Add per-session env overrides for built-in shell tool child processes

Open
#2,040 0 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
45/100
Issue type
Feature
Clarity
Mostly clear
Activity status
Quiet
Tech stack
shell, typescript
Domain
api, cli

Research direction

Start by tracing the ShellOptions wire shape and session.rpc.options.update handling described in the issue. Review how shell and initScripts behave across updates and resume, then pin down replacement, precedence, null-removal, and persistence semantics; done means the env overlay is represented and applied consistently to built-in shell child processes.

Written by the indexing model from the issue text.

Description

enhancement vs-code

Follow up to #1911. The initScripts half of that ask shipped through the runtime in github/copilot-agent-runtime#12710, but the per-session env part was deferred out of that PR.

Context: https://github.com/microsoft/vscode/issues/323164

initScripts covers the Python activation case since the host can materialize a shell-specific activation file and have the runtime source it before each command. An explicit env map is still worth having for hosts that just want to set or unset a few variables without generating script files, and without dealing with per-shell quoting.

Current wire shape:

export interface ShellOptions {
    initProfile?: "none" | "non-interactive";
    initScripts?: ShellInitScript[];
    processFlags?: string[];
}

Add the env map from the original proposal:

export interface ShellOptions {
    /** Env applied to built-in shell tool child processes. `null` unsets/removes. */
    env?: Record<string, string | null>;
}

The reason this was deferred is that the update semantics should be pinned down before the wire shape ships:

  • Whether session.rpc.options.update with shell.env replaces the whole overlay or merges per key. Replace seems right: it stays idempotent and a host can revert a variable to the inherited value by omitting it. With merge there is no way to un-touch a variable once set.
  • Precedence: overlay applied to the spawned process env first, initScripts sourced after, so scripts can override.
  • null meaning remove-from-env vs revert-to-inherited.
  • Whether the overlay persists across resume or the host re-sends it, matching how the rest of shell behaves today.

(generated by copilot)

Dominant language
Java
Stars
10.5k
Forks
1.5k
Avg merge
1d 12h
Merged PRs (30d)
133

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

More from github/copilot-sdk

All issues in github/copilot-sdk

Similar issues

More Java issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.