@neural-ng/mcp-server

Read-only Angular UI expert interface for NeuralNg component discovery, contract-backed composition, usage validation, project-consistent guidance and compact theme workflows.

The server is separate from @neural-ng/core. Angular applications never load an MCP runtime in the browser. Theme tools return recipes, validation results, diffs and compile summaries; they do not write files or execute shell commands.

Run

npx -y @neural-ng/mcp-server

Generic MCP client configuration:

{
  "command": "npx",
  "args": ["-y", "@neural-ng/mcp-server"]
}

The process uses stdio. Standard output is reserved for MCP JSON-RPC messages; fatal diagnostics are written to standard error.

Resources

Agent capability discovery:

• neural://server/capabilities — versioned tool groups, result schemas, inspection limits, safety guarantees and compatibility guidance

Component and package resources:

• neural://catalog
• neural://package/exports
• neural://components/{id}/contract
• neural://components/{id}/readme
• neural://components/{id}/llms

Icon resources:

• neural://icons/catalog — compact package totals, categories, versions and brand-search policy; use search_icons for bounded matches

Theme resources:

• neural://themes/catalog
• neural://themes/schema
• neural://themes/presets
• neural://themes/presets/neutral
• neural://themes/presets/glass
• neural://themes/presets/mist
• neural://themes/presets/futuristic
• neural://themes/ai-guide

Component resources are registered as fixed URIs. The server does not accept a filesystem path and does not read arbitrary files.

Component tools

search_components

Searches public selectors, entry points, summaries, README files and llms.txt guidance.

{
  "query": "date calendar localized",
  "limit": 5
}

get_component

Returns the schema-versioned Angular API contract used by coding agents. The standard detail level includes Signal inputs, models and outputs, typed template contexts, required providers, class contract names and the available example count without sending full documentation through the context window.

{
  "component": "neural-select",
  "detail": "standard"
}

Use detail: "summary" during discovery and detail: "full" only when every class slot and embedded example is required. Results are returned as both MCP text content and structuredContent.

get_component_examples

Returns a bounded list of published examples with their documentation heading, language and code.

{
  "component": "neural-table",
  "limit": 3
}

get_component_contract

Legacy full-contract lookup retained for existing clients. New integrations should use get_component so they can select a token-efficient detail level.

{
  "component": "neural-tri-state-checkbox"
}

recommend_components

Uses deterministic intent matching. It does not invoke another model or a network service.

{
  "goal": "nullable inherited permission checkbox",
  "limit": 3
}

Icon intelligence

search_icons

Searches all 6,184 outline and filled Neural Icons variants by exact name, category, or common UI intent. Results are bounded and include the exact nt class, the smallest valid CSS import, ready-to-use markup, supported effects, and accessibility guidance. Brand icons are excluded by default.

{
  "query": "delete user",
  "style": "outline",
  "limit": 10,
  "include_brands": false
}

Use style: "filled" only when the returned icon lists filled support. Pass a category to narrow the deterministic search. Set include_brands: true only when the product explicitly needs a trademarked brand glyph.

Composition intelligence

plan_ui

Turns a product requirement into a contract-backed NeuralNg composition. The result contains selected primitives and reasons, exact standalone imports, provider requirements, structural regions, state ownership, accessibility checks, implementation order, and component ids that can be passed directly to get_component_examples.

{
  "goal": "Admin user management with search, role filter, table and detail drawer",
  "kind": "auto"
}

kind accepts auto, form, page, or table. Auto detection is deterministic; it does not call another model or network service.

Structure-specific planners

Use suggest_form_structure, suggest_page_structure, or suggest_table_structure when the outer interaction shape is already known. Each accepts a non-empty goal and returns the same versioned plan contract as plan_ui with the corresponding kind fixed.

Contract correctness

validate_usage

Parses an Angular template with @angular/compiler and checks the resulting AST against the generated NeuralNg public contracts. It understands Angular control flow, structural directives, interpolation, property/event/two-way bindings, custom elements, and NeuralNg attribute selectors on native elements. It reports stable diagnostic codes with source positions for Angular syntax errors, unknown selectors or bindings, missing required inputs, invalid literal unions (including exported type aliases), inaccessible icon-only buttons, missing standalone imports, required providers, and duplicate Toast channels.

Explicit ng-template directives (such as neuralTableCell) and their nested components are checked too. Event listeners do not satisfy required inputs; model outputs use their generated Change suffix. String-literal property bindings are checked against input unions, and empty static or string-literal accessible labels do not satisfy the icon-only button check.

This is a template contract checker, not a full Angular application compiler. Dynamic expression types, runtime label values, template context types, and application behavior still require Angular compilation and application tests.

{
  "template": "<neural-button icon=\"trash\"></neural-button>",
  "imports_json": "[\"NeuralButton\"]",
  "providers_json": "[]"
}

The schema-v2 result includes valid, parser identity and version, syntax status, diagnostics, exact suggested imports grouped by entry point, and provider requirements. NNG000 identifies Angular parse failures before contract validation. Informational missing-import diagnostics do not make a template invalid; error diagnostics do.

