programmatic llm invocation with template literals
Executes LLM queries using JavaScript template literal syntax (backtick-delimited prompts with $` markers) embedded directly in GenAIScript files. The runtime parses these template expressions, sends them to configured LLM providers (OpenAI, Anthropic, or local models), and returns structured or unstructured responses that can be assigned to variables for downstream processing. This approach enables prompt composition as first-class JavaScript expressions rather than string concatenation.
Unique: Uses JavaScript template literal syntax ($`...`) as the primary interface for LLM calls, embedding prompts as first-class language constructs rather than string APIs. This allows IDE autocomplete, syntax highlighting, and variable interpolation without additional abstraction layers.
vs alternatives: More ergonomic than REST API calls or string-based prompt builders because prompts are native JavaScript expressions with full IDE support and variable scoping.
multi-format file ingestion and parsing
Automatically extracts and parses content from diverse file formats (PDF, DOCX, CSV, plain text) using specialized parsers accessible via the `parsers.*` API. Files are matched using glob patterns or explicit file arrays, parsed into structured or text representations, and made available to LLM prompts via the `env.files` context. The runtime handles encoding detection, format-specific extraction (e.g., PDF text layers, DOCX metadata), and error handling for malformed files.
Unique: Provides a unified `parsers.*` API for heterogeneous file formats, abstracting format-specific parsing logic behind a consistent interface. This eliminates the need to write custom parsing code for each file type or call external services.
vs alternatives: More integrated than calling separate parsing libraries or cloud APIs because parsing happens locally within the script runtime, reducing latency and avoiding data egress.
script execution with file context and filtering
Executes scripts with automatic file discovery and filtering based on glob patterns or explicit file lists. The runtime matches files against patterns, loads their content, and makes them available to the script via `env.files`. This enables batch processing of files with consistent logic without manual file enumeration.
Unique: Integrates file discovery and filtering directly into the script runtime, eliminating the need to write separate file enumeration logic. Matched files are automatically available as script variables.
vs alternatives: More convenient than manual file enumeration because glob patterns are evaluated by the runtime, and file content is automatically loaded and made available to prompts.
output formatting and result serialization
Formats script execution results for display or export, supporting multiple output formats (plain text, JSON, structured logs). Results can be written to stdout, files, or returned as structured data for downstream processing. The runtime handles serialization of complex data types and provides options for formatting output for human readability or machine parsing.
Unique: Provides built-in result formatting and serialization as part of the script runtime, eliminating the need to manually format or serialize results before output.
vs alternatives: More integrated than manual result formatting because the runtime handles serialization and provides options for different output formats without additional code.
schema-based data extraction and validation
Defines JSON schemas (using JSON Schema or Zod syntax) to validate and repair LLM-generated outputs. The runtime enforces schema constraints, attempts to repair malformed data (e.g., fixing JSON syntax errors or missing fields), and provides structured output that matches the schema definition. Schemas are defined inline in scripts using `defSchema()` and can be referenced in prompts to guide LLM output format.
Unique: Combines schema definition, LLM-guided extraction, and automatic repair in a single workflow. Rather than validating post-hoc, schemas are passed to the LLM to guide output format, and repair logic attempts to fix common errors before validation fails.
vs alternatives: More robust than raw LLM output parsing because it enforces schema compliance and repairs common formatting errors, reducing downstream pipeline failures compared to manual JSON parsing.
semantic vector search across project files
Performs semantic similarity search across project files using embeddings and vector retrieval. The `retrieval.vectorSearch()` API accepts a query string, embeds it using a configured embedding model, and returns the most similar files or file chunks ranked by cosine similarity. This enables context-aware file selection for LLM prompts without explicit file enumeration, supporting use cases like 'find similar code' or 'retrieve relevant documentation'.
Unique: Integrates semantic search directly into the scripting runtime, allowing queries to be composed programmatically and results to be piped into LLM prompts without external API calls or separate indexing steps.
vs alternatives: More efficient than full-text search for semantic queries and more integrated than external RAG services because search results are available as script variables without context switching.
nested prompt composition and multi-stage workflows
Enables prompts to invoke other prompts via the `runPrompt()` function, allowing multi-stage LLM workflows where outputs from one prompt feed into subsequent prompts. Each nested prompt has its own context (files, variables, schema), and results are returned as structured data that can be processed or passed to downstream prompts. This pattern supports complex reasoning chains, iterative refinement, and modular prompt reuse.
Unique: Treats prompts as first-class composable functions within a scripting language, allowing complex workflows to be expressed as JavaScript code with full control flow (loops, conditionals, error handling) rather than static workflow definitions.
vs alternatives: More flexible than linear prompt chains because nested prompts can be conditionally executed, looped, or composed based on runtime data, enabling adaptive workflows that respond to intermediate results.
cli-based batch script execution
Executes GenAIScript scripts from the command line using `npx genaiscript run`, enabling automation outside VS Code and integration with CI/CD pipelines, cron jobs, or shell scripts. The CLI accepts script paths, environment variables, and input parameters, executes the script in a headless runtime, and outputs results to stdout or files. This decouples script development (in VS Code) from script execution (in automation contexts).
Unique: Provides a dual-mode execution model where scripts are developed interactively in VS Code but executed headlessly via CLI, enabling the same script to be used for both prototyping and production automation.
vs alternatives: More portable than VS Code-only execution because scripts can run in any environment with Node.js, enabling integration with CI/CD systems, containers, and serverless platforms without requiring VS Code.
+4 more capabilities