browser4-coding

name	browser4-coding
title	browser4-coding
tier	procedure
description	Create and validate Browser4 plugins, skills, JS scripts, and shell scripts; and develop Browser4 ITSELF (self-development): build modules, extract live skeletons, analyze impact, plan dev tasks, and check CDP pitfalls. Use when the user asks to write a Browser4 plugin or skill, write browser JS or build scripts, modify Browser4's own Kotlin/Rust code, or validate repo consistency.
allowed-tools	coding.scaffold coding.scaffoldFlow coding.scaffoldFromExample coding.validate coding.write coding.read coding.replace coding.replaceRegex coding.editLines coding.insertAfter coding.revert coding.shell coding.mvnBuild coding.ktSymbols coding.ktReferences coding.ktInheritance coding.impact coding.moduleGraph coding.devTask coding.trapCheck coding.protect coding.tokenStats coding.estimateTokens tab.eval tab.console

browser4-coding

Quick Start

Create and validate a plugin, or a skill:

coding.scaffold(type="plugin", pluginName="My Plugin", domain="media",
                basePackage="ai.platon.pulsar.myplugin",
                toolMethod="detectMedia", toolDescription="Detect media on the page")
coding.validate(type="plugin", path="browser4-plugins/browser4-myplugin")

coding.scaffold(type="skill", name="my-skill", description="What it does")
coding.validate(type="skill", path="skills/my-skill/SKILL.md")

For self-development work (modifying Browser4 itself), start with coding.scaffoldFlow — see Workflows below.

The programming-agent kernel for Browser4: sandboxed shell + filesystem, artifact scaffolding/validation (plugins, skills, browser JS, scripts), and a full self-development toolset for modifying Browser4's own code (live module graph, impact analysis, Maven builds with structured diagnostics, CDP pitfall awareness, high-level dev-task planning).

When to Use

• User wants to create a new Browser4 plugin, skill (SKILL.md), browser JS script, or build/deploy/run script
• User wants to validate any of the above
• User wants to modify Browser4's own code (Kotlin modules, Rust CLI, poms) — use the self-development tools below
• User wants to check repo governance (versions, module registration) or the CDP pitfalls before editing the browser driver

How It Works

The coding tools fall into three layers: artifact tools generate and validate plugins, skills, JS, and scripts (templates from real code so they never go stale); self-development tools inspect and modify Browser4 itself (live module graph, impact analysis, Maven builds, CDP trap checks); and shell/filesystem tools provide a sandboxed environment for anything else.

Patterns

1. Create and validate a new plugin

coding.scaffold(type="plugin", pluginName="...", domain="...", basePackage="...", toolMethod="...", toolDescription="...")
coding.validate(type="plugin", path="browser4-plugins/browser4-xxx")
coding.mvnBuild(module="browser4-plugins/browser4-xxx")

2. Copy an existing plugin's structure

coding.scaffoldFromExample(path="browser4-plugins/browser4-seo")
coding.validate(type="plugin", path="browser4-plugins/browser4-xxx")

3. Repo governance check before merging

coding.validate(type="repo-consistency")

Flags

coding is a tool set, not a CLI — there are no command-line flags. Tool parameters are documented per tool in the sections below.

Errors & Recovery

Symptom	Cause	Fix
coding.validate fails	Missing/incorrect required parameters	Read the validation output and fix the named field
coding.mvnBuild fails	Compile errors in generated code	Read the structured diagnostics and fix the faulty file
scaffoldFromExample renames wrong classes	Ambiguous class stem	Pass explicit per-class keys (e.g. SeoService=CustomService)

Artifact Tools (plugins / skills / js / scripts)

coding.scaffold

Generate a template for any of the four artifact types.

Type	Required Parameters	Optional Parameters
plugin	pluginName, domain, basePackage, toolMethod, toolDescription	pdkVersion (defaults to the repo VERSION file)
skill	name (must equal directory name), description (1-1024 chars)	triggers (comma-separated), tools (comma-separated → allowed-tools)
js	name	purpose (extract, inject, interact)
script	name	scriptType (build, deploy, run), shell (ps1, bash)

coding.validate

Validate an artifact — or the whole repo (type="repo-consistency", no path).

