# Claude Code v2.0.51

> Claude Code v2.0.51, released 24 Nov 2025 (2025-11-24). 11 entries read out of the shipped bundle. Unofficial, and not affiliated with Anthropic.

Web version: https://changelogs.core-directive.com/v/2.0.51

This release introduces **Opus 4.5 model support** for first-party API users, adds the new **EnterPlanMode tool** enabling Claude to proactively request plan mode, and significantly improves **rate limit warnings** with utilization percentages and smart thresholds. Multiple UX enhancements including grouped agent display and trailing thinking block filtering improve the overall experience.

## Changes

### Opus 4.5 Model Support

**What:** Opus 4.5 is now available as the most capable model for complex work, replacing Opus 4.1 as the default for first-party API users.

**How to use:**

`# Select Opus 4.5 via the model command /model opus # Or specify directly claude --model opus` **Details:**

- Opus 4.5 becomes the default for Max and Team subscribers using first-party API
- Bedrock/Vertex/Foundry users continue to use Opus 4.1
- Model descriptions updated: "Most capable for complex work"
- One-time migration automatically resets model selection for eligible users
- A notification informs users about Opus 4.5 availability on first use
- **Evidence**: Model registry at `rcA()` line 163104, default logic at `QUA()` line 224121, selector at `rJ6` line 224397

### EnterPlanMode Tool

**What:** A new tool that allows Claude to proactively request permission to enter plan mode for complex tasks requiring careful exploration before implementation.

**How to use:**

`# Claude will automatically suggest entering plan mode for complex tasks # You'll see a prompt: "Enter plan mode?" # Press 'y' to approve or 'n' to decline` **Details:**

- Requires user approval before entering plan mode
- Designed for tasks with multiple valid approaches, architectural decisions, or unclear requirements
- Includes extensive documentation on when to use vs. not use plan mode
- Cannot be used from agent contexts (main conversation only)
- **Evidence**: Tool definition at `GRA` variable in `_50` at line 425698, prompt at `vb2` line 425575

### Rate Limit Utilization Warnings

**What:** Rate limit warnings now show exact utilization percentages and use intelligent thresholds based on both token usage and time remaining.

**How it appears:**

`75% of 5-hour limit used · resets in 2h 50% of weekly limit used · resets in 3d` **Details:**

- Shows percentage of limit used instead of generic "Approaching limit" messages
- Smart thresholds: warns at 75%/60%, 50%/35%, 25%/15% (tokens/time) for weekly limits
- 5-hour limits now show warnings (previously silent)
- Considers usage rate vs. time remaining in window
- **Evidence**: Function `N49()` at line 467497, threshold config at `j$3`/`S$3` line 467531

### Grouped Agent Display

**What:** When multiple Task agents run simultaneously, the UI now shows a collapsed summary view that can be expanded with ctrl+o.

**How it appears:**

`Running 3 agents… (ctrl+o to expand) ├─ investigator (Check auth flow) · 5 tool uses · 2.3k tokens ├─ investigator (Find routes) · 3 tool uses · 1.8k tokens └─ investigator (Review tests) · 7 tool uses · 3.1k tokens` **Details:**

- Reduces visual clutter when multiple agents run in parallel
- Shows agent type, description, tool use count, and token usage
- Displays "X agents finished" when complete
- Same-type agents show grouped label (e.g., "Running 3 investigator agents…")
- **Evidence**: Main renderer `i49()` at line 469450, item renderer `g49()` at line 469102

### Extra Usage Integration Enhanced

The extra usage feature now has deeper integration with account state and re-authentication flows.

- Added `hasExtraUsageEnabled` account property tracked via OAuth
- `/extra-usage` command now triggers re-authentication to sync state
- Pro users with extra usage enabled get access to Opus features
- **Evidence**: Account property at `DC1()` line 67554, API mapping at line 67521

### Improved Rate Limit Error Messages

Rate limit error messages now provide actionable guidance specific to your subscription tier.

- Messages suggest specific actions: `/upgrade to Max`, `turn on /extra-usage`, `/model opus`
- Different guidance for Pro, Max, Team, and Enterprise users
- Sonnet weekly limit now has distinct messaging from general weekly limit
- **Evidence**: Function `YLA()` at line 336478

### Model Description Updates

- Sonnet 4.5: "Best for everyday tasks" (was "Smartest model for daily use")
- Opus: "Most capable for complex work"
- Haiku 4.5: "Fastest for quick answers" (was "Fastest model for simple tasks")
- Dynamic pricing display using `jc()` helper function
- **Evidence**: Model options at `qh1`, `kzB`, `xzB` around line 224380

### November 2025 Limits Update Notice

Max and Team users see an informational notice about limit changes:

- Opus cap removed - can use Opus 4.5 up to overall limit
- Sonnet now has its own separate limit
- **Evidence**: Function `TN3()` at line 477797

### Trailing Thinking Block Filtering

Assistant messages ending with thinking blocks now have those blocks automatically filtered out before display.

- Prevents display of incomplete or dangling thinking blocks
- Logs telemetry about filtered blocks for debugging
- Replaces content with "[No message content]" if all blocks were thinking
- **Evidence**: Function `GT3()` at line 504394, helper `oX9()` at line 504391

### Default Model Logic for Max/Team Users

Max and Team subscribers now default to Opus 4.5 instead of requiring manual model selection.

- First-party API users get Opus 4.5 by default
- Cloud provider (Bedrock/Vertex) users continue with Opus 4.1
- Respects `ANTHROPIC_DEFAULT_OPUS_MODEL` environment variable override
- **Evidence**: Function `PnA()` at line 224154, `QUA()` at line 224121

### Model Detection Extended

The model detection functions now correctly recognize Opus 4.5 model IDs.

- `claude-opus-4-5` pattern now properly identified
- Fixes potential issues with model-specific features not activating for Opus 4.5
- **Evidence**: Detection at `KAB()` line 163004, `Pw()` line 224165