Project Configuration

Seen projects use Seen.toml for configuration.

Minimal Seen.toml

[project]
name = "my_project"
version = "0.1.0"
language = "en"

Project Structure

my_project/
├── Seen.toml
├── src/
│   └── main.seen
├── tests/
│   └── test_main.seen
└── benchmarks/
    └── bench_main.seen

[project] Section

Field	Type	Required	Description
`name`	String	Yes	Project name
`version`	String	Yes	Semantic version (e.g., `"1.0.0"`)
`language`	String	No	Keyword language: `en`, `ar`, `es`, `ru`, `zh`, `ja` (default: `en`)
`visibility`	String	No	Visibility model: `"caps"` (capability-based)
`description`	String	No	Project description
`authors`	Array	No	List of author names
`edition`	String	No	Language edition (e.g., `"2025"`)
`modules`	Array	No	Explicit module list

Example:

[project]
name = "seen_compiler"
version = "1.0.0"
language = "en"
visibility = "caps"
description = "Self-hosted Seen compiler"
authors = ["Seen Language Team"]
edition = "2025"
modules = [
    "src/bootstrap",
    "src/lexer",
    "src/parser",
    "src/typechecker",
    "src/main.seen",
]

[dependencies] Section

[registries]
default = "https://seen.yousef.codes/packages"

[dependencies]
mathx = "0.1.0"
gamekit = { path = "../gamekit" }

Package dependencies can be either:

exact registry versions like "0.1.0"
local Seen package paths like { path = "../gamekit" }

Dependencies are imported by the dependency key:

import mathx.value.{answer}
import gamekit.player.{Player}

Registry packages are installed under .seen/packages/, and registry-backed projects get a Seen.lock recording the resolved package versions and install paths.

[native.dependencies] Section

[native.dependencies]
sdl3 = { path = "native/lib" }
vulkan = {}

[native.dependencies] controls linker-facing native libraries. For project-local native libraries, add path = "..." to point at the directory containing the library file. The path is resolved relative to the nearest Seen.toml. Seen adds -L<resolved-path> during linking, and on native Linux/macOS builds it also records that directory as a runtime search path so the output can run without extra LIBRARY_PATH or LD_LIBRARY_PATH wrappers.

Legacy system = true entries inside [dependencies] are still accepted for backward compatibility, but new manifests should prefer [native.dependencies].

[build] Section

[build]
targets = ["native", "wasm32", "riscv64"]
optimize = "speed"      # "speed" or "size"
lto = true              # Link-time optimization
codegen-units = 1       # Single unit for best optimization
debug-info = true       # Include debug symbols
profile = "release"     # "release" or "debug"

[targets.*] Section

Per-target configuration:

[targets.native]
triple = "x86_64-unknown-linux-gnu"
features = ["simd", "vectorization"]

[targets.riscv64]
triple = "riscv64-unknown-linux-gnu"
features = ["rvv", "compressed", "atomic"]

[targets.wasm32]
triple = "wasm32-unknown-unknown"
features = ["simd128"]

[format] Section

Code formatting preferences:

[format]
line-width = 100
indent = 4
trailing-comma = true
document-types = [".seen", ".md", ".toml"]

[test] Section

[test]
threads = "auto"    # number of test threads
timeout = 300       # seconds per test
coverage = true     # enable code coverage

[benchmark] Section

[benchmark]
iterations = 1000
warmup = 100
timeout = 60
statistical-significance = 0.05

[lsp] Section

Language server features:

[lsp]
diagnostics = true
completion = true
hover = true
goto-definition = true
find-references = true
semantic-tokens = true

[performance] Section

Performance targets (informational):

[performance]
lexer-throughput = "25M tokens/sec"
parser-throughput = "800K lines/sec"
typechecker-speed = "80μs/function"
codegen-speed = "300μs/function"
memory-overhead = "10%"

Getting Started -- project setup
Packaging -- package registries and publishing
CLI Reference -- build commands