diff --git a/.github/workflows/package-drift.yml b/.github/workflows/package-drift.yml
new file mode 100644
index 00000000..d732b318
--- /dev/null
+++ b/.github/workflows/package-drift.yml
@@ -0,0 +1,41 @@
+name: Package Drift
+
+# Read-only drift detection for npm package publishing access, comparing the
+# live registry against src/config/packageAccess.ts. Mutations are applied by
+# a human via the generated remediation plan (npm requires an interactive 2FA
+# challenge for all governance writes); PyPI has no API and is not checked.
+#
+# Requires the NPM_READ_TOKEN secret: a read-only npm granular access token
+# with organization read access to "modelcontextprotocol". When the secret is
+# absent the check prints a skip notice and passes (same optional-credential
+# pattern as the Discord integration).
+
+on:
+  schedule:
+    - cron: '0 14 * * 1' # Mondays 14:00 UTC
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  npm-drift:
+    name: npm package access drift
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Check npm package access drift
+        env:
+          NPM_TOKEN: ${{ secrets.NPM_READ_TOKEN }}
+        run: npm run check-package-drift
diff --git a/README.md b/README.md
index 85e126d7..030c7ee3 100644
--- a/README.md
+++ b/README.md
@@ -12,6 +12,7 @@ Infrastructure as Code for managing access to MCP community resources using Pulu
 - **Google Workspace Groups**: Automatically syncs group memberships for @modelcontextprotocol.io email accounts
   - **Email Groups**: Groups with `isEmailGroup: true` accept emails from anyone (including external users) and notify all members. External posts are moderated for security.
 - **Google Workspace User Accounts**: Provisions @modelcontextprotocol.io accounts for members of roles with `provisionUser: true` (directly, or via a role nested under one through `github.parent` — e.g. SDK teams under `sdk-maintainers`, working groups under `working-groups`)
+- **npm & PyPI Package Publishing Access** (declared, not applied): Expected registry access is declared in [`src/config/packageAccess.ts`](src/config/packageAccess.ts) and drift against the live npm registry is detected by CI — but changes are applied manually by a maintainer. See [npm & PyPI Package Publishing Access](#npm--pypi-package-publishing-access) below for why and how.
 
 ### Opting in to a Google Workspace account (maintainers)
 
@@ -30,6 +31,34 @@ If you're a maintainer — explicitly or implicitly (SDK maintainers, working gr
 
 Once merged, Pulumi provisions the account. An admin will share your initial password (retrievable via `pulumi stack output --show-secrets newGWSUserPasswords`).
 
+## npm & PyPI Package Publishing Access
+
+Publishing access to the `modelcontextprotocol` npm organization and to the MCP PyPI projects is **config-as-code with human-applied changes** — deliberately outside the Pulumi resource graph:
+
+- **npm** has an official management API ([api-docs.npmjs.com](https://api-docs.npmjs.com/)), but since August 2026 every governance mutation (org/team membership, maintainer add/remove, trusted-publisher config, token management) requires an **interactive 2FA challenge** — tokens, even with "bypass 2FA", get `403`. Reads still work headless with a granular access token, so drift is detected automatically and remediated manually.
+- **PyPI** has **no management API at all**: collaborators, trusted publishers, and organizations are web-UI only, and maintainer invites must be accepted by email. The PyPI section of the config is declared state for audit purposes plus the manual procedures below.
+
+What lives where:
+
+- [`src/config/packageAccess.ts`](src/config/packageAccess.ts) — expected npm org membership (derived from members' `npm` field in `users.ts`), per-package maintainers and trusted publishers for the key packages, a default policy for the rest of the org's packages, and declared PyPI project rosters.
+- [`scripts/check-package-drift.ts`](scripts/check-package-drift.ts) — read-only npm drift check: `NPM_TOKEN=<token> npm run check-package-drift`. Prints a drift report and a remediation plan of `npm` CLI commands; exits nonzero on drift, and skips gracefully when `NPM_TOKEN` is unset.
+- [`.github/workflows/package-drift.yml`](.github/workflows/package-drift.yml) — runs the check weekly and on demand, using the optional `NPM_READ_TOKEN` secret (a read-only npm granular access token with organization read access; note write-capable npm tokens expire after at most 90 days, so keep this one read-only).
+
+### Applying npm changes (runbook)
+
+1. Edit `src/config/packageAccess.ts` / `users.ts` to the desired state and merge the PR.
+2. Run the drift check locally with a read-only token: `NPM_TOKEN=<token> npm run check-package-drift`.
+3. Review the printed remediation plan — especially any removal commands.
+4. As an npm org owner, execute the plan in **one interactive session**: log in with `npm login`, trigger a 2FA prompt (e.g. run the first command), and choose **"Don't ask again for 5 minutes"** on the npmjs.com challenge. npm's own bulk guidance is to script the commands with a `sleep 2` between calls — roughly 80 operations fit in one approval window.
+5. Re-run the drift check to confirm it exits clean.
