# Model Switch History Tracker

Claude Code model switch detector tracking transitions between Opus/Sonnet/Haiku with switch count, current model indicator, and cost impact visualization.

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## Metadata

**Title:** Model Switch History Tracker
**Category:** statuslines
**Author:** JSONbored
**Added:** October 2025
**Tags:** model-switching, opus-sonnet-haiku, cost-optimization, model-tracking, switch-history
**URL:** https://claudepro.directory/statuslines/model-switch-history-tracker

## Overview

Claude Code model switch detector tracking transitions between Opus/Sonnet/Haiku with switch count, current model indicator, and cost impact visualization.

## Content

#!/usr/bin/env bash
MODEL SWITCH HISTORY TRACKER FOR CLAUDE CODE
TRACKS TRANSITIONS BETWEEN CLAUDE MODELS (OPUS, SONNET, HAIKU)
READ JSON FROM STDIN
read -r input
EXTRACT CURRENT MODEL INFO
currentmodel=$(echo "$input" | jq -r '.model.displayname // "unknown"')
sessionid=$(echo "$input" | jq -r '.sessionid // "unknown"')
MODEL HISTORY TRACKING DIRECTORY
HISTORY_DIR="${HOME}/.claude-code-model-history"
mkdir -p "$HISTORY_DIR"
SESSION-SPECIFIC HISTORY FILE
HISTORYFILE="${HISTORYDIR}/${session_id}.history"
INITIALIZE HISTORY FILE IF DOESN'T EXIST
if [ ! -f "$HISTORY_FILE" ]; then
 echo "${currentmodel}" > "$HISTORYFILE"
 echo "0" >> "$HISTORY_FILE" # Switch count
fi
READ PREVIOUS MODEL AND SWITCH COUNT
previousmodel=$(sed -n '1p' "$HISTORYFILE")
switchcount=$(sed -n '2p' "$HISTORYFILE")
DETECT MODEL SWITCH
if [ "$currentmodel" != "$previousmodel" ] && [ "$previous_model" != "" ]; then
 # Model changed - increment switch count
 switchcount=$((switchcount + 1))

