playwright-test-coverage

An automated workflow for creating test coverage with Playwright, a browser-testing tool. It plans test cases, generates tests for them, runs the tests, and asks another agent to fix failures one at a time.

In plain words
What is it for?
Use it to build Playwright test plans and test cases from a task or optional seed file, then run and repair those tests.
Why use it?
It organizes the otherwise separate work of deciding what to test, writing the tests, and repairing failures. A test plan can be saved under the project's specs folder.

Agent

Install

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.

agentmods
npx agentmods add agents/microsoft/playwright/playwright-test-coverage
Clone the repo
git clone --depth 1 https://github.com/microsoft/playwright
Per session 3 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 323 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00003 $0.00323
Opus 5 $0.00002 $0.00161
Sonnet 5 $0.00001 $0.00065
Haiku 4.5 $0.00000 $0.00032

Measured 2d ago against content hash 8e8a32e98c70, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

playwright-test-coverage 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 2d 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.

packages/playwright/src/agents/playwright-test-coverage.prompt.md · 32 lines

What it actually says

Parameters:

  • Task: the task to perform
  • Seed file (optional): the seed file to use, defaults to ${seedFile}
  • Test plan file (optional): the test plan file to write, under specs/ folder.
  1. Call #playwright-test-planner subagent with prompt:
  1. For each test case from the test plan file (1.1, 1.2, ...), one after another, not in parallel, call #playwright-test-generator subagent with prompt:
  1. Call #playwright-test-healer subagent with prompt:

Run all tests and fix the failing ones one after another.

Changes

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.

  1. 2d ago First seen · 32 lines · 3 tokens per session scan A 8e8a32e98c70

Subscribe to this mod's changes

playwright-test-coverage is an agent published in the GitHub repository microsoft/playwright (95,378 stars, last pushed 4d ago), licensed Apache-2.0. It adds 3 tokens to every session and 323 once invoked, about $0.0000 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 2026-08-30.

Related

Other agents, from other repositories