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 evmts/tevm --skill upgrade-viemgit clone --depth 1 https://github.com/evmts/tevmWrote 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/evmts/tevm/upgrade-viem)<a href="https://agentmods.dev/skills/evmts/tevm/upgrade-viem"><img src="https://agentmods.dev/badge/skills/evmts/tevm/upgrade-viem/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/evmts/tevm/upgrade-viem"><img src="https://agentmods.dev/badge/skills/evmts/tevm/upgrade-viem.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- 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 | $0.00000 | $0.00407 |
| Opus 5.5 | $0.00000 | $0.00163 |
| Sonnet 5.5 | $0.00000 | $0.00081 |
| Haiku 4.5 | $0.00000 | $0.00041 |
Grade A, and why
upgrade-viem 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.
What it actually says
Upgrade viem
Input: optionally a target viem version. Without one, use the latest release on npm.
viem is both a dependency and a peer dependency across the workspace. An upgrade is complete only when every range agrees and every test passes.
- Find every manifest that lists
viemunderdependencies,devDependencies, orpeerDependencies(grep -l '"viem"' */package.json */*/package.json). Bump each range to the target version. Peer ranges use the same caret form the manifest already uses. - Run
pnpm installsopnpm-lock.yamlresolves the new version. Do not hand-edit the lockfile. - Read the viem changelog between the old and new versions. List every
breaking change that touches an API this repo calls (transports, actions,
defineChain, error classes, formatters). - Run the tree-wide typecheck. Fix compile errors caused by the upgrade in the packages that own them; do not loosen types to make errors go away.
- Run the tree-wide tests. Snapshot diffs that are only a version string are expected: update them. A snapshot whose content changes from a successful result to an error, or whose values change without a viem changelog entry explaining why, is a regression: fix the code, not the snapshot, and say so in the PR body.
- Add one
patchchangeset naming every package whose manifest changed, unless a breaking viem change surfaces through tevm's public types, in which case the changeset isminorand names the affected exports.
PR title: ⬆️ chore(deps): upgrade viem to <version>. Body: the version
range, the breaking changes considered, and every snapshot that changed with
the reason. Keep unrelated dependency bumps out of this PR.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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 First seen · 32 lines · 0 tokens per session scan A 847089ab6d2c
upgrade-viem is a skill published in the GitHub repository evmts/tevm (449 stars, last pushed 2mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 407 tokens. 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 2026-09-07.
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