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/tellahq/opensession/simplifynpx skills add tellahq/opensession --skill simplifygit clone --depth 1 https://github.com/tellahq/opensessionWhat 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 | $0.00037 | $0.00744 |
| Opus 5 | $0.00018 | $0.00372 |
| Sonnet 5 | $0.00007 | $0.00149 |
| Haiku 4.5 | $0.00004 | $0.00074 |
Grade A, and why
simplify 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 2d ago.
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.
How it starts
The opening of the file, as written. The whole thing — 77 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Simplify
/simplify → 4 cleanup agents in parallel → apply the fixes
You are improving the quality of the changed code, not hunting for bugs. Review it for reuse, simplification, efficiency, and altitude issues, then fix what you find. Do not look for correctness bugs — that is what a code review is for.
Phase 0 — Establish the diff
If $ARGUMENTS names a target (a path, a commit, a ref range, a PR number),
treat it as scope guidance and establish the diff from it. Otherwise review the
current change:
- Working-tree changes:
git diff HEAD(plusgit status --shortfor new files). - If the working tree is clean, the branch's committed diff:
git diff @{upstream}...HEAD, falling back togit diff origin/main...HEADwhen there is no upstream.
Read the diff, and read enough of each enclosing function or file to judge the change in context. If the diff is empty, say so and stop.
Phase 1 — Review (4 cleanup agents in parallel)
Launch 4 independent review agents via the task tool (subagent_type: "explore"), all in a single message so they run concurrently. Pass each
agent the diff, the files it touches, and exactly one of the four angles below.
Each returns its findings with file, line, a one-line summary, and the
concrete cost (what is duplicated, wasted, or harder to maintain).
Reuse
Flag places the diff re-implements something the codebase already has — grep shared/utility modules and files adjacent to the change, and name the existing helper to call instead.
Simplification
Flag unnecessary complexity the diff adds: redundant or derivable state, copy-paste with slight variation, deep nesting, dead code left behind. Name the simpler form that does the same job.
Efficiency
Flag wasted work the diff introduces: redundant computation or repeated I/O, independent operations run sequentially, blocking work added to startup or hot paths. Also flag long-lived objects built from closures or captured environments — they keep the entire enclosing scope alive for the object's lifetime (a memory leak when that scope holds large values); prefer a class/struct that copies only the fields it needs. Name the cheaper alternative.
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.
- 2d ago First seen · 77 lines · 37 tokens per session scan A 4d0d0c03f559
simplify is a skill published in the GitHub repository tellahq/opensession (327 stars, last pushed 2d ago), licensed MIT. It adds 37 tokens to every session and 744 once invoked, about $0.0002 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 2026-08-30.
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