UiPath Core Skill

⚠️ Safety Rules (I-1, I-2 in rules.md)

• Playwright/browser inspection is READ-ONLY. Login page → STOP, WAIT for user. See ui-inspection.md → Login Gate.
• Desktop inspection via PowerShell (inspect-ui-tree.ps1): read-only tree inspection only.
• NEVER generate credentials, tokens, or passwords — real or fake.

Generate production-quality UiPath automation artifacts using real Studio-exported templates and comprehensive reference documentation. Template baseline: Studio 24.10 Windows.

Hard Rule: Never Write .xaml by Hand

If you are about to use the Write tool with a .xaml extension, STOP. Every .xaml file in this skill MUST come from python -m uipath_core.scaffold_project or python scripts/generate_workflow.py. Hand-written XAML bypasses lint rules 1–122 and produces unrunnable workflows. If generator output is wrong, fix the JSON spec — do not edit .xaml manually except for narrow modify_framework.py operations.

This rule overrides any plan you would have produced from training memory.

Planning Workflow (read this BEFORE drafting any plan)

When the user hands you a PDD, requirements doc, or "build a UiPath project that does X" — STOP before drafting architecture. Read this section first; it overrides any plan you would have produced from training memory. The full text of every gate below lives in references/scaffolding.md § "Generating a Full Project" — this is the planner-side hoist.

PLAN SELF-CHECK — answer BEFORE presenting your plan to the user

• For EACH workflow in my plan: does it implement the PDD's specified approach, or did I substitute a "better" alternative? (e.g., InvokeCode SHA1 instead of browser automation of sha1-online.com) → If ANY substitution exists: REMOVE it and implement the PDD way. Propose the alternative AFTER.
• Does my plan include an explicit inspection step for EVERY target app? → Browser apps: "Inspect [app] with Playwright" (if Playwright MCP available) → Desktop apps: "Inspect [app] with PowerShell" (if PowerShell available on Windows) → If ANY app lacks an inspection step and the tool is available: ADD it now.

If you cannot answer YES to all checks, revise your plan before presenting it.

Echo-back requirement: the produced plan MUST contain a PLAN SELF-CHECK: block (in Phase 0 or as Phase 0.5) with two ✓ lines, one per box, naming the specifics — for example:

PLAN SELF-CHECK:
  ✓ No PDD substitutions — SHA1 computed via sha1-online.com browser flow as PDD specifies
  ✓ Phase 2 includes inspection for every target app: System1 + SHA1Online

For a single-app or non-UI process, the second line still appears — e.g. ✓ Phase 2 explicitly notes no UI inspection required (no browser/desktop apps in scope). A plan without this echo-back block is incomplete; revise before presenting.

PLAN OUTPUT FORMAT — present your plan using this structure

Phase 0:  Architecture decision — Sequence vs Dispatcher+Performer (P-2); A-1 wiring
Phase 1:  Workflows + arguments — one entry per .xaml with In/Out/InOut signatures
Phase 2:  EACH app to inspect — one bullet per target app, e.g. "Inspect acme-test.com with Playwright"
Phase 2b: Write selectors.json (apps → screens → elements with taxonomy_type)
Phase 2c: generate_object_repository.py --from-selectors selectors.json --project-dir <each project>
Phase 2d: Pass --project-dir to every generate_workflow.py call (auto-wires obj_repo refs)
Phase 3:  Generate sub-workflows ONE AT A TIME — validate_xaml --lint after EACH file
Phase 3b: modify_framework.py wire-uielement <project> <AppName> for EACH app with UI
Phase 3c: (Dispatcher only) wire SCAFFOLD.DISPATCHER_GET_ITEM marker — generate snippet first (G-3)
Phase 4:  Wire Main.xaml — orchestration only, log bookends (A-7)
Phase 5:  Project-level validation — validate_xaml <project_folder> --lint
Phase 6:  Output Config.xlsx required keys grouped by sheet — validate_xaml --config-keys <project>

If Phase 2 is empty or missing, you are violating the skill rules. Even when no UI inspection is needed (no browser/desktop apps), state that explicitly: Phase 2: no UI inspection required (no browser/desktop apps in scope).

