Execution Styles

Nash tasks support three execution styles. Each task must use exactly one style.

Command Style

The command field passes a single string to the system shell for interpretation. Shell features like pipes, redirects, globbing, and variable expansion are all available.

[[task]]
id = "serve"
title = "Start Dev Server"
command = "npm run dev -- --port 3000"

A shell override can be used to force a specific shell regardless of the platform default:

[[task]]
id = "deploy"
title = "Deploy"
shell = ["bash", "-c"]
command = "deploy.sh --env production"

Argv Style

The argv field passes an argument vector directly to the executable without shell interpretation. No globbing, no variable expansion, no piping — the process receives exactly the tokens you specify.

[[task]]
id = "lint"
title = "Lint Project"
argv = ["cargo", "clippy", "--", "-D", "warnings"]

This is ideal when arguments contain spaces, special characters, or when you want deterministic behavior across platforms without quoting concerns.

Multi-Step Execution

Tasks with [[task.step]] entries run a sequence of commands in order. If any step fails, execution stops and the task is marked as failed.

[[task]]
id = "quality-gates"
title = "Quality Gates"
target = "new_tab"

[[task.step]]
name = "Format Check"
command = "cargo fmt --check"

[[task.step]]
name = "Lint"
command = "cargo clippy -- -D warnings"

[[task.step]]
name = "Tests"
argv = ["cargo", "test"]

Step-Level Overrides

Each step can override task-level settings:

Field	Type	Description
name	string	Human-readable step name (shown in progress output)
cwd	string / path	Step-local working directory
env	table	Step-local environment variables (merged with task)
shell	array of strings	Step-local shell argv prefix
command	string	Shell command for this step
argv	array of strings	Argv-style execution for this step

[[task]]
id = "build-and-test"
title = "Build & Test"
env = { NODE_ENV = "production" }

[[task.step]]
name = "Frontend Build"
cwd = "./frontend"
command = "npm run build"

[[task.step]]
name = "Backend Tests"
cwd = "./backend"
env = { TEST_DB = "sqlite" }
command = "pytest"

Note: Step cwd and env are composed into generated scripts in declaration order. Earlier steps' env vars are inherited by later steps within the same task.

Continue to Targets & Execution Domains to control where your tasks run.