Hmbown/CodeWhale is an open-source coding agent that runs in the terminal and is written in Rust. Developers use it to inspect repositories, edit files, run commands, and coordinate work with configurable model providers, skills, MCP servers, and approval controls; the catalogue entries extend its available workflows.
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 skills add Hmbown/CodeWhale --skill handoffgit clone --depth 1 https://github.com/Hmbown/CodeWhaleWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/hmbown/codewhale/handoff)<a href="https://agentmods.dev/skills/hmbown/codewhale/handoff"><img src="https://agentmods.dev/badge/skills/hmbown/codewhale/handoff/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/hmbown/codewhale/handoff"><img src="https://agentmods.dev/badge/skills/hmbown/codewhale/handoff.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Snyk warn
- NVIDIA SkillSpector pass
What 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 5.1 | $0.00070 | $0.01207 |
| Opus 5.5 | $0.00028 | $0.00483 |
| Sonnet 5.5 | $0.00014 | $0.00241 |
| Haiku 4.5 | $0.00007 | $0.00121 |
Grade A, and why
handoff 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 1mo 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 — 93 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Handoff
Write a compact, decision-ready handoff so the next session (or the user) can continue without reconstructing the current one. Use when the session is ending, context is running low, the user asks for a handoff / "pass the baton" / "hand off", or a long-running operation needs a durable state checkpoint. The goal: the durable artifact survives, the context does not need to.
Invocation: model+user
When to use
- The user says "handoff", "hand off", "pass the baton", "takeover prompt", "write me a handoff", or the session is about to end / compact.
- A long operation (multi-turn, multi-workstream) has state that must survive context loss: commits, branches, PRs, CI, blockers, decisions.
- You are switching to a fresh session and want the new session to start from evidence instead of reconstructing the old one.
What to do
-
Gather the truth from tools, not memory. Run/collect:
git branch --show-current,git status --short,git log --oneline origin/<default>..HEAD(what is local-only),git log --oneline -5(recent context).- Live remote state where relevant (
gh pr list --state open,gh pr checks <n>,gh run list) — only what the user's operation actually depends on; do not pad the handoff with a full GitHub dump. - Any in-flight work: dirty files, uncommitted slices, partial worktrees, running background jobs/workers, queued CI.
-
Write a compact markdown handoff (aim under ~60 lines; the user may also ask for a "short text-only" variant — then aim under ~15 lines):
# Handoff — <operation/session name> — <date> - **State:** <one-line: what is done vs in-flight vs blocked> - **Landed/committed:** <exact SHAs + one-line what> - **Branches/PRs:** <names + states; which are ours vs community> - **CI:** <what is green, what is waiting, what is broken> - **Blockers:** <exact blocker + what would unblock> - **Decisions made:** <the WHY that a fresh session must not re-litigate> - **Next step:** <the single next action, one line> - **Continuation records:** <pointers to partial work that must be preserved (worktrees, uncommitted files, receipts)>
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.
- 1mo ago Changed · -5 lines bb7c8f293769
- 1mo ago First seen · 98 lines · 70 tokens per session scan A 8f809e2e32a7
handoff is a skill published in the GitHub repository Hmbown/CodeWhale (41,099 stars, last pushed yesterday), licensed MIT. It adds 70 tokens to every session and 1,207 once invoked, about $0.0003 per session on Opus 5.5. 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.
Other skills, from other repositories
forget
Help the user remove a stored fact using Codewhale's Context Lens when they ask to forget or delete a memory.
cw-land
Use when turning verified Codewhale work into commits, branches, or a merge: choosing direct-main vs. worktree vs. integration branch, preserving contributor credit, and honoring the gate artifact before merging.
cw-slice
Use before writing code for any Codewhale feature, upgrade, or refactor: find the existing owner of the behavior, bound the change to one reviewable slice, and fix the evidence bar before you start.
cw-dogfood
Use when a Codewhale change needs proving in the real product, or when asked to build/install/dogfood the local binaries: stamped release build, atomic install, fresh-shell verification, and the manual QA that gates cannot cover.
cw-gates
Use before claiming any Codewhale change is done, green, or ready to land: the focused-to-broad verification ladder, the budget checks CI enforces, and the rules for what counts as a passing test.
cw-handoff
Use when writing a Codewhale takeover prompt, continuation note, or end-of-session summary for another agent or a later session: a paste-ready handoff grounded in live state, with done/suspected/blocked kept separate.