+
+### PyPI procedures (manual, web UI only)
+
+- **Add a maintainer**: Manage project → Collaborators → invite by PyPI username with the Maintainer (upload only) or Owner role. The invitee must accept the invitation email before the role takes effect. Afterwards, record the account in `packageAccess.ts` and on the member's `pypi` field.
+- **Trusted publisher**: Manage project → Publishing → add the GitHub repository + workflow (multiple publishers per project are allowed). Prefer trusted publishing over project-scoped API tokens.
+- **Recommended follow-up**: apply for a free [PyPI community organization](https://docs.pypi.org/organization-accounts/) so projects are org-owned and access is managed via teams rather than per-project role edits.
+- **Naming constraint**: the PyPI project name `modelcontextprotocol` is registered by an unrelated third party, so MCP's Python packages live under `mcp*` names. Any future consolidation under that name would require a [PEP 541](https://peps.python.org/pep-0541/) name-transfer request or simply keeping the `mcp*` naming.
+
 ## Deployment
 
 ### Production Deployment (Automated)
diff --git a/package.json b/package.json
index 47aabb9d..7f0c50d9 100644
--- a/package.json
+++ b/package.json
@@ -7,6 +7,7 @@
     "build": "tsc",
     "validate": "npx ts-node scripts/validate-config.ts",
     "test": "npx ts-node scripts/test-config.ts",
+    "check-package-drift": "npx ts-node scripts/check-package-drift.ts",
     "check": "npm run format:check && npm run validate && npm run test",
     "format": "prettier --write .",
     "format:check": "prettier --check ."
diff --git a/scripts/check-package-drift.ts b/scripts/check-package-drift.ts
new file mode 100644
index 00000000..ddead76a
--- /dev/null
+++ b/scripts/check-package-drift.ts
@@ -0,0 +1,313 @@
+#!/usr/bin/env npx ts-node
+
+/**
+ * Compares live npm registry state against the expected state declared in
+ * src/config/packageAccess.ts and prints a drift report plus a remediation
+ * plan of npm CLI commands for a maintainer to run in a single interactive
+ * 2FA-authenticated session (see "npm & PyPI Package Publishing Access" in
+ * the README).
+ *
+ * Read-only: this script never mutates anything. All npm write operations
+ * require an interactive 2FA challenge (since August 2026), which is why the
+ * remediation is a human-executed plan instead of automation. PyPI has no
+ * management API at all and is not checked here.
+ *
+ * Run with: NPM_TOKEN=<read-only granular access token> npx ts-node scripts/check-package-drift.ts
+ *
+ * - Without NPM_TOKEN: prints a skip notice and exits 0 (so CI without the
+ *   secret is a graceful no-op, mirroring the optional Discord credentials).
+ * - With NPM_TOKEN: exits 1 when drift is found, 0 when clean.
+ */
+
+import {
+  NPM_ORG,
+  NPM_PACKAGES,
+  NPM_DEFAULT_POLICY,
+  getNpmPackageAccess,
+  getExpectedNpmOrgMembers,
+} from '../src/config/packageAccess';
+
+const REGISTRY = 'https://registry.npmjs.org';
+const REQUEST_DELAY_MS = 150;
+
+const token = process.env.NPM_TOKEN;
+
+interface Drift {
+  description: string;
+  /** Remediation lines; lines starting with '#' are guidance, not commands */
+  commands: readonly string[];
+}
+
+const drifts: Drift[] = [];
+const warnings: string[] = [];
+
+function sleep(ms: number): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+async function registryGet(path: string): Promise<{ status: number; body: unknown }> {
+  const url = `${REGISTRY}${path}`;
+  let lastError: unknown;
+  for (let attempt = 0; attempt < 3; attempt++) {
+    if (attempt > 0) await sleep(2000 * attempt);
+    try {
+      const response = await fetch(url, {
+        headers: { authorization: `Bearer ${token}` },
+      });
+      if (response.status >= 500) {
+        lastError = new Error(`HTTP ${response.status} from ${url}`);
+        continue;
+      }
+      let body: unknown = null;
+      try {
+        body = await response.json();
+      } catch {
+        // Non-JSON body (e.g. empty 404) — leave as null
+      }
+      return { status: response.status, body };
+    } catch (e) {
+      lastError = e;
+    }
+  }
+  throw lastError;
+}
+
+/**
+ * Escape a package name for use as a registry URL path segment. Follows the
+ * npm CLI's convention for scoped packages: keep the leading '@' literal and
+ * percent-encode every '/'.
