Claude API Cheatsheet 2026 — Models, Pricing, Limits in One Place

All information verified from Anthropic's official documentation as of May 2026.

Updated May 29, 2026: Claude Opus 4.8 released. Model ID, pricing, and tips updated.

Models

💡 Opus 4.8 and Sonnet 4.6 both support 1M token context at flat rate — no surcharge.

API Pricing (per million tokens)

⚠️ Batch API = 50% discount, but processes within 24 hours (async only).

💡 Fast mode runs at 2.5× speed. Now 3× cheaper than fast mode was for previous Opus models.

¹ fast mode note: Opus 4.8 fast mode ($10/$50) is separately priced from the older Opus 4.6/4.7 fast mode ($30/$150). The fast mode docs now confirm speed: "fast" works with Opus 4.8, but explicit 4.8 pricing is not yet listed there. Prices above are from the official release announcement and Anthropic's pricing page.

Prompt Caching

💡 Best for: system prompts, repeated context, long documents.

💡 Opus 4.8 lowers the minimum cacheable tokens from 4,096 to 1,024 — making caching practical for shorter system prompts too.

Subscription Plans (not API)

⚠️ Subscriptions ≠ API access. API is always billed separately per token.

Basic API Call

import anthropic

client = anthropic.Anthropic(api_key="your_key")

message = client.messages.create(
    model="claude-opus-4-8",
    max_tokens=1024,
    messages=[
        {"role": "user", "content": "Hello!"}
    ]
)
print(message.content[0].text)

Batch API

import anthropic

client = anthropic.Anthropic()

batch = client.messages.batches.create(
    requests=[
        {
            "custom_id": "request-1",
            "params": {
                "model": "claude-sonnet-4-6",
                "max_tokens": 1024,
                "messages": [{"role": "user", "content": "Hello!"}]
            }
        }
    ]
)
print(batch.id)

Mid-task System Updates (NEW in Opus 4.8)

The Messages API now accepts system entries inside the messages array.
This lets you update Claude's instructions mid-task without breaking the prompt cache.

messages=[
    {"role": "user", "content": "Start the migration."},
    {"role": "assistant", "content": "Starting now..."},
    {"role": "system", "content": "Updated instruction: also update test files."},
    {"role": "user", "content": "Continue."},
]

💡 Useful for updating permissions, token budgets, or environment context while an agent is running.

Key Tips

• Haiku → simple classification, summaries, high-volume tasks
• Sonnet → most production use cases, best price/performance
• Opus → complex reasoning, long-horizon agentic tasks (~1.7x more expensive than Sonnet, 5x more than Haiku)
• Use Batch API for non-realtime workloads (50% cheaper)
• Use prompt caching for repeated system prompts (up to 90% cheaper)
• Opus 4.8 defaults to high effort. Use xhigh (Claude Code) or max for harder tasks — more tokens, better results. Rate limits in Claude Code have been increased to accommodate this.
• Opus 4.8 fast mode runs at 2.5× speed at $10/$50 per million tokens — 3× cheaper than fast mode was on previous Opus models.
• Opus 4.8 is ~4× less likely than Opus 4.7 to let code flaws pass unremarked (per Anthropic's evaluations).
• Migrating from Opus 4.7? No new breaking changes have been officially announced for 4.8. Constraints introduced in 4.7 (non-default temperature/top_p/top_k returning 400, adaptive thinking replacing extended thinking) are expected to carry over. Tokenizer is assumed unchanged, but actual token cost may vary — verify with your own inputs.
• Extended thinking: not supported on Opus 4.8 (confirmed in Anthropic's model overview). Use adaptive thinking instead.

Sources: Anthropic news — Introducing Claude Opus 4.8 · Claude API docs

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