Per-phase reference anchors

Phase	Read before completing
0	scaffolding.md → CRITICAL: Architecture Selection for PDDs (P-2)
1	decomposition.md → Universal Rules 1–8, naming + arguments (Rule 8 = credentials)
2	ui-inspection.md → Playwright MCP workflow + Login Gate (I-2); ui-inspection-reference.md for desktop
2b	cheat-sheet.md → selectors.json schema
2c	scripts/generate_object_repository.py (Lint 94 is ERROR if skipped)
2d	generation.md → Wiring Object Repository References
3	cheat-sheet.md → JSON spec patterns; scripts/generate_workflow.py (Rules G-1, G-2)
3b	scripts/modify_framework.py wire-uielement; decomposition.md § UiElement chain
3c	scripts/modify_framework.py replace-marker SCAFFOLD.DISPATCHER_GET_ITEM (Rule G-3)
4	decomposition.md § Login/Launch + REFramework wiring; A-7 log bookends
5	scripts/validate_xaml <project> --lint
6	scripts/validate_xaml --config-keys <project>; config-sample.md

Config layout rule of thumb

When listing required Config.xlsx keys (Phase 6), apply this rule before falling back to config-sample.md's decision flowchart:

• URLs, API endpoints, file/network paths, shared values across projects, or anything whose value may change frequently → Assets sheet. They are environment-specific, fetched from Orchestrator at InitAllSettings, and admins update them without redeploying. If you expect the value to be tuned post-deployment (timeouts, thresholds, recipient lists, feature flags, batch sizes), it belongs here too — Settings/Constants require a redeploy to change.
• Credential asset NAMES → Settings sheet. The string in the cell is just a name passed to GetRobotCredential; storing it in Assets would trigger a needless GetRobotAsset round-trip. The credential value itself never appears in Config.xlsx — fetch it at point of use.
• Project identity (queue name, process name, processes-to-kill list) → Settings sheet. Local to the project, never changes per environment.
• Framework knobs (retry counts, log message templates) → Constants sheet. Identical across dev/staging/prod.

validate_xaml --config-keys <project> auto-classifies via this rule and emits a per-key reason — review the suggestion before manually editing Config.xlsx.

Compat-v2 (version-band) requirement — ENFORCED: every scaffold_project.py invocation MUST include --band <stable_year> (e.g., --band 25). To pick the band: run python scripts/resolve_nuget.py --all and read the major year of UiPath.System.Activities in the output — that's the latest stable. Available band profiles live under references/version-profiles/UiPath.System.Activities/<year>.<minor>.json. Every dependency MUST be resolved via python scripts/resolve_nuget.py <package> — no version literals from training memory (G-5). If project.json is generated without versionBand, lints 120–122 will REJECT it. The 23.10.x and 24.x bands are end-of-life and MUST NOT be used for new projects in 2026.

Final gate

If you are about to present an architectural plan and have NOT produced a Phase 2: inspection list with one entry per target app (or an explicit "no UI in scope" line), you are violating skill rules — go back and add Phase 2 first.

When To Read Which Reference

Start here. Match the user's task to the right file, then read only what's needed. For files > 200 lines, use grep or line-range reads — never read entire large files or XAML assets.

Common Tasks (check these first)

Task	Read first
Generate a XAML workflow (any kind)	cheat-sheet.md → JSON spec patterns → scripts/generate_workflow.py (G-1)
Scaffold a project	scaffolding.md → Template Selection → run scripts/scaffold_project.py
Plan a new project (PDD → architecture)	scaffolding.md → PLAN SELF-CHECK & Phase 0–6 (READ BEFORE PLANNING)
Inspect a web app (selectors)	ui-inspection.md → Playwright MCP workflow → playwright-selectors.md
Validate XAML	Run scripts/validate_xaml <project> --lint
Fix a specific lint warning	lint-reference.md → search by lint number
Write an expression (VB.NET/C#)	expr-foundations.md (start here for any expression task)
Decomposition / project structure	decomposition.md → Decomposition rules (Universal 1-8, Browser 9-13, Desktop 14)
Fix a user's .xaml file	skill-guide.md → Example 6
Tasks, form tasks	→ uipath-tasks skill (read its SKILL.md)

Activity-Specific Reference

Task	File	Section guidance (for large files)
Pick the right activity for an intent	references/routing-index.md (auto-generated)	Grep for the user's intent or the closest activity name. Don't guess generator names from filenames.
Core activities (Assign, Log, Delay, InputDialog)	xaml-foundations.md (165 lines)	Read in full
Control flow (If, ForEach, While, Flowchart)	xaml-control-flow.md (208 lines)	Read in full
DataTable ops, file system	xaml-data.md (255 lines)	Grep for activity name
Error handling, TryCatch, Throw, RetryScope	xaml-error-handling.md (194 lines)	Read in full
InvokeWorkflowFile, InvokeCode, InvokeMethod	xaml-invoke.md (175 lines)	Read in full
Orchestrator, queues, HTTP, credentials	xaml-orchestrator.md (293 lines)	Grep for activity name
Excel, Email, PDF activities	xaml-integrations.md (285 lines)	Grep: ## Excel, ## Email, or ## PDF
Build/fix selectors	xaml-ui-automation.md (576 lines)	Don't read in full. Grep: ## Selector Reference or specific selector type
UI automation XAML (NClick, NTypeInto, etc.)	xaml-ui-automation.md	Selector guidance only. XAML generation via generate_workflow.py (G-1)

