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/marcusrbrown/dev-like/develop-like-37signalsnpx skills add marcusrbrown/dev-like --skill develop-like-37signalsgit clone --depth 1 https://github.com/marcusrbrown/dev-likeWrote 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/marcusrbrown/dev-like/develop-like-37signals)<a href="https://agentmods.dev/skills/marcusrbrown/dev-like/develop-like-37signals"><img src="https://agentmods.dev/badge/skills/marcusrbrown/dev-like/develop-like-37signals.svg" alt="Measured on agentmods" 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 | $0.00084 | $0.01565 |
| Opus 5 | $0.00042 | $0.00783 |
| Sonnet 5 | $0.00017 | $0.00313 |
| Haiku 4.5 | $0.00008 | $0.00156 |
Grade A, and why
develop-like-37signals 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 3d 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 — 89 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Develop like 37signals
Profiled as of 2026-07-16 · consent tier: self-published · full bibliography in references/sources.md. Cultures drift — if this is more than ~6 months old, re-run
/dev-like 37signalsto refresh.
Core principle
Fixed appetite, variable scope — decide how much time a problem is worth before you decide what to build, then build to that budget instead of estimating a spec [Shape Up ch.1]. Work happens in six-week cycles with a two-week cooldown between them, and all teams share the same cadence [how we work].
Principles
- Fixed appetite, variable scope — decide the time budget before the solution [Shape Up ch.1]
- Six-week cycles with a two-week cooldown, no exceptions across teams [how we work]
- No backlogs — shape and bet, don't queue [Shape Up ch.8]
- Hand over whole projects, not task lists; done means deployed [Shape Up ch.10]
- Circuit breaker — cancel by default rather than extend a project past its cycle [Shape Up ch.8]
- Show progress on a hill (uphill/downhill), not with estimates or percentages [Shape Up]
- Vanilla Rails, server-rendered, minimal dependencies — fight hard before adding a gem or a JS package [vanilla Rails stack]
- Manual, guided exploratory QA over exhaustive test-case matrices [all about QA]
- Coding is craft, not overhead to delegate away — pair with AI, don't hand it the keyboard [coding should be a vibe]
Workflow
What ships with it
4 files 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.
- 3d ago First seen · 89 lines · 84 tokens per session scan A 9e7e029ad3e8
develop-like-37signals is a skill published in the GitHub repository marcusrbrown/dev-like (2 stars, last pushed 3d ago), licensed MIT. It adds 84 tokens to every session and 1,565 once invoked, about $0.0004 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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