+ */
+function escapePackageName(packageName: string): string {
+  return packageName.replace(/\//g, '%2F');
+}
+
+function diffSets(
+  expected: readonly string[],
+  actual: readonly string[]
+): { missing: string[]; unexpected: string[] } {
+  const expectedSet = new Set(expected);
+  const actualSet = new Set(actual);
+  return {
+    missing: expected.filter((e) => !actualSet.has(e)).sort(),
+    unexpected: actual.filter((a) => !expectedSet.has(a)).sort(),
+  };
+}
+
+async function checkOrgMembership(): Promise<void> {
+  const { status, body } = await registryGet(`/-/org/${NPM_ORG}/user`);
+  if (status !== 200 || typeof body !== 'object' || body === null) {
+    warnings.push(
+      `Could not read org roster (GET /-/org/${NPM_ORG}/user returned ${status}). ` +
+        `The token likely lacks organization read access — org membership was NOT checked.`
+    );
+    return;
+  }
+
+  const roster = body as Record<string, string>;
+  const actual = Object.keys(roster);
+  if (actual.length === 0) {
+    warnings.push(
+      `Org roster came back empty — unauthenticated requests see an empty roster, ` +
+        `so the token likely lacks organization access. Org membership was NOT checked.`
+    );
+    return;
+  }
+
+  const { missing, unexpected } = diffSets(getExpectedNpmOrgMembers(), actual);
+  for (const user of missing) {
+    drifts.push({
+      description: `Org member missing: "${user}" is expected in the "${NPM_ORG}" org but is not a member`,
+      commands: [`npm org set ${NPM_ORG} ${user} developer`],
+    });
+  }
+  for (const user of unexpected) {
+    drifts.push({
+      description:
+        `Unexpected org member: "${user}" (role: ${roster[user]}) is in the "${NPM_ORG}" org ` +
+        `but not declared in packageAccess.ts/users.ts`,
+      commands: [
+        `# Either add npm: '${user}' to the right member in src/config/users.ts (or UNMAPPED_NPM_USERS), or remove them:`,
+        `npm org rm ${NPM_ORG} ${user}`,
+      ],
+    });
+  }
+}
+
+async function listOrgPackages(): Promise<string[]> {
+  const { status, body } = await registryGet(`/-/org/${NPM_ORG}/package`);
+  if (status === 200 && typeof body === 'object' && body !== null) {
+    return Object.keys(body as Record<string, string>).sort();
+  }
+  warnings.push(
+    `Could not enumerate org packages (GET /-/org/${NPM_ORG}/package returned ${status}); ` +
+      `falling back to the ${NPM_PACKAGES.length} explicitly declared packages.`
+  );
+  return NPM_PACKAGES.map((p) => p.package);
+}
+
+/** Extract candidate trusted-publisher configs from a /trust response, defensively. */
+function extractTrustConfigs(body: unknown): Array<Record<string, unknown>> {
+  if (body === null || typeof body !== 'object') return [];
+  if (Array.isArray(body)) return body.filter((c) => typeof c === 'object' && c !== null);
+  const obj = body as Record<string, unknown>;
+  for (const key of ['objects', 'configurations', 'trustedPublishers', 'trust']) {
+    if (Array.isArray(obj[key])) {
+      return (obj[key] as unknown[]).filter(
+        (c): c is Record<string, unknown> => typeof c === 'object' && c !== null
+      );
+    }
+  }
+  return [obj];
+}
+
+async function checkPackage(packageName: string): Promise<void> {
+  const expected = getNpmPackageAccess(packageName);
+  const isExplicit = NPM_PACKAGES.some((p) => p.package === packageName);
+
+  // 1) Maintainers, from the public package document
+  const { status, body } = await registryGet(`/${escapePackageName(packageName)}`);
+  if (status !== 200 || typeof body !== 'object' || body === null) {
+    warnings.push(`Could not read package document for ${packageName} (HTTP ${status}).`);
+    return;
+  }
+  const packument = body as {
+    maintainers?: Array<{ name?: string }>;
+    'dist-tags'?: Record<string, string>;
+    versions?: Record<string, { _npmUser?: { trustedPublisher?: unknown } }>;
+  };
+
+  const actualMaintainers = (packument.maintainers ?? [])
+    .map((m) => m.name)
+    .filter((name): name is string => typeof name === 'string');
+  const { missing, unexpected } = diffSets(expected.maintainers, actualMaintainers);
+  for (const user of missing) {
+    drifts.push({
+      description: `Maintainer missing on ${packageName}: "${user}"`,
+      commands: [`npm owner add ${user} ${packageName}`],
+    });
+  }
+  for (const user of unexpected) {
+    drifts.push({
+      description:
+        `Unexpected maintainer on ${packageName}: "${user}" ` +
+        `(not in its ${isExplicit ? 'declared maintainers' : 'default-policy maintainers'})`,
+      commands: [
+        `# Either declare "${user}" for this package in src/config/packageAccess.ts, or remove them:`,
+        `npm owner rm ${user} ${packageName}`,
+      ],
+    });
+  }
+
+  // 2) Trusted publishing of the latest release (default policy)