Expression Reference (large files — use targeted reads)

Task	File	Section guidance
DataTable expressions (Select, Compute, LINQ)	expr-datatable.md (432 lines)	Grep: ## Select, ## Compute, ## LINQ, ## Filter
String/DateTime/numeric expressions	expr-strings-datetime.md (502 lines)	Grep: ## String, ## DateTime, ## Numeric, ## Regex
JSON, collections, type conversions	expr-collections-json.md (462 lines)	Grep: ## JSON, ## Dictionary, ## List, ## LINQ

Project & Configuration

Task	Read first
Choose template or variant	scaffolding.md → Choosing the Right Variant
Browser automation with Playwright	ui-inspection.md → Playwright MCP workflow
Desktop app inspection	ui-inspection.md → Desktop Inspection → ui-inspection-reference.md
Login/Launch pattern	decomposition.md → Login/Launch section
Config.xlsx keys and structure	config-sample.md → three-sheet reference, decision flowchart
Extract Config keys from project	Run validate_xaml <project> --lint — lint 39
Lint regression tests	Run scripts/run_lint_tests.py
Ground rules (all rule definitions)	rules.md — single source of truth for G/I/A/P/S rules
project.json schema and configuration fields	scaffolding.md → Key project.json Configuration Fields

Ground Rules

Full rule definitions with rationale: references/rules.md. Rules below are referenced by ID.

1. G-4 — Never generate XAML from scratch. Copy from closest template and modify.
2. G-5 — Never guess NuGet package versions. Run scripts/resolve_nuget.py.
3. G-1 — ⛔ Create .xaml files ONLY via scripts/generate_workflow.py. Never hand-write. See generation.md § Workflow Generation CLI.
4. P-1 — Follow the PDD exactly. Implement the specified approach faithfully — propose alternatives separately.
5. P-2 — Architecture selection: PDD describes BOTH reading AND processing items? → Dispatcher + Performer. See scaffolding.md.
6. A-5 — Modular decomposition. Break into Workflows/<AppName>/ subfolders. See decomposition.md.
7. I-2 — ⛔ HALT at login gates during Playwright inspection. End your response, wait for user.
8. G-3 — ⛔ Framework wiring: GENERATE FIRST, WIRE SECOND. Snippets MUST come from generator output. See scaffolding.md Phase 3c.
9. G-2 — ⛔ JSON specs: WRITE TO DISK, NEVER INLINE. See cheat-sheet.md § type keys for valid types.

CRITICAL: Project Context Check (Always Do This First)

Before generating ANY XAML, determine project context:

A) project.json EXISTS (inside existing project):

• Generate the .xaml file inside the project directory
• Check dependencies — add missing NuGet packages: python3 scripts/resolve_nuget.py --add <project_dir> PackageName

B) project.json DOES NOT EXIST:

• Scaffold first — a standalone .xaml is useless without project.json
• Use scripts/scaffold_project.py (see scaffolding.md)
• Do NOT create the project folder before scaffolding. The script creates <o>/<n>/ automatically. Pre-creating causes duplicate nesting.

Capabilities

1. Generate XAML workflow files — copy from real Studio exports and modify
2. Scaffold UiPath projects — Simple sequence, REFramework Dispatcher, or REFramework Performer
3. Write expressions — VB.NET and C# for UiPath activities (LINQ, DataTable, JSON, DateTime, etc.)
4. Build selectors — strict, fuzzy, dynamic, wildcard, regex selectors for web/desktop/SAP
5. HTTP API integration — OAuth token flows, retry policies, query parameters, response handling
6. Tasks tasks — → Fully decoupled to uipath-tasks skill (generators, lint rules, scaffold hooks all live in uipath-tasks/extensions/, loaded via plugin_loader.py)
7. UI automation — NApplicationCard, NClick, NTypeInto, NSelectItem, NGetText, Extract Table Data, Check App State — via scripts/generate_activities
8. Error handling & workflow — TryCatch, RetryScope, Throw/Rethrow, InvokeWorkflowFile, AddQueueItem, GetRobotCredential, BuildDataTable, IfElseIfV2, MultipleAssign — via scripts/generate_activities
9. File system operations — Copy/Move/Delete files, Create Directory, Path Exists
10. Invoke Code/Method — inline C#/VB.NET code blocks, instance/static method calls

