Sync Claude Code upstream da80366 → 420a188: add --effort and --name flags

[Copilot]

Advances the anthropics/claude-code submodule pin from da80366 to 420a188 and surfaces two CLI flags added in that range into the SDK.

New flags

• --effort <level> (CLI v2.1.72): controls model effort for a session
  • New EffortLevel enum: Low | Medium | High | Max
  • ToCliValue() extension maps enum → low | medium | high | max
• --name <name> / -n (CLI v2.1.76): sets a display name for the session

Propagation path (both flags)

ThreadOptions → ClaudeExecArgs → ClaudeExec.BuildCommandArgs → CLI

Usage

var thread = client.CreateThread(new ThreadOptions
{
    Effort = EffortLevel.High,
    Name = "refactor-session",
});

Files changed

File	Change
Client/ThreadOptions.cs	EffortLevel enum + Effort/Name properties
Execution/ClaudeExecArgs.cs	Effort/Name properties
Execution/ClaudeExec.cs	--effort / --name flag constants + build logic
Internal/ClaudeCliValueExtensions.cs	ToCliValue(EffortLevel) with EffortLevelValues constants
Client/ClaudeThread.cs	maps new ThreadOptions fields into ClaudeExecArgs
Tests/Unit/ClaudeExecTests.cs	8 new tests covering all effort levels and name flag
submodules/anthropic-claude-code	pinned to 420a188

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Sync Claude Code upstream changes (da80366 -> 420a188)</issue_title>
<issue_description>

Detected upstream updates in anthropics/claude-code affecting Claude Code CLI surface tracking.

Runtime source of truth for this SDK is the real print-mode CLI contract:

• claude -p --output-format json

• claude -p --output-format stream-json --verbose

• Submodule path: submodules/anthropic-claude-code

• Published CLI package used in CI: @anthropic-ai/claude-code

• Watched branch: main

• Current pinned commit: da80366c484698e6370ad9e8abf121f33f8f79e0

• Latest upstream commit: 420a1884671fe09addc881f9a62624dae952d21c

• Compare: anthropics/claude-code@da80366...420a188

• Latest commit: anthropics/claude-code@420a188

Changed files (CLI-relevant)

• CHANGELOG.md

Potential CLI flag changes from diff

• --agents
• --compact
• --continue
• --effort
• --git
• --model
• --name
• --plugin-dir
• --print
• --resume
• --verbose
• --worktree

Potential model changes from diff

• claude-code
• claude-opus-4-5

Potential feature changes from diff

• (no feature tokens detected from diff)

Commits

• 420a188 chore: Update CHANGELOG.md (2026-03-14)
• 48b1c6c chore: Update CHANGELOG.md (2026-03-13)
• db8834b feat(code-review): pass confirmed=true when posting inline comments (2026-03-11)
• 6f049b6 chore: Update CHANGELOG.md (2026-03-12)
• 45b5430 chore: Update CHANGELOG.md (2026-03-11)
• f6dbf44 chore: Update CHANGELOG.md (2026-03-10)
• 540b61b chore: Update CHANGELOG.md (2026-03-10)
• 00553de chore: Update CHANGELOG.md (2026-03-10)
• 53a5f3e chore: Update CHANGELOG.md (2026-03-07)

Action required

• Pull the new anthropics/claude-code submodule commit into this repository
• Validate latest claude --help output and representative non-interactive runtime behavior
• Re-check claude -p --output-format json and claude -p --output-format stream-json --verbose payload shape
• Sync C# SDK constants/options/models with upstream CLI changes
• Add or update tests for new flags/models/features
• Update docs (README + docs/Features + docs/Architecture if needed)

Opened automatically by scheduled workflow 'Claude Code Upstream Watch'.</issue_description>

<agent_instructions>Check and update code if needed but create just one. Branch and on pr </agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes Sync Claude Code upstream changes (da80366 -> 420a188) #6

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