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How I Combine Opus 4.7 and Sonnet 4.6 in Claude Code

My practical workflow: use Opus 4.7 for critical planning and Sonnet 4.6 for cost-efficient execution loops.

Matthews Wong

Software Engineer

April 20267 min read
How I Combine Opus 4.7 and Sonnet 4.6 in Claude Code

Image source: Anthropic - Introducing Claude Opus 4.7

Claude Opus 4.7 launched on April 16, 2026 as Anthropic's newest generally available flagship for complex reasoning and coding. If you work with agents, code generation, or multimodal workflows, this release is worth paying attention to.

What is new in Opus 4.7

  • Stronger coding and agentic execution, especially on long multi-step tasks that previously needed closer supervision.
  • Better instruction following, which improves reliability but also means old prompts may need retuning.
  • Higher-fidelity vision support with images up to 2,576 pixels on the long edge, useful for dense screenshots and technical diagrams.
  • New effort level xhigh between high and max for finer reasoning-versus-latency control.
  • Task budgets in public beta on Claude Platform to guide token spend on longer autonomous runs.
  • Same API pricing as Opus 4.6: $5 per million input tokens and $25 per million output tokens, with availability across Claude API, Bedrock, Vertex AI, and Microsoft Foundry.

Behavior changes to know (sourced)

Anthropic's official launch and best-practices notes describe several default behavior changes in Opus 4.7 compared with earlier Opus versions.

  • Instruction following is more literal, so prompts tuned for older models can behave differently and should be re-tested.
  • Response length is more calibrated to task complexity, with shorter output on simple requests and longer output for open-ended analysis.
  • The model tends to call tools less often by default and may reason more before acting, unless tool-use guidance is explicit.
  • The model is more selective about spawning subagents unless delegation and parallel fan-out are clearly requested.

Session structure tactics from Anthropic

In Anthropic's Opus 4.7 Claude Code best-practices post, these tactics are emphasized for better quality and token efficiency in interactive sessions.

Define the full task in turn one

Include intent, constraints, acceptance criteria, and relevant file locations up front instead of revealing context gradually.

Reduce back-and-forth turns

Batch questions and required context in fewer user turns because each additional turn can add reasoning overhead.

Use auto mode when trust is established

For long-running tasks where guardrails are clear, auto mode can reduce cycle time by minimizing interruptions.

Set completion notifications

Use hook-based completion notifications so long tasks can finish asynchronously without constant manual checking.

Adaptive thinking controls (prompt-level)

Opus 4.7 uses adaptive thinking. Anthropic suggests nudging the model through prompt wording when you want more depth or more speed.

  • For deeper reasoning: Ask it to think carefully and step-by-step before responding on harder problems.
  • For speed: Ask it to prioritize a direct response and avoid deep thinking unless necessary.

Effort level decision matrix

The matrix below summarizes Anthropic guidance for choosing effort levels in Claude Code workflows.

Effort levelWhen to useTradeoff
lowTightly scoped or latency-sensitive tasks.Lowest cost and fastest responses, but reduced depth on harder tasks.
mediumCost-sensitive coding and straightforward implementation loops.Good throughput with moderate reasoning depth.
highBalanced coding work or multiple concurrent sessions.Better quality than medium with more token spend.
xhigh (default)Most agentic coding, design decisions, and complex refactors.Best practical balance of intelligence and cost for most serious tasks.
maxHardest intelligence-sensitive tasks and targeted evaluation runs.Highest quality ceiling with diminishing returns and highest token usage.

Token impact scenarios

Anthropic flags three migration-sensitive token factors: tokenizer updates, higher-effort reasoning, and high-resolution vision inputs.

ScenarioToken impactPractical action
Migration of existing prompts from Opus 4.6Equivalent text can map to roughly 1.0x to 1.35x tokens depending on content.Benchmark real traffic before full rollout and adjust budget thresholds.
Long coding sessions at high/xhigh/max effortLater turns can produce more output tokens due to deeper reasoning.Use high or xhigh first, then reserve max for only the hardest steps.
Vision workflows with dense screenshots and diagramsHigher-resolution image understanding increases token usage when fine detail is processed.Downsample images when fine-grained detail is not required.

