Project Configuration

Every Achronyme project can have an achronyme.toml file at its root. This file configures defaults for CLI commands, eliminating the need to pass flags repeatedly.

Quick start

ach init my-circuit
cd my-circuit
ach run              # reads entry from achronyme.toml

Config resolution

The CLI searches for achronyme.toml by walking up from the input file’s directory (or the current working directory if no file is specified). The first match is used.

Values are resolved with this precedence:

CLI flags (explicit)  >  achronyme.toml  >  hardcoded defaults

Use --no-config to disable achronyme.toml loading entirely.

Full schema

[project] — Project metadata

[project]
name = "my-circuit"           # Required. Must match [a-zA-Z_][a-zA-Z0-9_-]*
version = "0.1.0"             # Required. Semantic versioning (MAJOR.MINOR.PATCH)
description = "A ZK circuit"  # Optional
license = "MIT"               # Optional. SPDX identifier
authors = ["Alice <[email protected]>"] # Optional
entry = "src/main.ach"        # Optional. Default entry file for run/compile/circuit/disassemble

When entry is set, you can omit the file path from CLI commands:

# Instead of:
ach run src/main.ach

# Just:
ach run

[build] — Compilation settings

[build]
backend = "r1cs"          # "r1cs" (default) or "plonkish"
optimize = true           # Enable IR optimization passes (default: true)
error_format = "human"    # "human" (default), "json", or "short"

Field	CLI equivalent	Default
backend	--backend, --prove-backend	"r1cs"
optimize	--no-optimize (inverted)	true
error_format	--error-format	"human"

[build.output] — Output paths

[build.output]
r1cs = "build/circuit.r1cs"      # Default .r1cs output path
wtns = "build/witness.wtns"      # Default .wtns output path
binary = "build/{name}.achb"     # Default .achb output path ({name} = project.name)
solidity = ""                    # If non-empty, generate Solidity verifier
plonkish_json = ""               # If non-empty, export Plonkish JSON

The {name} template variable is replaced with project.name.

[vm] — Virtual machine settings

[vm]
max_heap = "256M"     # Maximum heap size (e.g., "256M", "1G", "512K"). Empty = unlimited
stress_gc = false     # Force GC on every allocation (default: false)
gc_stats = false      # Print GC statistics after execution (default: false)

Field	CLI equivalent	Default
max_heap	--max-heap	unlimited
stress_gc	--stress-gc	false
gc_stats	--gc-stats	false

[circuit] — Circuit input declarations

[circuit]
public = ["x", "y"]      # Public input variable names
witness = ["secret"]      # Witness input variable names

These are equivalent to --public x,y --witness secret on the command line. If --public or --witness are explicitly passed on the CLI, they override these values.

If both the CLI flags and TOML fields are empty, the compiler uses in-source public and witness declarations.

Minimal example

[project]
name = "multiply"
version = "0.1.0"

[build]
backend = "r1cs"

Full example

[project]
name = "merkle-prover"
version = "0.2.0"
description = "Merkle tree membership proof circuit"
license = "MIT"
entry = "src/main.ach"

[build]
backend = "r1cs"
optimize = true
error_format = "human"

[build.output]
r1cs = "build/circuit.r1cs"
wtns = "build/witness.wtns"
solidity = "build/Verifier.sol"

[vm]
max_heap = "512M"

Validation

The CLI validates the TOML file on load:

• project.name must match [a-zA-Z_][a-zA-Z0-9_-]*
• project.version must be valid semver (MAJOR.MINOR.PATCH)
• build.backend must be "r1cs" or "plonkish"
• build.error_format must be "human", "json", or "short"
• vm.max_heap must be a valid size string if non-empty
• circuit.public / circuit.witness entries must be valid identifiers
• project.entry must end in .ach or .achb
• Unknown fields are rejected (forward compatibility via explicit sections)