+  const latestVersion = packument['dist-tags']?.latest;
+  const latest = latestVersion ? packument.versions?.[latestVersion] : undefined;
+  if (NPM_DEFAULT_POLICY.requireTrustedPublishing && latest && !latest._npmUser?.trustedPublisher) {
+    drifts.push({
+      description:
+        `${packageName}@${latestVersion} was not published via trusted publishing ` +
+        `(policy: all org packages publish via OIDC)`,
+      commands: [
+        `# Configure a trusted publisher for ${packageName} (web UI: package Settings -> Trusted publishing,`,
+        `# or \`npm trust\` on npm >= 11.15.0), then stop using publish tokens for it.`,
+      ],
+    });
+  }
+
+  // 3) Declared trusted-publisher configuration (explicit packages only)
+  if (expected.trustedPublisher) {
+    const want = expected.trustedPublisher;
+    const trust = await registryGet(`/-/package/${escapePackageName(packageName)}/trust`);
+    if (trust.status === 401 || trust.status === 403) {
+      warnings.push(
+        `Cannot read trusted-publisher config for ${packageName} (HTTP ${trust.status}); ` +
+          `token lacks permission — declared publisher (${want.repository} ${want.workflow}) was NOT verified.`
+      );
+    } else if (trust.status === 404 || extractTrustConfigs(trust.body).length === 0) {
+      drifts.push({
+        description: `No trusted publisher configured on ${packageName} (expected ${want.repository} via ${want.workflow})`,
+        commands: [
+          `# Configure trusted publishing for ${packageName}: GitHub Actions, repository ${want.repository},`,
+          `# workflow ${want.workflow} (web UI: package Settings -> Trusted publishing, or \`npm trust\`).`,
+        ],
+      });
+    } else if (trust.status === 200) {
+      const configs = extractTrustConfigs(trust.body);
+      const matches = configs.some((c) => {
+        const text = JSON.stringify(c);
+        const repoOk =
+          text.includes(want.repository) ||
+          (text.includes(want.repository.split('/')[0]) &&
+            text.includes(want.repository.split('/')[1]));
+        const workflowFile = want.workflow.split('/').pop() ?? want.workflow;
+        return repoOk && text.includes(workflowFile);
+      });
+      if (!matches) {
+        drifts.push({
+          description:
+            `Trusted publisher mismatch on ${packageName}: expected ${want.repository} via ${want.workflow}, ` +
+            `live config differs: ${JSON.stringify(configs)}`,
+          commands: [
+            `# Update trusted publishing for ${packageName} to repository ${want.repository},`,
+            `# workflow ${want.workflow} (web UI: package Settings -> Trusted publishing, or \`npm trust\`).`,
+          ],
+        });
+      }
+    }
+  }
+}
+
+async function main(): Promise<void> {
+  if (!token) {
+    console.log('NPM_TOKEN is not set — skipping npm package access drift check.');
+    console.log(
+      'Provide a read-only granular access token with organization read access to enable it.'
+    );
+    process.exit(0);
+  }
+
+  console.log(`Checking npm package access drift for org "${NPM_ORG}"...\n`);
+
+  await checkOrgMembership();
+
+  const packages = await listOrgPackages();
+  console.log(`Checking ${packages.length} packages...`);
+  const declared = new Set(NPM_PACKAGES.map((p) => p.package));
+  const notInOrg = [...declared].filter((p) => !packages.includes(p));
+  for (const pkg of notInOrg) {
+    warnings.push(`Declared package ${pkg} was not found in the org package list.`);
+  }
+  for (const pkg of packages) {
+    await checkPackage(pkg);
+    await sleep(REQUEST_DELAY_MS);
+  }
+
+  // Report
+  if (warnings.length > 0) {
+    console.log('\n--- Warnings (not drift) ---');
+    for (const warning of warnings) console.log(`  ! ${warning}`);
+  }
+
+  if (drifts.length === 0) {
+    console.log('\nNo drift detected. Live npm state matches src/config/packageAccess.ts.');
+    process.exit(0);
+  }
+
+  console.log(`\n--- Drift report (${drifts.length} finding${drifts.length === 1 ? '' : 's'}) ---`);
+  for (const drift of drifts) console.log(`  ✗ ${drift.description}`);
+
+  console.log('\n--- Remediation plan ---');
+  console.log('# Review, then run in ONE interactive npm session (logged in as an org owner).');
+  console.log('# Approve a 2FA challenge on npmjs.com and choose "Don\'t ask again for 5 minutes"');
+  console.log('# to batch these; add `sleep 2` between commands in longer batches.');
+  console.log('# See "npm & PyPI Package Publishing Access" in the README.\n');
+  for (const drift of drifts) {
+    for (const command of drift.commands) console.log(command);
+  }
+
+  process.exit(1);
+}
+
+main().catch((e) => {
+  console.error(`Drift check failed: ${e}`);
+  process.exit(1);
+});
diff --git a/scripts/test-config.ts b/scripts/test-config.ts
