Analyze which Claude Code tools appear together in the same session — co-occurrence and affinity.
npx cc-pair
Zero dependencies. Reads ~/.claude/projects/ directly.
cc-pair — Tool Co-occurrence Analyzer
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Sessions: 1,837 (≥5 tool calls)
Tool Presence Rate (% of sessions using this tool)
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Read ████████████████████ 86.6%
Bash ████████████████░░░░ 75.4%
Grep ██████████░░░░░░░░░░ 49.6%
Glob █████████░░░░░░░░░░░ 45.2%
Write █████░░░░░░░░░░░░░░░ 24.0%
Edit ████░░░░░░░░░░░░░░░░ 20.7%
WebSearch ██░░░░░░░░░░░░░░░░░░ 12.1%
WebFetch ██░░░░░░░░░░░░░░░░░░ 11.4%
Top 10 Tool Pairs (by session count)
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Bash + Read ████████████████████ 1,250 (68.0%)
Grep + Read ██████████████░░░░░░ 905 (49.3%)
Glob + Read █████████████░░░░░░░ 823 (44.8%)
Bash + Grep ███████████░░░░░░░░░ 671 (36.5%)
Bash + Glob ███████████░░░░░░░░░ 643 (35.0%)
Glob + Grep █████████░░░░░░░░░░░ 547 (29.8%)
Bash + Write ████████░░░░░░░░░░░░ 430 (23.4%)
Bash + Edit ██████░░░░░░░░░░░░░░ 368 (20.0%)
Edit + Read ██████░░░░░░░░░░░░░░ 359 (19.5%)
Read + Write ██████░░░░░░░░░░░░░░ 438 (23.8%)
Top 10 Tool Affinities (co-occur more than expected by chance)
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TaskCreate + TaskUpdate ████████████████████ 13.63x (122 sessions)
WebFetch + WebSearch ██████████████░░░░░░ 6.33x (195 sessions)
Edit + ExitPlanMode ███████████░░░░░░░░░ 4.78x (73 sessions)
Edit + TaskCreate ██████████░░░░░░░░░░ 4.38x (42 sessions)
Edit + TodoWrite █████████░░░░░░░░░░░ 4.18x (41 sessions)
- Read + Bash = 68% of sessions — the fundamental working pair of Claude Code
- TaskCreate + TaskUpdate: 13.63x — they always travel together. Creating tasks without updating them never happens
- WebFetch + WebSearch: 6.33x — web research always uses both: search first, then fetch the pages
- Edit always co-occurs with Read (100%) — Edit never appears in a session without Read. Always read before you edit.
- Grep + Glob together (29.8%) — the exploration duo. Find files AND search content
- Agent appears in only 0.2% of sessions — subagents are extremely rare in practice
| Tool | Always comes with | Partnership meaning |
|---|---|---|
| Read | Bash (87%), Grep (57%) | Reading is the universal partner |
| Edit | Read (100%), Bash (93%) | Always read first, always verify after |
| TaskCreate | TaskUpdate (98%) | Create and update are inseparable |
| WebSearch | WebFetch (88%) | Search leads to fetching |
| ExitPlanMode | Read (99%), Edit (99%) | Planning transitions directly to action |
npx cc-pair --tool=Edit # all partners for Edit
npx cc-pair --tool=WebSearch # all partners for WebSearchnpx cc-pair --json # Raw JSON output
npx cc-pair --tool=<name> # Partners for a specific tool
yurukusa.github.io/cc-pair — drag and drop your projects folder. Includes an interactive affinity heatmap.
Part of cc-toolkit — tools for understanding your Claude Code sessions.
Claude Code Ops Kit ($19) — 16 production hooks + 5 templates + 3 tools. Built from 160+ hours of autonomous operation.
Source: yurukusa/cc-pair