Type	Path Meaning	What It Checks
plugin	Plugin base directory	pom.xml (parent browser4-pdk, literal version, required deps), plugin.json (PluginManifest schema), AutoConfiguration implements ToolMount, ToolExecutor structure, manifest.name == artifactId
skill	SKILL.md file path	YAML frontmatter name + description (1-1024), name == directory name, allowed-tools, tool-reference cross-check
js	.js file path	Bracket balance, return statement, use strict, anti-patterns
script	.ps1/.sh file path	param block, shebang, error handling
repo-consistency	(none)	VERSION format; VERSION == root pom == BOM version; every default <module> dir exists; on-disk module dirs registered in the root pom

coding.scaffoldFromExample — anti-staleness live templates

Generate a skeleton from EXISTING real code instead of hand-written templates (which go stale):

• Single file: parameterizes basePackage/className/domain/toolMethod into {placeholders}; omit rename args to see discovered parameters.
• Directory (plugin/module): extracts a MULTI-FILE skeleton set with cross-file-consistent renames — basePackage = common package prefix (per-file .tools/.config suffixes preserved), artifactId from pom.xml (parent BOM excluded), pluginName from plugin.json. Renaming className (or passing stem=<NewStem>) derives sibling classes sharing the detected class stem (Seo → Weather renames SeoToolExecutor and SeoAutoConfiguration/SeoService/SeoConfig). Explicit per-class keys (SeoService=CustomService) always win.

coding.scaffoldFlow — multi-file dev-flow skeletons

type: b4-cli-command (commands.rs CommandDef + MCPToolController alias + backend + test), agent-tool (ToolExecutor + ToolMount auto-config), rest-endpoint (Controller + Service + test), test-class, skill. All identifiers derive from one name; verify=true runs the type-appropriate build check.

Self-Development Tools (modifying Browser4 itself)

coding.moduleGraph — live module graph

Scans the repo's real pom.xml files (module path, artifactId, parent, internal deps) and reports the graph; warns when it drifted from the static snapshot (e.g. browser4-pdk, plugins, test modules). module=<path> reports transitive dependents + suggested test commands. This is the anti-staleness answer to a hand-maintained module map.

coding.impact(path=...)

Which module owns a file, which modules are affected transitively (from the LIVE pom graph), and suggested test commands. Run before modifying Browser4's own code.

coding.mvnBuild(module=..., goals=...)

mvn -pl <module> -am <goals> with structured Kotlin/Java compiler diagnostics instead of raw logs — the fast, dependency-free alternative to a Kotlin LSP server. Use to check code after edits (goals default compile, skipTests=true).

coding.ktSymbols / coding.ktReferences / coding.ktInheritance

Zero-dependency Kotlin analysis: symbols (classes/functions/properties), references (scope='file' default, or scope='module' for a cross-file scan that excludes the declaring file), and the inheritance chain (ktInheritance(path, className?) walks the primary supertype across the module's files). Use before refactoring to assess impact without starting a JDTLS server.

coding.devTask(task=..., verify=..., runTests=...)

High-level entry: parse a natural-language dev task into an executable plan following the AGENTS.md flow — locate files → impact → mvnBuild compile → smallest-scope tests → trapCheck (driver code) → repo-consistency → commit guidance. Module mentions resolve against the LIVE pom graph when available. verify=true runs the fast checks (compile, trapCheck, repo-consistency); runTests=true (with verify) also runs the module's test suite — scoped to -Dtest=<FooTest> when the task names a test class. module= overrides the inferred module.

coding.trapCheck(path=...)

Scan a file for the three known Browser4 CDP pitfalls (AGENTS.md): mouseWheel race (crbug.com/444929150), cursor positioning after focus+click, Input.insertText racing. Run before editing browser-driver code (PulsarWebDriver.kt and friends).

coding.protect(path=..., on=...)

Session-level dynamic file protection: coding.protect(path="src/Foo.kt", on=true) blocks delete/replace/editLines/insertAfter on that exact file; on=false removes it; coding.protect() lists dynamic protections. Repo-governance defaults (VERSION/AGENTS.md/CLAUDE.md/root pom/BOM/CI) are always protected and cannot be unprotected.