index 3ef1a9c3..6aa6b99b 100644
--- a/scripts/test-config.ts
+++ b/scripts/test-config.ts
@@ -9,6 +9,14 @@ import { ROLES, buildRoleLookup, getRolesForPlatform } from '../src/config/roles
 import { ROLE_IDS, isValidRoleId } from '../src/config/roleIds';
 import { MEMBERS } from '../src/config/users';
 import { hasProvisionUserRole } from '../src/config/utils';
+import {
+  NPM_ORG,
+  NPM_PACKAGES,
+  PYPI_PROJECTS,
+  getExpectedNpmOrgMembers,
+  getNpmPackageAccess,
+  NPM_DEFAULT_POLICY,
+} from '../src/config/packageAccess';
 
 let passed = 0;
 let failed = 0;
@@ -124,6 +132,46 @@ test('Some members in provisionUser roles have Google user fields', () => {
   return membersInProvisionRoles.length > 0 && provisioned.length > 0;
 });
 
+// Test package registry access config
+test('NPM_ORG is modelcontextprotocol', () => NPM_ORG === 'modelcontextprotocol');
+test('NPM_PACKAGES is not empty and all packages are org-scoped', () =>
+  NPM_PACKAGES.length > 0 && NPM_PACKAGES.every((p) => p.package.startsWith(`@${NPM_ORG}/`)));
+test('All NPM_PACKAGES have at least one maintainer', () =>
+  NPM_PACKAGES.every((p) => p.maintainers.length > 0));
+test('npm usernames on members are unique', () => {
+  const usernames = MEMBERS.filter((m) => m.npm).map((m) => m.npm);
+  return usernames.length === new Set(usernames).size;
+});
+test('pypi usernames on members are unique', () => {
+  const usernames = MEMBERS.filter((m) => m.pypi).map((m) => m.pypi);
+  return usernames.length === new Set(usernames).size;
+});
+test('Expected npm org membership is non-empty, sorted, and unique', () => {
+  const orgMembers = getExpectedNpmOrgMembers();
+  const sorted = [...orgMembers].sort((a, b) => a.localeCompare(b));
+  return (
+    orgMembers.length > 0 &&
+    orgMembers.length === new Set(orgMembers).size &&
+    orgMembers.every((username, i) => username === sorted[i])
+  );
+});
+test('getNpmPackageAccess falls back to the default policy', () => {
+  const access = getNpmPackageAccess(`@${NPM_ORG}/some-undeclared-package`);
+  return access.maintainers === NPM_DEFAULT_POLICY.maintainers && !access.trustedPublisher;
+});
+test('getNpmPackageAccess returns explicit entries', () => {
+  const access = getNpmPackageAccess(`@${NPM_ORG}/sdk`);
+  return !!access.trustedPublisher;
+});
+test('PYPI_PROJECTS includes the mcp project with accounts', () => {
+  const mcp = PYPI_PROJECTS.find((p) => p.project === 'mcp');
+  return !!mcp && mcp.accounts.length > 0;
+});
+test('PyPI project names are unique', () => {
+  const names = PYPI_PROJECTS.map((p) => p.project);
+  return names.length === new Set(names).size;
+});
+
 // Summary
 console.log(`\n${passed} passed, ${failed} failed`);
 process.exit(failed > 0 ? 1 : 0);
diff --git a/scripts/validate-config.ts b/scripts/validate-config.ts
index 1e0c6eb1..b23f1ad5 100644
--- a/scripts/validate-config.ts
+++ b/scripts/validate-config.ts
@@ -7,6 +7,12 @@
 
 import { ROLES, buildRoleLookup } from '../src/config/roles';
 import { REPOSITORY_ACCESS } from '../src/config/repoAccess';
+import {
+  NPM_PACKAGES,
+  PYPI_PROJECTS,
+  UNMAPPED_NPM_USERS,
+  UNMAPPED_PYPI_USERS,
+} from '../src/config/packageAccess';
 import { MEMBERS } from '../src/config/users';
 import { hasProvisionUserRole, resolveGoogleMemberEmail } from '../src/config/utils';
 import type { RoleId } from '../src/config/roleIds';
@@ -193,6 +199,111 @@ for (const member of MEMBERS) {
   }
 }
 
+// Validate npm/PyPI identities and packageAccess.ts references
+console.log('Validating package registry references in packageAccess.ts...');
+{
+  // npm/pypi usernames must be unique across members
+  const npmUsers = new Map<string, string>();
+  const pypiUsers = new Map<string, string>();
+  for (const member of MEMBERS) {
+    const memberId = member.github || member.email || 'unknown';
+    for (const [field, seen] of [
+      ['npm', npmUsers],
+      ['pypi', pypiUsers],
+    ] as const) {
+      const username = member[field];
+      if (!username) continue;
+      const existing = seen.get(username);
+      if (existing) {
+        console.error(
+          `ERROR: ${field} username "${username}" is used by both "${existing}" and "${memberId}"`
+        );
+        hasErrors = true;
+      } else {
+        seen.set(username, memberId);
+      }
+    }
+  }
+
+  // Unmapped lists must not overlap with mapped members (stale entries)
+  for (const username of UNMAPPED_NPM_USERS) {
+    if (npmUsers.has(username)) {
+      console.error(
+        `ERROR: npm username "${username}" is in UNMAPPED_NPM_USERS but is already mapped ` +
+          `to member "${npmUsers.get(username)}" — remove it from the unmapped list`
+      );
+      hasErrors = true;
+    }
+  }
+  for (const username of UNMAPPED_PYPI_USERS) {
+    if (pypiUsers.has(username)) {
+      console.error(
