gRPC Generation

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Scaffold a complete [[grpc_routes]] config and synthetic stub files from a .proto file in one command.

Usage

apitwin generate --proto geo.proto --out ./mocks

# Multiple proto files
apitwin generate --proto countries.proto --proto cities.proto --out ./mocks

# With extra import paths for proto imports
apitwin generate --proto geo.proto --import-path ./vendor/protos --format yaml

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Generated output

For a CountryService with three methods:

mocks/
├── apitwin.toml            # [[grpc_routes]] for all methods
└── stubs/
    ├── CountryService_GetCountry.json
    ├── CountryService_ListCountries.json
    └── CountryService_CreateCountry.json

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Stub synthesis

Stubs are synthesised from the output message descriptor — field names, types, and common naming patterns produce sensible placeholder values:

Field name pattern	Synthesised value
contains id	"{{uuid}}"
contains email	"user@example.com"
contains url / uri	"https://example.com"
contains time / at / date	"{{now}}"
contains name	"Example Name"
bool type	true
int32 / int64 etc.	1
float / double	1.0

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Flags

Flag	Default	Description
--proto <file>	—	Path to a .proto file; repeat for multiple files
--import-path <dir>	—	Extra directory for proto imports; repeat for multiple
--out <dir>	mocks	Output directory
--format <fmt>	toml	Config format: toml, yaml, json

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Serve immediately

After generating, start the server:

apitwin --config ./mocks --grpc-proto geo.proto

If your protos import shared types from another directory, use --import-path on both commands:

apitwin generate --proto proto/service/v1/service.proto --import-path proto/ --out ./mocks
apitwin --config ./mocks --grpc-proto proto/service/v1/service.proto --import-path proto/

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See also: gRPC Quick Start | Configuration | OpenAPI Generation