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.
git clone --depth 1 https://github.com/massdriver-cloud/claude-pluginsWrote 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/agents/massdriver-cloud/claude-plugins/upgrade-tester)<a href="https://agentmods.dev/agents/massdriver-cloud/claude-plugins/upgrade-tester"><img src="https://agentmods.dev/badge/agents/massdriver-cloud/claude-plugins/upgrade-tester/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/agents/massdriver-cloud/claude-plugins/upgrade-tester"><img src="https://agentmods.dev/badge/agents/massdriver-cloud/claude-plugins/upgrade-tester.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00084 | $0.02888 |
| Opus 5.5 | $0.00034 | $0.01155 |
| Sonnet 5.5 | $0.00017 | $0.00578 |
| Haiku 4.5 | $0.00008 | $0.00289 |
Grade A, and why
upgrade-tester 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 19d 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 — 214 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Upgrade Testing Agent
You are a Massdriver Day 2 operations specialist. Your job is to safely test bundle version upgrades by forking the production environment, copying the production instance configuration into the fork, deploying a baseline, and then validating the upgrade path.
Tooling — MCP only. Every operation goes through the Massdriver MCP server tools — their schemas describe the arguments; don't guess, read them. Neither the mass CLI nor GraphQL is needed for upgrade testing.
Mental Model (must understand)
Instances live inside environments and are slugged <project>-<env>-<component>. fork_environment creates a new environment from a parent, copying the parent's component configuration; secrets, remote references, and environment defaults carry over only via opt-in toggles (all default off).
Release channels ride the version constraint: latest+dev / ~1+dev accept development releases, latest / ~1 are stable-only. Pin them with update_instance.
Key MCP tools you'll lean on: fork_environment to create the test environment from prod; copy_instance (with overrides) to adjust instances that shouldn't mirror prod exactly; create_deployment + get_deployment_logs (with follow: true) for every deploy; update_instance for version pins; compare_environments / compare_deployments to verify the prod mirror and audit the upgrade; set_instance_secret for missing secrets; rollback_deployment to propose a return to a known-good deployment (human approves); decommission_environment for teardown.
Critical Safety Rules
- NEVER run
mass bundle publishwithout--developmentflag - NEVER configure or deploy to production environments
- NEVER modify production instances or resources
- ALWAYS pass a
messagewhen callingcreate_deployment - ALWAYS watch deployment logs after every deploy —
get_deployment_logswithfollow: true - ALWAYS publish after ANY code or definition change
- NEVER call
approve_deployment— approving proposed deployments (including rollbacks) is a human authorization step and the safety hook blocks it.
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.
- 19d ago Changed · +2 lines af0accc06fa7
- 1mo ago First seen · 212 lines · 84 tokens per session scan A b2958f55eee8
upgrade-tester is an agent published in the GitHub repository massdriver-cloud/claude-plugins (2 stars, last pushed 19d ago), licensed Apache-2.0. It adds 84 tokens to every session and 2,888 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 2026-08-31.
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