GPT-6 Astra compete for the same text workloads. Both run behind the same CompanyFabric key at exact metered prices, A/B them on your real prompts and let the outputs decide, then switch with a one-line change.
Full comparison: Claude Opus 5.5 vs GPT-6 Astra →Claude Opus 5.5 vs Gemini 3.1 Pro (preview)
Claude Opus 5.5 and Gemini 3.1 Pro (preview) compete for the same text workloads. Both run behind the same CompanyFabric key at exact metered prices, A/B them on your real prompts and let the outputs decide, then switch with a one-line change.
Full comparison: Claude Opus 5.5 vs Gemini 3.1 Pro (preview) →Compare
Claude Opus 5.5 head to head
FAQ
Frequently asked questions
How much does the Claude Opus 5.5 API cost?
$4 / M input · $20 / M output · $0.2 / M cached input. Every call is metered exactly and shown before you run it.
How do I get a Claude Opus 5.5 API key?
Create a CompanyFabric account, and one key unlocks Claude Opus 5.5 and every other model in the library. Free starter credits are included, no subscription, no card required to try it.
Why use Claude Opus 5.5 on CompanyFabric instead of going direct?
One key, one prepaid balance, and one rate-limit envelope across the whole library, at pricing at parity with or below the direct API. Model switching is a one-line change, and BYOK routing is 0% fee.
Is the API OpenAI-compatible?
Yes, point any OpenAI SDK at api.companyfabric.com/v1 and set model to "anthropic/claude-opus-5-5".
Can I use the output commercially?
Commercial use of outputs permitted per Anthropic's usage policies.
How does billing work?
Prepaid credits via card, or BYOK with your own provider keys at 0% platform fee. No subscription required; balances never expire.
Provider
About Anthropic
Anthropic publishes the claude family. Also in this family: Claude Sonnet 4.5, Claude Haiku 4.5, Claude Opus 4.6, Claude Fable 5, Claude Opus 5, Claude Sonnet 5.5, Claude Fable 5.1, Claude Haiku 5.5. License: Commercial use of outputs permitted per Anthropic's usage policies.
One key. Every model. Exact prices.
Run Claude Opus 5.5 with free starter credits. Free starter credits included, no subscription required.