Managed mode and monorepos

Managed mode

Managed mode fills in language metadata your .proto files omit, so you can keep them free of Go-specific options. It runs after parsing and before generation.

Given a proto with no option go_package:

package greeter.v1;   // no go_package

pass a module prefix, and protogen synthesizes one:

protogenall --proto_path=proto --go-package-prefix=example.com/gen --out=gen proto

The rule is <prefix>/<dir>;<name>, where <dir> is the proto's path relative to its import root and <name> is derived from the proto package (a trailing version segment like v1 is skipped in favor of the segment before it — so greeter.v1 → package greeter).

You can also override an empty package declaration:

protogenall --proto-package=greeter.v1 ...

This mirrors buf's "managed mode": metadata lives outside the proto, supplied at generation time.

Batch generation

Inputs may be files, directories, or globs. A directory is walked recursively for *.proto, and each file is mapped to its import-relative name. Output mirrors the source tree.

# generate the whole tree in one call
protogenall --proto_path=monorepo --go-package-prefix=example.com/gen --out=gen monorepo

# or a glob
protogenall --proto_path=monorepo --go-package-prefix=example.com/gen --out=gen "monorepo/users/v1/*.proto"

For a layout like:

monorepo/
  common/money.proto        package common;
  orders/v1/order.proto      package orders.v1;   imports common/money.proto
  users/v1/user.proto        package users.v1;

one invocation produces:

gen/common/money.pb.go
gen/orders/v1/order.pb.go   (+ _grpc)
gen/users/v1/user.pb.go     (+ _grpc)
gen/openapi.yaml

Each directory becomes its own Go package (managed mode derives go_package from the path), cross-package imports resolve, and the generated code compiles as a set.

Note: OpenAPI is written as a single openapi.yaml per run. For separate specs per application, run protogen once per application directory.