pick-copilot-tag - SKILL.md Agent Skill

name: pick-copilot-tag description: Determine which vscode-copilot-chat release tag to use for a Positron build

Pick Copilot Tag

Determine which microsoft/vscode-copilot-chat release tag is compatible with a given Positron build by checking API proposal version compatibility.

When to Use

Use this skill when:

Deciding which copilot-chat tag to merge after an upstream Code OSS update
A release build rejects copilot-chat with "API proposals not compatible"
Upgrading copilot-chat and need to find the latest compatible tag

Prerequisites

GitHub CLI (gh) installed and authenticated
jq and python3 available

Workflow

Step 1: Run the Check

From the Positron repo root, run the script with no arguments. It will automatically read package.json for the Code OSS version, extract proposals from the source tree, discover compatible tag series, and check them all:

.claude/skills/pick-copilot-tag/scripts/check-proposals.sh

For checking against a built Positron app instead of the source tree:

.claude/skills/pick-copilot-tag/scripts/check-proposals.sh --app /Applications/Positron.app

To check against a specific Positron release (fetches both proposals and the Code OSS version from the release tag on GitHub):

.claude/skills/pick-copilot-tag/scripts/check-proposals.sh --positron-version 2026.03.0

To check a specific tag series (skips auto-discovery):

.claude/skills/pick-copilot-tag/scripts/check-proposals.sh --tag-series v0.37

Flags can be combined, e.g. --positron-version 2026.03.0 --tag-series v0.37.

Step 2: Report Results

The script outputs each tag as OK or BAD with specific mismatches. Report:

The latest compatible tag (first OK in descending version order)
What breaks in newer tags (which proposals changed)
A recommendation

Use -v / --verbose to show the full proposals list instead of just the count. Use --pre-releases to also check date-based pre-release tags (skipped by default).

Example Output

Positron proposals: 9 versioned (from src/vs/.../extensionsApiProposals.ts)

Code OSS version: 1.109.0
Checking recent tag series for engine compatibility:
  v0.36 -> ^1.108.0 (compatible)
  v0.37 -> ^1.109.0 (compatible)
  v0.38 -> ^1.110.0 (needs Code OSS >= 1.110.0)

--- v0.37 ---
Releases (10 tags):
BAD v0.37.9
   chatHooks@6 (not in Positron)
   chatParticipantPrivate@13 (Positron has chatParticipantPrivate@12)
BAD v0.37.6
   chatHooks@6 (not in Positron)
OK  v0.37.5
Pre-releases (41 tags, skipped -- use --pre-releases to check)

Latest compatible release: v0.37.5