name: add-policy description: Use when adding, modifying, or reviewing VS Code configuration policies. Covers the full policy lifecycle from registration to export to platform-specific artifacts. Run on ANY change that adds a policy: field to a configuration property.

Adding a Configuration Policy

Policies allow enterprise administrators to lock configuration settings via OS-level mechanisms (Windows Group Policy, macOS managed preferences, Linux config files) or via Copilot account-level policy data. This skill covers the complete procedure.

When to Use

• Adding a new policy: field to any configuration property
• Modifying an existing policy (rename, category change, etc.)
• Reviewing a PR that touches policy registration
• Adding account-based policy support via IPolicyData
• Wiring an enterprise managed setting (native MDM / GitHub server) — see github-managed-settings.md
• Having one policy govern multiple settings via policyReference
• Testing account/managed-settings policies locally without the real backend — see local-testing.md

Architecture Overview

Policy Sources (layered, last writer wins)

Key Files

Procedure

Step 1 — Add the policy field to the configuration property

Find the configuration registration (typically in a *.contribution.ts file) and add a policy object to the property schema.

Required fields:

Determining minimumVersion: Always read version from the root package.json and use the major.minor portion. For example, if package.json has "version": "1.112.0", use minimumVersion: '1.112'. Never hardcode an old version like '1.99'.

policy: {
    name: 'MyPolicyName',                          // PascalCase, unique across all policies
    category: PolicyCategory.InteractiveSession,    // From PolicyCategory enum
    minimumVersion: '1.112',                        // Use major.minor from package.json version
    localization: {
        description: {
            key: 'my.config.key',                   // NLS key for the description
            value: nls.localize('my.config.key', "Human-readable description."),
        }
    }
}

Optional: value function for account-based policy:

If this policy should also be controllable via Copilot account policy data (from IPolicyData), add a value function:

policy: {
    name: 'MyPolicyName',
    category: PolicyCategory.InteractiveSession,
    minimumVersion: '1.112',                        // Use major.minor from package.json version
    value: (policyData) => policyData.my_field === false ? false : undefined,
    localization: { /* ... */ }
}

The value function receives IPolicyData (from src/vs/base/common/defaultAccount.ts) and should:

• Return a concrete value to override the user's setting
• Return undefined to not apply any account-level override (falls through to OS policy or user setting)

If you need a new field on IPolicyData, add it to the interface in src/vs/base/common/defaultAccount.ts.

Optional: enumDescriptions for enum/string policies:

IMPORTANT: If the configuration property has type: 'string' and an enum array, you must include enumDescriptions in the localization block with the same number of entries as the enum array. Without this, npm run export-policy-data will fail with: enumDescriptions must exist and have the same length as enum for policy "...".

localization: {
    description: { key: '...', value: nls.localize('...', "...") },
    enumDescriptions: [
        { key: 'opt.none', value: nls.localize('opt.none', "No access.") },
        { key: 'opt.all', value: nls.localize('opt.all', "Full access.") },
    ]
}

Step 2 — Ensure PolicyCategory is imported

import { PolicyCategory } from '../../../../base/common/policy.js';

Existing categories in the PolicyCategory enum:

• Extensions
• IntegratedTerminal
• InteractiveSession (used for all chat/Copilot policies)
• Telemetry
• Update

If you need a new category, add it to PolicyCategory in src/vs/base/common/policy.ts and add corresponding PolicyCategoryData localization.

Step 3 — Validate TypeScript compilation

Check the VS Code - Build watch task output, or run:

npm run typecheck-client

Step 4 — Export the policy data

Regenerate the auto-generated policy catalog:

npm run export-policy-data

This script handles transpilation, sets up GITHUB_TOKEN (via gh CLI or GitHub OAuth device flow), and runs --export-policy-data. The export command reads extension configuration policies from the distro's product.json via the GitHub API and merges them into the output.

This updates build/lib/policies/policyData.jsonc. Never edit this file manually. Verify your new policy appears in the output. You will need code review from a codeowner to merge the change to main.

Policy for extension-provided settings

Extension authors cannot add policy: fields directly—their settings are defined in the extension's package.json, not in VS Code core. Instead, policies for extension settings are defined in vscode-distro's product.json under the extensionConfigurationPolicy key.

How it works

1. Source of truth: The extensionConfigurationPolicy map lives in vscode-distro under mixin/{quality}/product.json (stable, insider, exploration).
2. Runtime: When VS Code starts with a distro-mixed product.json, configurationExtensionPoint.ts reads extensionConfigurationPolicy and attaches matching policy objects to extension-contributed configuration properties.
3. Export/build: The --export-policy-data command fetches the distro's product.json at the commit pinned in package.json and merges extension policies into the output. Use npm run export-policy-data which sets up authentication automatically.

