Happier is an open-source, end-to-end encrypted client that lets people run AI coding-agent sessions on a computer and continue controlling them from a phone, browser, or desktop app. It is for developers who use agents such as Claude Code, Codex, Gemini, or OpenCode across multiple devices, with self-hosting available. The catalogue entries are add-ons for configuring or extending this client and its supported coding-agent 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.
git clone --depth 1 https://github.com/happier-dev/happierWrote 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/happier-dev/happier/e2e-tests-engineer)<a href="https://agentmods.dev/agents/happier-dev/happier/e2e-tests-engineer"><img src="https://agentmods.dev/badge/agents/happier-dev/happier/e2e-tests-engineer/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/happier-dev/happier/e2e-tests-engineer"><img src="https://agentmods.dev/badge/agents/happier-dev/happier/e2e-tests-engineer.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 | $0.00024 | $0.00066 |
| Opus 5.5 | $0.00010 | $0.00026 |
| Sonnet 5.5 | $0.00005 | $0.00013 |
| Haiku 4.5 | $0.00002 | $0.00007 |
Grade A, and why
e2e-tests-engineer 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
Deprecated
This custom subagent definition is disabled for this repository. Use AGENTS.md and .agents/skills/happier-testing for e2e workflow.
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 3b2e92030a7a
- 1mo ago First seen · 9 lines · 24 tokens per session scan A 55af4b0fde48
e2e-tests-engineer is an agent published in the GitHub repository happier-dev/happier (1,971 stars, last pushed yesterday), licensed MIT. It adds 24 tokens to every session and 66 once invoked, about $0.0001 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 agents, from other repositories
test-engineer
Test strategy, integration/e2e coverage, flaky test hardening, TDD workflows.
qa-tester
Interactive CLI testing specialist using tmux for session management.
senior-qa
Senior QA engineer for acceptance tests. Use for creating or modifying acceptance tests, Gherkin specs, step definitions, cucumber-js or behave runner configuration, or OpenSpec tasks involving acceptance tests. Follows the acceptance-test-authoring skill.
visual-qa
Read-only. Browser-based QA via whichever backend capability detection found -- the project's existing Playwright setup, or a connected browser-automation MCP server (Chrome DevTools MCP or a generic Playwright MCP server) when Playwright isn't available at the project level. Runs existing Playwright tests (or drives…
dev-agent-visual-qa
Read-only. Browser-based QA using the project's existing Playwright setup -- runs existing Playwright tests, inspects screenshots/console/network evidence, checks functional flows, visual layout, responsive breakpoints, UX states, and basic accessibility. Only invoked when Playwright is genuinely available in the…
frontend-test-runner
Post-commit frontend test execution — unit, component, e2e, coverage.