diff --git a/.github/VOUCHED.td b/.github/VOUCHED.td
new file mode 100644
index 000000000..cb9f78b92
--- /dev/null
+++ b/.github/VOUCHED.td
@@ -0,0 +1,27 @@
+# Trust list for this repository.
+#
+# External contributors listed here are treated as trusted by the vouch
+# workflow. Collaborators with write access are automatically trusted and
+# do not need to be duplicated in this file.
+#
+# Syntax:
+#   github:username
+#   -github:username reason for denouncement
+#
+# Keep entries sorted alphabetically.
+github:adityavardhansharma
+github:binbandit
+github:chuks-qua
+github:cursoragent
+github:gbarros-dev
+github:github-actions[bot]
+github:hwanseoc
+github:jamesx0416
+github:jasonLaster
+github:JoeEverest
+github:nmggithub
+github:notkainoa
+github:PatrickBauer
+github:realAhmedRoach
+github:shiroyasha9
+github:Yash-Singh1
diff --git a/.github/workflows/pr-vouch.yml b/.github/workflows/pr-vouch.yml
new file mode 100644
index 000000000..f38c93d44
--- /dev/null
+++ b/.github/workflows/pr-vouch.yml
@@ -0,0 +1,175 @@
+name: PR Vouch
+
+on:
+  pull_request_target:
+    types: [opened, reopened, synchronize, ready_for_review]
+  issue_comment:
+    types: [created]
+  push:
+    branches:
+      - main
+    paths:
+      - .github/VOUCHED.td
+      - .github/workflows/pr-vouch.yml
+
+permissions:
+  contents: read
+  issues: write
+  pull-requests: write
+
+jobs:
+  collect-targets:
+    name: Collect PR targets
+    runs-on: ubuntu-24.04
+    outputs:
+      targets: ${{ steps.collect.outputs.targets }}
+    steps:
+      - id: collect
+        uses: actions/github-script@v7
+        with:
+          script: |
+            if (context.eventName === "pull_request_target") {
+              const pr = context.payload.pull_request;
+              core.setOutput("targets", JSON.stringify([{ number: pr.number, user: pr.user.login }]));
+              return;
+            }
+
+            if (context.eventName === "issue_comment") {
+              const issue = context.payload.issue;
+              const body = context.payload.comment?.body ?? "";
+              if (!issue?.pull_request || !body.includes("/recheck-vouch")) {
+                core.setOutput("targets", "[]");
+                return;
+              }
+
+              core.setOutput(
+                "targets",
+                JSON.stringify([{ number: issue.number, user: issue.user.login }]),
+              );
+              return;
+            }
+
+            const pulls = await github.paginate(github.rest.pulls.list, {
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              state: "open",
+              per_page: 100,
+            });
+
+            const targets = pulls.map((pull) => ({
+              number: pull.number,
+              user: pull.user.login,
+            }));
+            core.setOutput("targets", JSON.stringify(targets));
+
+  label:
+    name: Label PR ${{ matrix.target.number }}
+    needs: collect-targets
+    if: ${{ needs.collect-targets.outputs.targets != '[]' }}
+    runs-on: ubuntu-24.04
+    concurrency:
+      group: pr-vouch-${{ matrix.target.number }}
+      cancel-in-progress: true
+    strategy:
+      fail-fast: false
+      matrix:
+        target: ${{ fromJson(needs.collect-targets.outputs.targets) }}
+    steps:
+      - id: vouch
+        name: Check PR author trust
+        uses: mitchellh/vouch/action/check-user@v1
+        with:
+          user: ${{ matrix.target.user }}
+          allow-fail: true
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Sync PR labels
+        uses: actions/github-script@v7
+        env:
+          PR_NUMBER: ${{ matrix.target.number }}
+          VOUCH_STATUS: ${{ steps.vouch.outputs.status }}
+        with:
+          script: |
+            const issueNumber = Number(process.env.PR_NUMBER);
+            const status = process.env.VOUCH_STATUS;
+            const managedLabels = [
+              {
+                name: "vouch:trusted",
+                color: "1f883d",
+                description: "PR author is trusted by repo permissions or the VOUCHED list.",
+              },
+              {
+                name: "vouch:unvouched",
+                color: "fbca04",
+                description: "PR author is not yet trusted in the VOUCHED list.",
+              },
+              {
+                name: "vouch:denounced",
+                color: "d1242f",
+                description: "PR author is explicitly blocked by the VOUCHED list.",
+              },
+            ];
+
+            const managedLabelNames = managedLabels.map((label) => label.name);
+
+            for (const label of managedLabels) {
+              try {
+                const { data: existing } = await github.rest.issues.getLabel({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  name: label.name,
+                });
+
+                if (
+                  existing.color !== label.color ||
+                  (existing.description ?? "") !== label.description
+                ) {
+                  await github.rest.issues.updateLabel({
+                    owner: context.repo.owner,
+                    repo: context.repo.repo,
+                    name: label.name,
+                    color: label.color,
+                    description: label.description,
+                  });
+                }
+              } catch (error) {
+                if (error.status !== 404) {
+                  throw error;
+                }
+
+                await github.rest.issues.createLabel({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  name: label.name,
+                  color: label.color,
+                  description: label.description,
+                });
+              }
+            }
+
+            const nextLabelName =
+              status === "denounced"
+                ? "vouch:denounced"
+                : ["bot", "collaborator", "vouched"].includes(status)
+                  ? "vouch:trusted"
+                  : "vouch:unvouched";
+
+            const { data: currentLabels } = await github.rest.issues.listLabelsOnIssue({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: issueNumber,
+            });
+
+            const preservedLabels = currentLabels
+              .map((label) => label.name)
+              .filter((name) => !managedLabelNames.includes(name));
+
+            await github.rest.issues.setLabels({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: issueNumber,
+              labels: [...preservedLabels, nextLabelName],
+            });
+
+            core.info(`PR #${issueNumber}: ${status} -> ${nextLabelName}`);
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index fb1992fe7..2021ecdcb 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -8,6 +8,10 @@ You can still open an issue or PR, but please do so knowing there is a high chan
 
 If that sounds annoying, that is because it is. This project is still early and we are trying to keep scope, quality, and direction under control.
 
+PRs are automatically labeled with a `vouch:*` trust status.
+
+If you are an external contributor, expect `vouch:unvouched` until we explicitly add you to [.github/VOUCHED.td](.github/VOUCHED.td).
+
 ## What We Are Most Likely To Accept
 
 Small, focused bug fixes.