Migration notes before upgrading

  • Expect token usage shifts: Opus 4.7 uses an updated tokenizer and equivalent text can map to roughly 1.0x to 1.35x tokens depending on content.
  • At higher effort levels, the model can emit more output tokens, so set effort intentionally for your workload.
  • Anthropic flags API breaking changes versus Opus 4.6, so review the migration guide and test on real traffic before full rollout.

My experience using Opus 4.7 in Claude Code

After testing Opus 4.7 in Claude Code, I found it excellent for critical thinking and planning mode. It structures hard problems clearly, catches assumptions, and produces stronger implementation plans than most models.

The tradeoff is token speed. Opus 4.7 can consume tokens quickly during long sessions, especially when effort is high and the task spans multiple tool calls.

  • Use Opus 4.7 for planning mode: architecture decisions, task breakdowns, debugging strategy, and risk analysis.
  • Switch to Sonnet 4.6 for execution mode: finishing tasks, iterative edits, and lower-cost completion loops.

Where Opus 4.7 shines the most

  • Critical planning for complex refactors across multiple services.
  • Design reviews where tradeoffs, risks, and edge cases matter.
  • Root-cause analysis for bugs that require long context and hypothesis testing.
  • Agent orchestration prompts where quality of planning directly affects execution.

Practical model playbook I use

  • Start in Opus 4.7 with planning prompts: ask for architecture, milestones, risks, and rollback paths.
  • Lock the plan into a checklist before writing code.
  • Switch to Sonnet 4.6 for implementation loops: code edits, test fixes, and task completion.
  • Return to Opus 4.7 only for blockers that need deep reasoning.
  • Keep prompts concise in both models to reduce unnecessary token burn.

Quick checklist before you start

  • Decide first: planning session or execution session.
  • Set effort intentionally; avoid max unless the task truly requires it.
  • Track token usage every few turns during long runs.
  • Use Sonnet 4.6 as default finisher for stable throughput.

Teams are moving fast on Opus 4.7 because it pairs stronger quality with practical controls for cost and reliability. This is the right time to benchmark it in your own stack.

FAQ

Frequently Asked Questions

Short answers to what readers ask most about this topic.

What is the recommended workflow for combining Opus 4.7 and Sonnet 4.6 in Claude Code?

Use Opus 4.7 for planning mode — architecture decisions, task breakdowns, debugging strategy, and risk analysis — then switch to Sonnet 4.6 for execution mode, which covers iterative edits, test fixes, and lower-cost completion loops. Return to Opus 4.7 only when a blocker requires deep reasoning. This two-model approach balances Opus 4.7's stronger planning quality against Sonnet 4.6's cost efficiency and throughput.

What is the new 'xhigh' effort level in Opus 4.7 and when should it be used?

The xhigh effort level sits between high and max, and Anthropic recommends it as the default for most agentic coding work, design decisions, and complex refactors. It provides the best practical balance of intelligence and cost for serious tasks, without the diminishing returns and highest token usage that come with max. Reserve max only for the hardest intelligence-sensitive tasks and targeted evaluation runs.

How does Opus 4.7's instruction following differ from earlier Opus models, and why does this matter for migration?

Opus 4.7's instruction following is more literal than earlier Opus versions, which means prompts tuned for older models can behave differently and should be re-tested before full rollout. Additionally, the updated tokenizer means equivalent text can map to roughly 1.0x to 1.35x more tokens depending on content. Anthropic also flags API breaking changes versus Opus 4.6, so reviewing the migration guide and testing on real traffic is recommended before switching fully.

What session tactics does Anthropic recommend to improve quality and token efficiency in Claude Code with Opus 4.7?

Anthropic recommends defining the full task — including intent, constraints, acceptance criteria, and relevant file locations — in the very first turn rather than revealing context gradually. Batching questions into fewer user turns reduces reasoning overhead, and using auto mode for long tasks with clear guardrails minimizes interruptions. Hook-based completion notifications allow long tasks to finish asynchronously without constant manual checking.

How should vision workflows be handled to manage token costs when using Opus 4.7?

Opus 4.7 supports higher-fidelity vision with images up to 2,576 pixels on the long edge, which is useful for dense screenshots and technical diagrams. However, higher-resolution image understanding increases token usage when fine detail is processed, so Anthropic recommends downsampling images when fine-grained detail is not actually required. This is one of three migration-sensitive token factors flagged alongside tokenizer updates and higher-effort reasoning.