 # Log switch event (append to history)
 echo "$(date +%s)|${previousmodel}→${currentmodel}" >> "$HISTORY_FILE"
fi
UPDATE CURRENT MODEL AND SWITCH COUNT (OVERWRITE FIRST 2 LINES)
tempfile="${HISTORYFILE}.tmp"
echo "${currentmodel}" > "$tempfile"
echo "${switchcount}" >> "$tempfile"
tail -n +3 "$HISTORYFILE" >> "$tempfile" 2>/dev/null
mv "$tempfile" "$HISTORYFILE"
DETERMINE MODEL TIER AND COLOR
case "$current_model" in
 "Opus"|"opus")
 MODEL_COLOR="\[38;5;201m" # Magenta: Opus (most expensive)
 MODEL_ICON="💎"
 MODEL_TIER="OPUS"
 ;;
 "Sonnet"|"sonnet")
 MODEL_COLOR="\[38;5;75m" # Blue: Sonnet (balanced)
 MODEL_ICON="🎵"
 MODEL_TIER="SONNET"
 ;;
 "Haiku"|"haiku")
 MODEL_COLOR="\[38;5;46m" # Green: Haiku (cheapest)
 MODEL_ICON="🍃"
 MODEL_TIER="HAIKU"
 ;;
 *)
 MODEL_COLOR="\[38;5;250m" # Gray: Unknown
 MODEL_ICON="❓"
 MODEL_TIER="UNKNOWN"
 ;;
esac
SWITCH FREQUENCY INDICATOR
if [ $switch_count -eq 0 ]; then
 SWITCH_STATUS="stable"
 SWITCH_COLOR="\[38;5;46m" # Green: No switches
elif [ $switch_count -le 3 ]; then
 SWITCHSTATUS="${switchcount} switches"
 SWITCH_COLOR="\[38;5;226m" # Yellow: 1-3 switches
else
 SWITCHSTATUS="${switchcount} switches!"
 SWITCH_COLOR="\[38;5;196m" # Red: 4+ switches (frequent switching)
fi
GET LAST 3 SWITCHES FOR MINI-HISTORY
lastswitches=$(tail -n 3 "$HISTORYFILE" | grep '→' | cut -d'|' -f2 | tr '\n' ' ' | sed 's/ $//')
if [ -n "$last_switches" ]; then
 HISTORYDISPLAY="| ${lastswitches}"
else
 HISTORY_DISPLAY=""
fi
RESET="\[0m"
OUTPUT STATUSLINE
echo -e "${MODELICON} ${MODELCOLOR}${MODELTIER}${RESET} | ${SWITCHCOLOR}${SWITCHSTATUS}${RESET} ${HISTORYDISPLAY}"
KEY FEATURES
? Real-time model detection for Opus, Sonnet, and Haiku variants
? Switch count tracking showing total model changes in session
? Last 3 switches mini-history showing transition patterns (Opus→Sonnet→Haiku)
? Color-coded model tiers (magenta Opus, blue Sonnet, green Haiku)
? Switch frequency warnings (green stable, yellow 1-3, red 4+ switches)
? Persistent history storage per session in ~/.claude-code-model-history
? Cost awareness through model tier visualization
? Automatic switch event logging with timestamps
CONFIGURATION
Format: bash
Refresh Interval: 1000ms
Position: left
USE CASES
? Cost optimization by tracking Opus vs Sonnet vs Haiku usage patterns
? Identifying unnecessary model switching that inflates costs
? Understanding which tasks require which model tier
? Budget management through model tier awareness
? Debugging unexpected model changes in Claude Code settings
? Analyzing session patterns for optimal model selection strategy
TROUBLESHOOTING
1) Model always showing UNKNOWN despite valid Claude model running
 Solution: Check model.displayname field: echo '$input' | jq .model.displayname. Script matches case-insensitively on 'Opus', 'Sonnet', 'Haiku' keywords. If model name doesn't contain these (e.g., 'claude-3-5-sonnet-'), add custom matching: 'claude-3-5-sonnet') MODEL_TIER='SONNET'. Verify field exists and has expected format.
2) Switch count not incrementing when changing models
 Solution: Verify sessionid is consistent: echo '$input' | jq .sessionid. Each session has separate history file. If sessionid changes, switch count resets (expected). Check history file exists: ls ~/.claude-code-model-history/${sessionid}.history. Manually test: echo 'Opus' > file.history && echo '0' >> file.history.
3) Permission denied when creating model history directory
 Solution: Ensure HOME environment variable is set: echo $HOME. Check write permissions: mkdir -p ~/.claude-code-model-history. If permission denied, change location: HISTORY_DIR='/tmp/claude-model-history-$(whoami)'. Verify statusline script runs with correct user permissions.
4) Last 3 switches history not displaying transitions
 Solution: History format is 'timestamp|ModelA→ModelB' (e.g., '|Opus→Sonnet'). Check file content: tail ~/.claude-code-model-history/${session_id}.history. Grep filter looks for '→' character - ensure terminal encoding supports Unicode arrow. Alternative: replace → with ASCII '->' in script.
5) Switch frequency showing incorrect count
 Solution: Switch count stored on line 2 of history file. Verify: sed -n '2p' ~/.claude-code-model-history/${sessionid}.history. Count only increments when currentmodel != previousmodel AND previousmodel is not empty. New sessions start at 0 (expected). Manually reset: echo '0' to line 2 if corrupted.
TECHNICAL DETAILS
Documentation: https://docs.claude.com/en/docs/claude-code/statusline
PREVIEW
🎵 SONNET | 2 switches | Opus→Sonnet Haiku→Sonnet


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Source: Claude Pro Directory
Website: https://claudepro.directory
URL: https://claudepro.directory/statuslines/model-switch-history-tracker

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