fit-codegen

name	fit-codegen
description	Generate JavaScript types, service base classes, typed clients, gRPC definitions, and MCP field metadata from proto contracts, or download a pre-generated bundle. Use when a proto definition changed and the generated code must be regenerated to match, when setting up a gRPC product for the first time, or when a runtime image needs to fetch the generated bundle.

Generate Code from Proto Definitions

fit-codegen reads the shared proto contracts and emits the generated code that keeps JavaScript types, service endpoints, and MCP tools in sync with a single source of truth. Every generated file carries a @generated by fit-codegen header — do not edit generated files; change the proto and regenerate. Two subcommands: generate produces the code, and download fetches a pre-generated bundle for a runtime that does not build.

When to Use

• Regenerate everything after a proto change — fit-codegen generate --all
• Generate one artifact kind — --type, --service, --client, --definition, --metadata
• Bootstrap a gRPC product for the first time
• Fetch the generated bundle at container startup — fit-codegen download

Usage

# Generate all artifacts
fit-codegen generate --all

# Generate a single kind
fit-codegen generate --type        # JavaScript types only
fit-codegen generate --service     # Service base classes only
fit-codegen generate --client      # Typed clients only
fit-codegen generate --definition  # gRPC definitions only
fit-codegen generate --metadata    # Field metadata for MCP only

# Download and unpack the generated bundle, then optionally exec a command
fit-codegen download
fit-codegen download -- <command>

Combine flags to generate a subset: fit-codegen generate --type --client generates types and clients only. generate needs the proto-compiler toolchain, which ships with a default install; download is lean and carries none of it.

Documentation

• Keep Types Synced with Proto Definitions — One source of truth from proto definition to runtime: types, MCP tools, and service endpoints regenerated with fit-codegen.