Reference Files

File	Coverage
references/xaml-foundations.md	XAML file structure, namespace declarations, core activities (Assign, Log, InputDialog, MessageBox, Delay), variable & argument declarations
references/xaml-control-flow.md	If, IfElseIf, ForEach, ForEachRow, While, DoWhile, Break/Continue, ForEachFile, Flowchart, State Machine, annotations
references/xaml-data.md	BuildDataTable, AddDataRow, FilterDataTable, MergeDataTable, SortDataTable, OutputDataTable, JoinDataTables, LookupDataTable, DeserializeJSON, file system ops
references/xaml-error-handling.md	TryCatch, Throw/Rethrow, exception types, RetryScope (incl. NCheckState condition)
references/xaml-invoke.md	InvokeWorkflowFile, InvokeCode, InvokeMethod
references/xaml-orchestrator.md	GetRobotAsset, GetRobotCredential, AddQueueItem, GetQueueItem, SetTransactionStatus, HTTP Request. Tasks → uipath-tasks skill
references/xaml-integrations.md	Excel Classic Workbook (ReadRange, WriteRange, WriteCell), Email/Integration Service (GetIMAP, SendMail), PDF (ReadPDFText, ReadPDFWithOCR)
references/xaml-ui-automation.md	Selector construction, dynamic selectors, fuzzy/regex, anchor targeting, desktop frameworks, Version table. For XAML generation use generators — this file is for selector guidance and activity property reference. Large file — use grep or line-range reads.
references/expr-foundations.md	VB.NET + C# expression syntax, null safety patterns. Read first for any expression task
references/expr-datatable.md	DataTable operations: Select, Compute, filter, sort, lookup, merge, clone, column ops, row iteration. Large file — grep for section.
references/expr-strings-datetime.md	String (split, join, trim, replace, format), DateTime (parse, format, diff, business days), file/path, numeric, regex. Large file — grep for section.
references/expr-collections-json.md	Array/List, Dictionary, JSON (JObject, JArray, parse, query, build), LINQ on typed collections, type conversions, Queue Item. Large file — grep for section.
references/routing-index.md	Activity selection index — auto-generated from references/annotations/*.json. Maps user intent → generator with description + use_when per activity, plus a "don't auto-generate" section listing wizard-only activities. Consult this BEFORE guessing a generator name. Regenerate with uipath-core/scripts/generate_routing_index.py.
references/golden-templates.md	Template catalog — patterns extracted from each real template file
references/scaffolding.md	Template selection, NuGet mapping, XAML validation, project scaffolding (variants, dispatcher/performer, transaction types), full project generation checklist
references/decomposition.md	Naming conventions, decomposition rules (universal 1-8, browser 9-13, desktop 14), common process patterns, argument design, Login/Launch pattern, REFramework Init/Close, UiElement chain
references/generation.md	Object Repository, Workflow Generation CLI (JSON spec format, 104 core generators + plugin extensions), Activity Generators (usage pattern, what model provides vs what generators lock down)
references/ui-inspection.md	Playwright MCP workflow (login gate, 5-step process, element mapping), Desktop inspection (PowerShell, inspect-ui-tree.ps1, framework detection)
references/skill-guide.md	Index + examples. Routes to scaffolding/decomposition/generation/ui-inspection. Contains 7 worked examples + anti-example
references/lint-reference.md	85 lint rules by severity, searchable by lint number (core rules; plugins add more — uipath-tasks registers AC-26..AC-34)
references/playwright-selectors.md	Playwright MCP → UiPath selector mapping
references/config-sample.md	Config.xlsx three-sheet reference (Settings, Constants, Assets), key naming conventions, sheet placement decision flowchart, required keys output format
references/cheat-sheet.md	JSON spec patterns (multiple_assign, if, try_catch, foreach_row, pick_login_validation, filter_data_table, add_queue_item, selectors.json), modify_framework.py CLI+Python API, valid enum values, naming, quick rules
references/cheat-sheet.md § Desktop Form-Filling	Desktop form-filling: tab nav, idx selectors, save verification, data externalization
references/ui-inspection-reference.md	inspect-ui-tree.ps1 reference — UIA→UiPath property mapping, framework detection, WinForms
references/rules.md	Ground Rules Reference — single source of truth for all generation (G), inspection (I), architecture (A), PDD (P), SAP (S), and skill authoring (K) rules. Other docs reference by ID

Scripts

All scripts/ paths below are relative to this skill's directory (.claude/skills/uipath-core/). Invoke from the skill root: cd .claude/skills/uipath-core && python3 scripts/<script>.py ...