Distro format

Each entry in extensionConfigurationPolicy must include:

"extensionConfigurationPolicy": {
    "publisher.extension.settingName": {
        "name": "PolicyName",
        "category": "InteractiveSession",
        "minimumVersion": "1.99",
        "description": "Human-readable description."
    }
}

• name: PascalCase policy name, unique across all policies
• category: Must be a valid PolicyCategory enum value (e.g., InteractiveSession, Extensions)
• minimumVersion: The VS Code version that first shipped this policy
• description: Human-readable description string used to generate localization key/value pairs for ADMX/ADML/macOS/Linux policy artifacts

Adding a new extension policy

1. Add the entry to extensionConfigurationPolicy in all three quality product.json files in vscode-distro (mixin/stable/, mixin/insider/, mixin/exploration/)
2. Update the distro commit hash in package.json to point to the distro commit that includes your new entry — the export command fetches extension policies from the pinned distro commit
3. Regenerate policyData.jsonc by running npm run export-policy-data (see Step 4 above)
4. Update the test fixture at src/vs/workbench/contrib/policyExport/test/node/extensionPolicyFixture.json with the new entry

Test fixtures

The file src/vs/workbench/contrib/policyExport/test/node/extensionPolicyFixture.json is a test fixture that must stay in sync with the extension policies in the checked-in policyData.jsonc. When extension policies are added or changed in the distro, this fixture must be updated to match — otherwise the integration test will fail because the test output (generated from the fixture) won't match the checked-in file (generated from the real distro).

Downstream consumers

GitHub Preview Features

If your setting is a GitHub Preview Feature — meaning it's a Copilot/chat feature that organizations can disable via their GitHub account-level policy — you must add a value function that checks policyData.chat_preview_features_enabled.

When to add this flag

Add the chat_preview_features_enabled check when all of these apply:

• The setting controls a Copilot or chat feature (e.g., agent tools, hooks, MCP, auto-approve)
• The feature is in preview or experimental status (typically tagged 'preview' or 'experimental')
• An organization admin should be able to disable it for all users in their org via GitHub account policy

How it works

The chat_preview_features_enabled field on IPolicyData (defined in src/vs/base/common/defaultAccount.ts) is populated from the user's GitHub Copilot token entitlements. When an organization admin disables preview features, chat_preview_features_enabled is set to false.

Pattern

Add a value function to the policy that returns a disabling value when chat_preview_features_enabled === false, and undefined otherwise (to fall through to the user's own setting):

policy: {
    name: 'MyPreviewFeaturePolicy',
    category: PolicyCategory.InteractiveSession,
    minimumVersion: '1.xx', // Must match the first VS Code release that ships this policy.
    value: (policyData) => policyData.chat_preview_features_enabled === false ? false : undefined,
    localization: {
        description: {
            key: 'my.setting.description',
            value: nls.localize('my.setting.description', "Description of the setting."),
        }
    }
}

Key details:

• Always compare with === false, not !policyData.chat_preview_features_enabled — the field is optional and undefined means "no policy data available", which should not disable the feature.
• Return undefined when the flag is not false so the account-level policy does not override the user's setting.
• Return the disabling value for the setting's type: false for booleans, a restrictive string/enum value for other types.

Real-world examples

See chat.tools.global.autoApprove and chat.useHooks in src/vs/workbench/contrib/chat/browser/chat.shared.contribution.ts for existing settings that use this pattern.

Enterprise Managed Settings (native MDM / GitHub server)

GitHub Copilot enterprise admins can lock settings through a managed-settings bag. VS Code feeds the bag from two channels: native MDM (Windows registry / macOS plist) and the GitHub /copilot_internal/managed_settings endpoint. (The external managed-settings-schema.json also describes a managed-settings.json file channel, but VS Code does not read such a file.) Both VS Code channels converge on IPolicyData.managedSettings (a flat dot-path bag) and are consumed by the existing policy.value(policyData) callback — there is no new IPolicyService.