+        `ERROR: PyPI username "${username}" is in UNMAPPED_PYPI_USERS but is already mapped ` +
+          `to member "${pypiUsers.get(username)}" — remove it from the unmapped list`
+      );
+      hasErrors = true;
+    }
+  }
+
+  // Every npm maintainer referenced by a package must be a known account
+  const knownNpm = new Set([...npmUsers.keys(), ...UNMAPPED_NPM_USERS]);
+  const npmPackageNames = new Set<string>();
+  for (const pkg of NPM_PACKAGES) {
+    if (npmPackageNames.has(pkg.package)) {
+      console.error(`ERROR: Package "${pkg.package}" is declared twice in packageAccess.ts`);
+      hasErrors = true;
+    }
+    npmPackageNames.add(pkg.package);
+
+    if (!pkg.package.startsWith('@modelcontextprotocol/')) {
+      console.error(`ERROR: Package "${pkg.package}" is not in the @modelcontextprotocol scope`);
+      hasErrors = true;
+    }
+    for (const username of pkg.maintainers) {
+      if (!knownNpm.has(username)) {
+        console.error(
+          `ERROR: Package "${pkg.package}" references npm user "${username}" which is not ` +
+            `declared on any member in users.ts (npm field) or in UNMAPPED_NPM_USERS`
+        );
+        hasErrors = true;
+      }
+    }
+    if (
+      pkg.trustedPublisher &&
+      !pkg.trustedPublisher.repository.startsWith('modelcontextprotocol/')
+    ) {
+      console.error(
+        `ERROR: Package "${pkg.package}" declares trusted publisher repository ` +
+          `"${pkg.trustedPublisher.repository}" outside the modelcontextprotocol GitHub org`
+      );
+      hasErrors = true;
+    }
+  }
+
+  // Every PyPI account referenced by a project must be a known account
+  const knownPypi = new Set([...pypiUsers.keys(), ...UNMAPPED_PYPI_USERS]);
+  const pypiProjectNames = new Set<string>();
+  for (const project of PYPI_PROJECTS) {
+    if (pypiProjectNames.has(project.project)) {
+      console.error(
+        `ERROR: PyPI project "${project.project}" is declared twice in packageAccess.ts`
+      );
+      hasErrors = true;
+    }
+    pypiProjectNames.add(project.project);
+
+    for (const username of project.accounts) {
+      if (!knownPypi.has(username)) {
+        console.error(
+          `ERROR: PyPI project "${project.project}" references PyPI user "${username}" which is not ` +
+            `declared on any member in users.ts (pypi field) or in UNMAPPED_PYPI_USERS`
+        );
+        hasErrors = true;
+      }
+    }
+  }
+}
+
 // Validate parent role references in roles.ts
 console.log('Validating parent role references in roles.ts...');
 for (const role of ROLES) {
diff --git a/src/config/packageAccess.ts b/src/config/packageAccess.ts
new file mode 100644
index 00000000..3912d3fc
--- /dev/null
+++ b/src/config/packageAccess.ts
@@ -0,0 +1,199 @@
+// npm & PyPI package publishing access configuration
+//
+// This file declares the *expected* state of package-registry access so it can
+// be reviewed and audited in one place. Unlike GitHub/Google/Discord, none of
+// it is applied by Pulumi:
+//
+// - npm: since August 2026 every mutating org/team/package-access/trust
+//   operation requires an interactive 2FA challenge (tokens — even with
+//   "bypass 2FA" — get 403), so unattended reconciliation is impossible.
+//   Read endpoints still work with a granular access token, so drift is
+//   *detected* by scripts/check-package-drift.ts (run weekly by
+//   .github/workflows/package-drift.yml) and *applied* by a human following
+//   the runbook in the README ("npm & PyPI Package Publishing Access").
+// - PyPI: there is no management API at all (collaborators, trusted
+//   publishers and organizations are web-UI only), so the PyPI section below
+//   is declared state for audit plus a manual runbook — nothing is automated.
+//
+// This module must stay import-safe for scripts/validate-config.ts and
+// scripts/test-config.ts: pure data and helpers, no network, no Pulumi.
+
+import { MEMBERS } from './users';
+
+/** The npm organization (scope) that owns @modelcontextprotocol/* packages. */
+export const NPM_ORG = 'modelcontextprotocol';
+
+/**
+ * A package's npm trusted publishing configuration (OIDC from GitHub Actions).
+ * npm allows exactly one trusted publisher per package.
+ */
+export interface NpmTrustedPublisher {
+  /** GitHub repository allowed to publish, as "owner/repo" */
+  repository: string;
+  /** Workflow file path within the repository, e.g. ".github/workflows/main.yml" */
+  workflow: string;
+}
+
+/** Expected access for a single npm package. */
+export interface NpmPackageAccess {
+  /** Full package name, e.g. "@modelcontextprotocol/sdk" */
+  package: string;
+  /**
+   * npm usernames expected to have publish rights (the registry
+   * "maintainers" list). Every entry must be the `npm` field of a member in
+   * users.ts or listed in UNMAPPED_NPM_USERS (enforced by validate-config).