File	Purpose
scripts/validate_xaml	Validate generated XAML — structural checks + lint rules (core + plugin). Use --golden for asset templates. See lint-reference.md for full rule table.
scripts/resolve_nuget.py	Resolve real NuGet versions. Query UiPath feed for latest stable. Validate project.json. Add/update deps in existing project.json (--add).
scripts/scaffold_project.py	Scaffold UiPath projects (sequence / dispatcher / performer). Customizes Config.xlsx. Dispatcher replaces GetQueueItem with DataTable row indexing.
scripts/config_xlsx_manager.py	Add/list/validate Config.xlsx keys. Cross-references XAML Config() refs vs actual sheets.
scripts/modify_framework.py	Insert InvokeWorkflowFile into framework files, replace SCAFFOLD.* markers, wire UiElement argument chain (wire-uielement), add variables with auto type normalization (add-variables), replace placeholder expressions (set-expression). ⛔ G-8: Never Edit/Write .xaml directly — use this script or generate_workflow.py.
scripts/generate_activities	Deterministic XAML generators for 95 core activities. Locks down enums, versions, child elements. MANDATORY for NTypeInto, NClick, NGetText, NCheckState, NApplicationCard, etc. Plugin skills add more (e.g., Tasks, SAP WinGUI).
scripts/generate_workflow.py	Generate complete .xaml files from JSON specs. 104 core generators + plugin generators loaded via plugin_loader.py. Covers ALL activities including Pick login validation, TryCatch, ForEachRow, NExtractData, NCheckState. Pass --project-dir <project> to auto-wire Object Repository references (Reference=/ContentHash= on TargetAnchorable) from .objects/refs.json. ⛔ Do NOT write .xaml by hand — use this CLI instead.
scripts/generate_object_repository.py	Generate Object Repository (.objects/ tree). CLI: python3 generate_object_repository.py --from-selectors selectors.json --project-dir <dir>. Reads selectors.json (written during Playwright inspection) with full app/screen/element hierarchy. Lint 94 is ERROR — project cannot pass validation without populated Object Repository.
scripts/inspect-ui-tree.ps1	Windows-only. Inspect desktop app UI tree via UIA API. Run via Bash (powershell -File).
scripts/regression_test.py	Regression tests — validates templates, scaffolding, naming conventions, line count accuracy, skill integrity
scripts/run_lint_tests.py	Lint regression: verifies bad XAML test cases trigger expected lints. Run after modifying lint rules.

Battle-test scripts (manual-only)

scripts/battle_test_studio.py and scripts/battle_test_activities.py are NOT run by CI and have side-effects: they shell out to uip rpa create-project, scaffold real UiPath Studio Desktop projects under the system temp dir, and invoke Studio via IPC. Run them manually after generator changes (to confirm Studio still accepts the produced XAML) and before cutting a release. Requirements: UiPath Studio Desktop installed locally, @uipath/cli (npm i -g @uipath/cli) on PATH, and a free Studio editor process available for IPC. Pair with scripts/grade_battle_test.py to score the resulting projects.

Key Architecture Rules

Full definitions: references/rules.md § Architecture Rules (A-1 through A-12).

App initialization (A-1): ALL apps open and ready by end of InitAllApplications.xaml. Action workflows ONLY attach (OpenMode="Never"). Wire UiElement chain: python3 scripts/modify_framework.py wire-uielement <project> <AppName>.

Key constraints: no flat files in Workflows/ (must be in app subfolders), login stays inside AppName_Launch.xaml (no separate AppName_Login.xaml), navigation uses shared Utils/Browser_NavigateToUrl.xaml (A-6), persistence activities stay in Main.xaml (A-2), SetTransactionStatus.xaml never modified (A-4), dispatchers pass Nothing for in_TransactionItem.

Login/Launch Workflow Pattern

See decomposition.md → "Login/Launch Workflow Pattern" for the full recipe, required XAML structure, argument design, UiElement reference chain, and common mistakes. Key rule: login stays inside AppName_Launch.xaml — NEVER create a separate AppName_Login.xaml. Copy structure from golden sample WebAppName_Launch.xaml.

Quick Validation Reference

For detailed lint rules by number, see lint-reference.md. The most critical categories: