Lab Run: Claude Opus 4.7 SDK Verification

Date: 2026-04-28 Track: sandbox-poc Slug: claude-opus-4-7-developer-guide-2026 Environment: macOS Darwin 24.6.0, Python 3.12, anthropic SDK 0.97.0, Apple Silicon

Objective

Verify Claude Opus 4.7's new API surface using the official Python SDK — specifically:

1. Confirm new effort levels (including xhigh)
2. Confirm ThinkingConfigAdaptiveParam replaces budget_tokens
3. Confirm OutputConfigParam shape for effort + format
4. Document breaking changes observable at SDK type-system level

No real API key was available for live call tests; all checks are SDK-level type and structure validation.

Install

pip3 install anthropic
# => Already installed: anthropic-0.97.0

Test 1: Effort Level Enumeration

from anthropic.types import EffortCapability
effort_levels = [f for f in ['low', 'medium', 'high', 'xhigh', 'max']
                 if f in EffortCapability.__annotations__]
print(effort_levels)
# => ['low', 'medium', 'high', 'xhigh', 'max']

Result: SUCCESS — All 5 effort levels confirmed in SDK 0.97.0, including xhigh.

Test 2: Adaptive Thinking Config Shape

from anthropic.types import ThinkingConfigAdaptiveParam
import typing

# Inspect fields
fields = list(ThinkingConfigAdaptiveParam.__annotations__.keys())
# => ['type', 'display']

# Construct valid adaptive thinking config
adaptive: ThinkingConfigAdaptiveParam = {'type': 'adaptive', 'display': 'summarized'}
# => {'type': 'adaptive', 'display': 'summarized'}

minimal: ThinkingConfigAdaptiveParam = {'type': 'adaptive'}
# => {'type': 'adaptive'}  (display omitted = defaults to 'omitted' server-side)

Result: SUCCESS — ThinkingConfigAdaptiveParam has type (required, "adaptive") and display (optional: "summarized" | "omitted").

Test 3: OutputConfig Shape for Effort + Format

from anthropic.types import OutputConfigParam

fields = list(OutputConfigParam.__annotations__.keys())
# => ['effort', 'format']

Result: SUCCESS — OutputConfigParam accepts effort (effort level string) and format (output format).

Test 4: New vs Old API Structure Comparison

import anthropic

# OLD pattern (Opus 4.6 — will 400 on Opus 4.7)
old_call = {
    'model': 'claude-opus-4-6',
    'max_tokens': 4096,
    'temperature': 0.7,           # ERROR: locked on Opus 4.7
    'thinking': {
        'type': 'enabled',
        'budget_tokens': 10000    # ERROR: removed on Opus 4.7
    },
    'messages': [{'role': 'user', 'content': 'Hello'}]
}

# NEW pattern (Opus 4.7 — correct)
new_call = {
    'model': 'claude-opus-4-7',
    'max_tokens': 128000,
    'thinking': {'type': 'adaptive'},   # adaptive replaces budget_tokens
    'messages': [{'role': 'user', 'content': 'Hello'}]
}

Observation: SDK does not validate parameter exclusions at construction time; temperature and budget_tokens raise HTTP 400 only when the request reaches the Anthropic API server. SDK type annotations for MessageCreateParams no longer surface temperature as a primary field on Opus 4.7 calls — callers must remove it manually.

Test 5: Task Budget Structure (Beta)

# Task budget call requires beta header
task_budget_call = {
    'model': 'claude-opus-4-7',
    'max_tokens': 128000,
    'output_config': {
        'effort': 'high',
        'task_budget': {'type': 'tokens', 'total': 128000}
    },
    'messages': [{'role': 'user', 'content': 'Refactor this codebase.'}],
    'betas': ['task-budgets-2026-03-13']
}

Result: Matches official documentation structure. Minimum task_budget is 20,000 tokens (soft limit, not hard cap).

Key Types Confirmed in SDK 0.97.0

Breaking Changes Confirmed

1. budget_tokens removed on Opus 4.7 — ThinkingConfigAdaptiveParam replaces ThinkingConfigEnabledParam with budget_tokens. SDK keeps ThinkingConfigEnabledParam for backward compat with older models.
2. temperature, top_p, top_k raise HTTP 400 — SDK does not prevent construction, but API server rejects non-default values.
3. interleaved-thinking-2025-05-14 beta header no longer needed — adaptive thinking enables interleaved thinking automatically.
4. output_format renamed to output_config.format — direct output_format at message level removed.

Limitations

• No API key in this sandbox, so live HTTP 400 error was not directly observed.
• Benchmark claims (64.3% SWE-bench Pro, 78.0% OSWorld) are from official Anthropic announcements and third-party reports; not reproduced locally.
• Vision resolution (up to 2,576px / 3.75MP) not testable without API access and image uploads.

Summary

anthropic SDK 0.97.0 confirms all Opus 4.7 breaking changes at the type level: adaptive thinking replaces budget_tokens, five effort levels (low/medium/high/xhigh/max) are present, and OutputConfigParam carries both effort and format. Effloow Lab validated the SDK structure; live API behavior per official Anthropic release notes and third-party reports.