Shell & Filesystem Tools

• coding.shell(command, timeoutSeconds?, workingDir?) — execute allowed dev commands (git/cargo/mvn/npm/python/...)
• File ops: read, readLines, write, append, replace, replaceRegex, editLines, insertAfter, revert, delete, mkdir, copy, move, stat, diff (myers/patience)
• Search: glob, grep (skip excluded dirs), languages
• Repo governance protection: delete/replace/editLines/insertAfter are BLOCKED for VERSION, AGENTS.md, CLAUDE.md, root pom.xml, browser4-dependencies/pom.xml (BOM), .github/workflows/ci.yml — do not try to work around this; ask the user for explicit intent instead. Add session-level protections with coding.protect(path, on).
• coding.runCode(language, code) — sandboxed snippet execution (kotlin/js/python/bash)
• LSP: diagnostics(path), symbols(pattern?), references(path, symbol), lspServers — per-language servers (ts/js/py/rs), started on demand, requires the server installed; degrade gracefully when missing
• coding.tokenStats(reset?) — per-method token usage of coding tool calls so far (calls/errors/input/output tokens, avg/max output); use to audit context-window consumption. coding.estimateTokens(text) — heuristic token count of any text before sending it.

Workflows

Creating a Browser4 Plugin

1. coding.scaffold(type="plugin", pluginName="browser4-xxx", domain="xxx",
     basePackage="ai.platon.pulsar.xxx", toolMethod="doXxx",
     toolDescription="Does xxx on the page")

2. coding.write(path=<file>, content=<from scaffold>) ... write each file

3. coding.validate(type="plugin", path="browser4-plugins/browser4-xxx") → fix issues

4. coding.mvnBuild(module="browser4-plugins/browser4-xxx") → compile to verify

5. If compile fails: coding.read the error file → coding.replace → recompile

Cloning an existing plugin (anti-staleness)

1. coding.scaffoldFromExample(path="browser4-plugins/browser4-seo")
   → Discovery mode: shows basePackage/className/domain/toolMethod/artifactId/stem

2. coding.scaffoldFromExample(path="browser4-plugins/browser4-seo",
     className="WeatherToolExecutor", basePackage="ai.platon.pulsar.weather",
     domain="weather", artifactId="browser4-weather")
   → Multi-file skeleton; sibling classes (WeatherAutoConfiguration/WeatherService)
     follow the stem rename automatically

3. coding.write each generated file → coding.mvnBuild → coding.validate(type="plugin")

Modifying Browser4's own code (recommended order)

1. coding.impact(path=<file>)      → owning module + affected modules + test commands
2. coding.read the file            → understand the code
3. coding.trapCheck(path=<file>)   → CDP pitfalls if browser-driver code
4. Make the edit (coding.replace / coding.editLines / coding.write)
5. coding.mvnBuild(module=<module>) → compile check
6. coding.shell(command=<smallest test scope>) → run tests
7. coding.validate(type="repo-consistency") → governance still consistent
8. coding.moduleGraph() → confirm no module-graph drift

Creating a Skill / JS Script / Build Script

# Skill
1. coding.scaffold(type="skill", name="my-skill", description="...", triggers="...", tools="coding.read,tab.eval")
2. coding.write(path="skills/my-skill/SKILL.md", content=<from scaffold>)  # dir name MUST equal name
3. coding.validate(type="skill", path="skills/my-skill/SKILL.md")

# Browser JS
1. coding.scaffold(type="js", name="extract-prices", purpose="extract")
2. coding.write(path="scripts/extract-prices.js", content=<from scaffold>)
3. coding.validate(type="js", path="scripts/extract-prices.js")
4. tab.eval(expression=<read the JS file>) → tab.console() → iterate

# Build script
1. coding.scaffold(type="script", name="build", scriptType="build", shell="ps1")
2. coding.write(path="build.ps1", content=<from scaffold>)
3. coding.validate(type="script", path="build.ps1") → coding.shell(command="powershell -File build.ps1")

Notes

• The generated plugin AutoConfiguration implements ToolMount, so PluginManager registers the plugin's tools into CustomToolRegistry automatically.
• plugin.json follows the real PluginManifest schema (name/version/description/dependsOn/autoConfigurationClasses).
• The coding module is intentionally independent of pulsar-common; heavy backends (kotlin-compiler-embeddable, LSP servers) are probed at runtime and NEVER downloaded/loaded by default — tools degrade gracefully when unavailable.