Project-aware tools

inspect_project

Inspects the Angular workspace used as the MCP process working directory and returns declared Angular/NeuralNg package versions, workspace kind, summary counts, used selectors and occurrence locations, icon classes and stylesheets, imports grouped by entry point, configured providers, theme and Appearance setup, inferred conventions, and actionable diagnostics. External templates, inline component templates and attribute directives are parsed with @angular/compiler; invented APIs and accessibility failures therefore use the same diagnostics as validate_usage.

The scan is read-only and accepts no filesystem path. It skips dependencies, build output, VCS data, tests, declarations, and symlinks. Work is bounded to 400 source files, 256 KiB per file, 5 MiB in total, and 10,000 directory entries; oversized files are rejected before their contents are read. The result explicitly reports truncation and analysis confidence. Absolute paths are not returned, and component/icon evidence is capped at 25 relative paths per item while filesOmitted preserves the omitted count. angularVersion and neuralPackages contain declarations from the workspace package.json. Optional installedCoreVersion and installedAngularVersion separately report exact versions read from the corresponding local node_modules package manifests. Only bounded metadata within the workspace is read, not dependency source code. Core compatibility prefers installed metadata when available; dependency ranges without that evidence require review. Independently released Core, Icons, Theme, and MCP packages are not required to share a version. Diagnostics validate selectors and APIs present in the generated MCP catalog; an unknown selector from a separate package remains visible instead of being silently treated as valid.

inspect_neuralng_project remains as a compatibility alias and returns the same schema-v2 result. New agents should call inspect_project.

suggest_consistent_ui

Combines inspect_project with the composition engine. It identifies which planned primitives already have a project convention, which ones are new, and how to preserve the detected theme, unstyled ownership, and import style. The schema-v2 result includes per-component relative-path evidence, exact import reuse/add partitions, required-provider deltas, declared Core versus catalog version alignment, bounded project risks, and explicit next calls to get_component_examples and validate_usage. It returns focused project context rather than duplicating the full inspect_project result.

{
  "goal": "Add a searchable project table with a detail drawer",
  "kind": "table"
}

Compact theme tools

The theme workflow intentionally operates on the small recipe rather than the resolved 1,348-token Core and Editor graph.

create_theme_recipe

{
  "name": "violet-workspace",
  "options_json": "{\"preset\":\"glass\",\"primary\":\"#7c3aed\",\"radius\":\"large\"}"
}

validate_theme_recipe

{
  "recipe_json": "{\"schemaVersion\":1,\"name\":\"violet-workspace\",\"extends\":\"neutral\"}"
}

edit_theme_recipe

Applies a bounded, prototype-safe sparse patch and validates the result. Theme validation rejects declaration injection, external CSS URLs, malformed aliases, and unknown component tokens before compilation.

{
  "recipe_json": "{\"schemaVersion\":1,\"name\":\"violet-workspace\",\"extends\":\"neutral\"}",
  "patch_json": "{\"set\":{\"color.primary\":\"#7c3aed\",\"shape.radius\":\"large\"}}"
}

diff_theme_recipes

Returns only changed dotted recipe paths instead of repeating both recipes.

get_component_theme_contract

Returns one component's supported theme properties. Use detail: "names" by default and request detail: "defaults" only when current mode values are needed.

{
  "component": "toast",
  "detail": "names"
}

Recipe versions and quality metadata

Theme MCP tools author schema version 1. Early preview recipes should first be migrated with neural-theme migrate or migrateThemeRecipe() from @neural-ng/theme; MCP remains read-only and does not rewrite user files. Preset resources include stability and quality governance metadata so agents can prefer release baselines unless the user explicitly requests a preview style.

compile_theme_recipe

Runs the real @neural-ng/theme compiler and returns validation diagnostics, summary data, artifact byte sizes and integration instructions. It deliberately does not send full CSS or token artifacts through the model context. Generate those files with:

npx neural-theme build

Catalog source

The committed component catalog is generated from:

• tsconfig.base.json public @neural-ng/core/* paths;
• each public secondary entry point's index.ts;
• public Angular component and directive selectors;
• package exports, README files and llms.txt files.

Regenerate and verify it with:

npx nx run neural-mcp:catalog
npx nx run neural-mcp:catalog-check

Quality commands

npx nx lint neural-mcp
npx nx test neural-mcp
npm run mcp:eval
npx nx build neural-mcp
npx nx run neural-mcp:package-test
npx nx run neural-mcp:mcp-smoke

mcp:eval reads the versioned manifest in evals/manifest.json. It gates ten composition regressions and the beta-exit existing-project user-management scenario across inspection, consistency planning, exact contracts, valid template acceptance, accessibility, provider requirements, and invented API rejection. CI runs it independently from the ordinary unit suite.

mcp-smoke packs both @neural-ng/theme and the MCP server, installs them into an isolated temporary consumer, initializes stdio MCP, reads component and theme resources, then calls component discovery and compact theme compiler tools.