+   */
+  maintainers: readonly string[];
+  /** Expected trusted publishing configuration, if declared */
+  trustedPublisher?: NpmTrustedPublisher;
+}
+
+/**
+ * npm usernames that currently hold access but have not been verifiably
+ * mapped to a member in users.ts yet. Keep this list shrinking: when a
+ * mapping is confirmed, set `npm` on the member and remove the entry here.
+ */
+export const UNMAPPED_NPM_USERS: readonly string[] = [
+  // Registry email ashwin@anthropic.com; no matching entry in users.ts.
+  'ashwin-ant',
+];
+
+/**
+ * The baseline maintainer set for org packages: the npm accounts of the core
+ * publishing group (see users.ts: jspahrsummers, pcarleton, felixweinberger,
+ * dsp-ant, ochafik, plus the unmapped ashwin-ant).
+ */
+export const NPM_BASE_MAINTAINERS: readonly string[] = [
+  'ashwin-ant',
+  'fweinberger',
+  'jspahrsummers',
+  'ochafik-ant',
+  'pcarleton',
+  'thedsp',
+];
+
+/**
+ * Packages with explicitly declared access. Packages in the org that are not
+ * listed here fall under NPM_DEFAULT_POLICY.
+ */
+export const NPM_PACKAGES: readonly NpmPackageAccess[] = [
+  {
+    package: '@modelcontextprotocol/sdk',
+    maintainers: NPM_BASE_MAINTAINERS,
+    trustedPublisher: {
+      repository: 'modelcontextprotocol/typescript-sdk',
+      workflow: '.github/workflows/main.yml',
+    },
+  },
+  {
+    package: '@modelcontextprotocol/inspector',
+    maintainers: [...NPM_BASE_MAINTAINERS, 'cliffhall'],
+    trustedPublisher: {
+      repository: 'modelcontextprotocol/inspector',
+      workflow: '.github/workflows/main.yml',
+    },
+  },
+  {
+    package: '@modelcontextprotocol/server-everything',
+    maintainers: [...NPM_BASE_MAINTAINERS, 'cliffhall'],
+    trustedPublisher: {
+      repository: 'modelcontextprotocol/servers',
+      workflow: '.github/workflows/release.yml',
+    },
+  },
+];
+
+/**
+ * Policy applied to every org package without an explicit NPM_PACKAGES entry
+ * (the org has ~54 packages; the drift checker enumerates them live).
+ */
+export const NPM_DEFAULT_POLICY = {
+  /** Expected maintainers for packages without an explicit entry */
+  maintainers: NPM_BASE_MAINTAINERS,
+  /**
+   * All org packages should publish via trusted publishing (OIDC), not
+   * tokens. The drift checker reports packages whose latest release was not
+   * trusted-published; the exact repository/workflow is only pinned for
+   * packages with an explicit NPM_PACKAGES entry.
+   */
+  requireTrustedPublishing: true,
+} as const;
+
+/** Expected access for the given package: its explicit entry or the default policy. */
+export function getNpmPackageAccess(packageName: string): NpmPackageAccess {
+  return (
+    NPM_PACKAGES.find((p) => p.package === packageName) ?? {
+      package: packageName,
+      maintainers: NPM_DEFAULT_POLICY.maintainers,
+    }
+  );
+}
+
+/**
+ * Expected npm org membership: every npm username declared on a member in
+ * users.ts, plus the not-yet-mapped accounts. Sorted, de-duplicated.
+ */
+export function getExpectedNpmOrgMembers(): string[] {
+  const usernames = new Set<string>(UNMAPPED_NPM_USERS);
+  for (const member of MEMBERS) {
+    if (member.npm) usernames.add(member.npm);
+  }
+  return [...usernames].sort((a, b) => a.localeCompare(b));
+}
+
+// ---------------------------------------------------------------------------
+// PyPI (declared state only — no API exists, nothing is automated)
+// ---------------------------------------------------------------------------
+
+/** Expected access for a single PyPI project. */
+export interface PyPiProjectAccess {
+  /** Project name on pypi.org */
+  project: string;
+  /**
+   * PyPI accounts with a role on the project. PyPI does not publicly expose
+   * whether an account is Owner or Maintainer, so this is a single list.
+   * Every entry must be the `pypi` field of a member in users.ts or listed
+   * in UNMAPPED_PYPI_USERS (enforced by validate-config).