To drive a policy from a managed setting, declare managedSettings on the policy and read policyData.managedSettings?.[KEY] in value (the real ChatToolsAutoApprove also ORs in chat_preview_features_enabled === false):

// Existing policy shown verbatim; `minimumVersion: '1.99'` is its historical value —
// a NEW policy derives minimumVersion from package.json major.minor (see Step 1).
policy: {
    name: 'ChatToolsAutoApprove',
    category: PolicyCategory.InteractiveSession,
    minimumVersion: '1.99',
    value: (policyData) =>
        policyData.managedSettings?.[COPILOT_DISABLE_BYPASS_PERMISSIONS_MODE_KEY] === 'disable'
            || policyData.chat_preview_features_enabled === false ? false : undefined,
    managedSettings: {
        [COPILOT_DISABLE_BYPASS_PERMISSIONS_MODE_KEY]: { type: 'string' },
    },
    localization: { /* ... */ }
}

This is its own modality — full details, schema source of truth, helpers, wiring, and the new-key checklist are in github-managed-settings.md. Read it before adding or reviewing any managed-settings key.

Testing locally: to exercise the account/managed-settings flow without the real GitHub backend, use the mock policy server — see local-testing.md.

One Policy for Many Settings (policyReference)

A single policy can govern multiple settings (e.g. gate an agent in both the editor window and the Agents window). The owner declares the full policy: { name, … }; other settings declare policyReference: { name } pointing at the owner's policy name.

// Owner setting (existing policy; `minimumVersion: '1.126'` is its historical value —
// a NEW policy uses package.json major.minor, see Step 1)
policy: { name: 'Codex3PIntegration', category: PolicyCategory.InteractiveSession, minimumVersion: '1.126', /* ... */ }

// Subordinate setting (no type/value/localization of its own)
policyReference: { name: 'Codex3PIntegration' }

policyReference is not managed-settings-specific: use it whenever one enterprise policy should lock multiple settings to the same value. The reference is a pure pointer. It contributes no type, value, managedSettings, restrictedValue, or localization of its own; the owner remains the single source of truth for policy metadata and runtime behavior.

Key rules and internals:

• A setting must not declare both policy and policyReference (rejected during configuration registration).
• Exactly one setting may own a policy name with policy; additional settings attach with policyReference.
• The reference setting's type must match the owner's type; npm run export-policy-data enforces this because the same resolved policy value is applied verbatim to owner and references.
• ConfigurationRegistry.getPolicyReferenceConfigurations() tracks policyName → Set<settingKey>, and PolicyConfiguration updates both the owner setting and all registered references when the policy value changes.
• AbstractPolicyService.serialize() uses toSerializablePolicyDefinition() to strip the non-cloneable value() callback before sending policy definitions over IPC.
• AbstractPolicyService.updatePolicyDefinitions() replaces definitions per policy name, so a late-registering owner supersedes an earlier reference fallback; if the owner is removed, a reference can still provide a bare type fallback.
• Exported policy data includes referencedSettings for references that are registered during export, and Developer: Policy Diagnostics lists registered owner/reference settings under the same policy name.

For managed-settings-specific examples that combine policyReference with Copilot managed settings, see github-managed-settings.md.

Examples

Search the codebase for policy: to find all the examples of different policy configurations.

Learnings

• Never hand-edit build/lib/policies/policyData.jsonc (its header explicitly forbids it). If npm run export-policy-data is failing, fix the script — don't patch the JSON. Common cause: running it in the wrong working directory (e.g. main repo instead of a worktree), which silently exports the wrong source tree.
• Regenerate policyData.jsonc in a clean environment, or the PolicyExport integration test will fail in CI. referencedSettings is only captured for references loaded at export time. A plain npm run export-policy-data loads your dev-profile extensions (e.g. the Copilot extension), which injects referencedSettings onto core policies that the test's fixture-based export (clean profile, no user extensions) won't produce — so the checked-in file ends up with extra referencedSettings and CI fails. This is not reproducible locally because the test reuses your default extensions dir. Regenerate the way the test exports: DISTRO_PRODUCT_JSON=<extensionPolicyFixture.json> ./scripts/code.sh --export-policy-data="$PWD/build/lib/policies/policyData.jsonc" --user-data-dir="$(mktemp -d)" --extensions-dir="$(mktemp -d)" (with VSCODE_SKIP_PRELAUNCH=1).
• Document behavior and business-logic expectations, not copy-pasted implementation. Reproducing internal code (e.g. the getPolicyData() merge body) in the skill rots the moment the source changes and adds no information beyond the source itself. State the contract in prose (e.g. "native MDM managed settings win over the server-delivered channel; the two layers are never merged") and point to the source for the implementation. Reserve code blocks for the author-facing API contract a contributor must follow — how to declare a policy / managedSettings / value callback — not for restating runtime plumbing.