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proto v0.53 - New exec command and backend configuration

· 3 min read
Miles Johnson
Miles Johnson
Founder, developer

In this release, we're introducing another way to execute tools within proto.

New proto exec command​

Since proto's inception, we've had the proto run command for executing a specific tool with a list of arguments. While this works well for simple use-cases, like our shims layer, it has some limitations, such as:

  • It only works with one tool at a time, not multiple.
  • It cannot bootstrap the environment (vars and paths).
  • It cannot execute arbitrary commands.
  • It requires a tool to have a primary/main executable (not everything does).
  • Executing a secondary executable is not straightforward.

To address these limitations, we're introducing a new command, proto exec! This command is designed to bootstrap the environment with any numbers of tools, and execute an arbitrary command within that environment.

For example, say we want to run a backend application that requires Node.js, pnpm, and Ruby, we can do the following:

$ proto exec node@24 pnpm@10 ruby@3.4 -- pnpm run app:start

This will load and activate these three tools, set environment variables, update PATH, and execute the command! Pretty nifty, right? It even supports executing the command within a shell! Head to the docs for more information.

Backend configuration support​

In our previous release, we updated backend plugins with user-driven support, instead of being hard-coded into proto core. To build upon this, we've improved the interoperability of backends by supporting configuration of the backend itself (not the tool that the backend represents), using the new [backends] setting.

For example, say you're using asdf:zig, which is the zig tool in the asdf backend. To configure the tool, you would use [tools."asdf:zig"], but to configure the asdf backend itself, you can now use [backends.asdf].

.prototools
[backends.asdf]
backend-setting = "value"

[tools."asdf:zig"]
tool-setting = "value"

Backend configuration is useful where you want to control the behavior of the backend itself and apply it to all tools, while backend-managed tool configuration is useful when you want to control the behavior of a specific tool.

warning

In previous versions, configuring a backend-managed tool was done without the backend prefix, for example [tools.zig]. To avoid collision with non-backend-managed tools, this is no longer supported, and you must use the full locator, for example [tools."asdf:zig"].

Other changes​

View the official release for a full list of changes.

  • Added a mechanism for plugins to setup the environment during activation and execution workflows.
  • Fixed an issue where shims that belong to a backend would fail to run.

Looking for contributors​

We have a lot of cool stuff planned for proto, like more official backends and tools, improved workflows, an official registry, and more! So if you're interested in Rust or WASM, we would love and appreciate your help. Feel free to ping us on Discord!