+   */
+  accounts: readonly string[];
+  /** Source repository expected to publish via trusted publishing */
+  repository?: string;
+  /** Caveats about this entry (e.g. unverified rosters) */
+  notes?: string;
+}
+
+/** PyPI usernames with access that are not yet mapped to a member in users.ts. */
+export const UNMAPPED_PYPI_USERS: readonly string[] = [];
+
+export const PYPI_PROJECTS: readonly PyPiProjectAccess[] = [
+  {
+    project: 'mcp',
+    accounts: ['Kludex', 'dsp', 'jspahrsummers', 'maxisbey'],
+    repository: 'modelcontextprotocol/python-sdk',
+  },
+  {
+    project: 'mcp-server-git',
+    accounts: [],
+    repository: 'modelcontextprotocol/servers',
+    notes:
+      'Account roster not yet audited — PyPI exposes rosters only in the ' +
+      'web UI, and this page could not be verified. A project owner should ' +
+      'fill this in from pypi.org/manage/project/mcp-server-git/collaboration/.',
+  },
+  {
+    project: 'mcp-server-fetch',
+    accounts: [],
+    repository: 'modelcontextprotocol/servers',
+    notes:
+      'Account roster not yet audited — see mcp-server-git note; source: ' +
+      'pypi.org/manage/project/mcp-server-fetch/collaboration/.',
+  },
+  {
+    project: 'mcp-server-time',
+    accounts: [],
+    repository: 'modelcontextprotocol/servers',
+    notes:
+      'Account roster not yet audited — see mcp-server-git note; source: ' +
+      'pypi.org/manage/project/mcp-server-time/collaboration/.',
+  },
+];
diff --git a/src/config/users.ts b/src/config/users.ts
index c25e743d..ebd8be4e 100644
--- a/src/config/users.ts
+++ b/src/config/users.ts
@@ -150,6 +150,7 @@ export const MEMBERS: readonly Member[] = [
     github: 'cliffhall',
     email: 'cliff@futurescale.com',
     discord: '501498061965754380',
+    npm: 'cliffhall',
     firstName: 'Cliff',
     lastName: 'Hall',
     googleEmailPrefix: 'cliff',
@@ -240,6 +241,7 @@ export const MEMBERS: readonly Member[] = [
   },
   {
     github: 'dsp',
+    pypi: 'dsp',
     skipGoogleUserProvisioning: true,
     memberOf: [
       ROLE_IDS.AUTH_MAINTAINERS,
@@ -260,6 +262,7 @@ export const MEMBERS: readonly Member[] = [
     github: 'dsp-ant',
     email: 'david@modelcontextprotocol.io',
     discord: '166107790262272000',
+    npm: 'thedsp',
     firstName: 'David',
     lastName: 'Soria Parra',
     googleEmailPrefix: 'david',
@@ -321,6 +324,7 @@ export const MEMBERS: readonly Member[] = [
   {
     github: 'felixweinberger',
     discord: '1377138523492057212',
+    npm: 'fweinberger',
     firstName: 'Felix',
     lastName: 'Weinberger',
     googleEmailPrefix: 'felix',
@@ -434,6 +438,8 @@ export const MEMBERS: readonly Member[] = [
   {
     github: 'jspahrsummers',
     email: 'justin@modelcontextprotocol.io',
+    npm: 'jspahrsummers',
+    pypi: 'jspahrsummers',
     firstName: 'Justin',
     lastName: 'Spahr-Summers',
     googleEmailPrefix: 'justin',
@@ -469,6 +475,7 @@ export const MEMBERS: readonly Member[] = [
   {
     github: 'Kludex',
     discord: '247021664624312322',
+    pypi: 'Kludex',
     firstName: 'Marcelo',
     lastName: 'Trylesinski',
     googleEmailPrefix: 'marcelo',
@@ -569,6 +576,7 @@ export const MEMBERS: readonly Member[] = [
   {
     github: 'maxisbey',
     discord: '1404871241738748058',
+    pypi: 'maxisbey',
     firstName: 'Max',
     lastName: 'Isbey',
     googleEmailPrefix: 'max',
@@ -618,6 +626,7 @@ export const MEMBERS: readonly Member[] = [
   {
     github: 'ochafik',
     discord: '1004897332069925024',
+    npm: 'ochafik-ant',
     firstName: 'Olivier',
     lastName: 'Chafik',
     googleEmailPrefix: 'ochafik',
@@ -661,6 +670,7 @@ export const MEMBERS: readonly Member[] = [
   {
     github: 'pcarleton',
     discord: '1354465170969067852',
+    npm: 'pcarleton',
     firstName: 'Paul',
     lastName: 'Carleton',
     googleEmailPrefix: 'paul',
diff --git a/src/config/utils.ts b/src/config/utils.ts
index f6485967..41784273 100644
--- a/src/config/utils.ts
+++ b/src/config/utils.ts
@@ -13,6 +13,20 @@ export interface Member {
   email?: string;
   /** Discord user ID (snowflake) */
   discord?: string;
+  /**
+   * npm username (npmjs.com). Only set when the mapping to this member has
+   * been verified (e.g. the npm account's registry email matches this member,
+   * or the username is identical and the person is a known maintainer).
+   * Referenced by src/config/packageAccess.ts and
+   * scripts/check-package-drift.ts; not managed by Pulumi.
+   */
+  npm?: string;
+  /**
+   * PyPI username (pypi.org). Only set when the mapping to this member has
+   * been verified. Declared for audit purposes only — PyPI has no management
+   * API, so this is never automated (see packageAccess.ts).
+   */
+  pypi?: string;
   /** Roles this member belongs to */
   memberOf: readonly RoleId[];
   /** First name (required for Google Workspace user provisioning) */