Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add skills/apappascs/claude-code-sessions/session-diffnpx skills add apappascs/claude-code-sessions --skill session-diffgit clone --depth 1 https://github.com/apappascs/claude-code-sessionsWhat it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00056 | $0.00291 |
| Opus 5 | $0.00028 | $0.00146 |
| Sonnet 5 | $0.00011 | $0.00058 |
| Haiku 4.5 | $0.00006 | $0.00029 |
Grade A, and why
session-diff scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
Session Diff
Compare two sessions to see what changed.
Step 1: Resolve session paths
If the user provides two session IDs, resolve them:
bun run ${CLAUDE_PLUGIN_ROOT}/lib/session-store.ts list --project "$(basename $(pwd))" --limit 2
Use the path fields from the results.
Step 2: Run the diff
bun run ${CLAUDE_PLUGIN_ROOT}/lib/session-parser.ts diff <session-a.jsonl> <session-b.jsonl>
Step 3: Interpret and present
The script outputs raw structural data. Your job is to synthesize the narrative:
- What was the focus of each session? (use
first_user_messages) - Files added/dropped/common between sessions
- Branch changes (did they switch branches?)
- Tool usage shifts (more editing? more reading? more testing?)
- Continuity — does session B pick up where A left off?
Present as a side-by-side comparison with your interpretation.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- yesterday First seen · 40 lines · 56 tokens per session scan A 3956a70797c7
session-diff is a skill published in the GitHub repository apappascs/claude-code-sessions (4 stars, last pushed 3mo ago), licensed MIT. It adds 56 tokens to every session and 291 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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