diff --git a/.github/workflows/publish-js-sdk-canary-scheduler.yaml b/.github/workflows/publish-js-sdk-canary-scheduler.yaml
new file mode 100644
index 00000000..a8f449ec
--- /dev/null
+++ b/.github/workflows/publish-js-sdk-canary-scheduler.yaml
@@ -0,0 +1,47 @@
+# This workflow is responsible for scheduling the JavaScript SDK canary publish workflow on a daily basis.
+# The actual publish workflow is defined in `publish-js-sdk.yaml`, which is triggered by this scheduler workflow.
+# `publish-js-sdk.yaml` has to be where the publish actually happens so that npm trusted publishing still works.
+# npm trusted publishing that only one workflow can publish to npm.
+
+name: Schedule JavaScript SDK Canary Publish
+
+concurrency:
+  group: publish-js-sdk-canary-scheduler
+  cancel-in-progress: false
+
+on:
+  schedule:
+    - cron: "17 6 * * *"
+  workflow_dispatch:
+
+jobs:
+  dispatch-canary-publish:
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    permissions:
+      actions: write
+    steps:
+      - name: Dispatch publish workflow
+        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
+        with:
+          script: |
+            await github.rest.actions.createWorkflowDispatch({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              workflow_id: "publish-js-sdk.yaml",
+              ref: "main",
+              inputs: {
+                release_type: "canary",
+                branch: "main",
+              },
+            });
+
+      - name: Summarize dispatch
+        run: |
+          {
+            echo "## JavaScript SDK Canary Dispatch Queued"
+            echo
+            echo "- Workflow: \`publish-js-sdk.yaml\`"
+            echo "- Release type: \`canary\`"
+            echo "- Branch: \`main\`"
+          } >> "$GITHUB_STEP_SUMMARY"
diff --git a/.github/workflows/publish-js-sdk.yaml b/.github/workflows/publish-js-sdk.yaml
index 883d8280..693f5e61 100644
--- a/.github/workflows/publish-js-sdk.yaml
+++ b/.github/workflows/publish-js-sdk.yaml
@@ -1,7 +1,7 @@
 #
 # This workflow publishes the JavaScript SDK to npm.
 #
-# It supports two manual modes:
+# It supports three modes:
 #
 # 1. STABLE RELEASE:
 #    - Manually triggered via GitHub Actions UI
@@ -15,6 +15,11 @@
 #    - Publishes with the "rc" dist-tag
 #    - Does NOT require updating package.json in the repository
 #
+# 3. CANARY RELEASE:
+#    - Triggered manually or by the canary scheduler workflow
+#    - Publishes with the "canary" dist-tag
+#    - Reuses this workflow file so npm trusted publishing only needs one publisher
+#
 
 name: Publish JavaScript SDK
 
@@ -33,6 +38,7 @@ on:
         options:
           - stable
           - prerelease
+          - canary
       branch:
         description: Branch to release from
         required: true
@@ -46,9 +52,11 @@ jobs:
     outputs:
       version: ${{ steps.release_metadata.outputs.version }}
       is_prerelease: ${{ steps.release_metadata.outputs.is_prerelease }}
+      is_canary: ${{ steps.release_metadata.outputs.is_canary }}
       release_tag: ${{ steps.release_metadata.outputs.release_tag }}
       branch: ${{ steps.release_metadata.outputs.branch }}
       commit: ${{ steps.release_metadata.outputs.commit }}
+      release_type: ${{ steps.release_metadata.outputs.release_type }}
     steps:
       - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
         with:
@@ -57,7 +65,7 @@ jobs:
       - name: Set up Node.js
         uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
         with:
-          node-version: "20"
+          node-version: "22"
       - name: Determine release metadata
         id: release_metadata
         working-directory: js
@@ -69,6 +77,11 @@ jobs:
 
           CURRENT_VERSION=$(node -p "require('./package.json').version")
           RELEASE_COMMIT=$(git rev-parse HEAD)
+          CURRENT_SHA=$(git rev-parse --short=7 HEAD)
+
+          echo "release_type=${RELEASE_TYPE}" >> "$GITHUB_OUTPUT"
+          echo "branch=${TARGET_BRANCH}" >> "$GITHUB_OUTPUT"
+          echo "commit=${RELEASE_COMMIT}" >> "$GITHUB_OUTPUT"
 
           if [[ "$RELEASE_TYPE" == "stable" ]]; then
             RELEASE_TAG="js-sdk-v${CURRENT_VERSION}"
@@ -76,20 +89,27 @@ jobs:
 
             echo "version=${CURRENT_VERSION}" >> "$GITHUB_OUTPUT"
             echo "is_prerelease=false" >> "$GITHUB_OUTPUT"
+            echo "is_canary=false" >> "$GITHUB_OUTPUT"
             echo "release_tag=${RELEASE_TAG}" >> "$GITHUB_OUTPUT"
-          else
+          elif [[ "$RELEASE_TYPE" == "prerelease" ]]; then
             VERSION="${CURRENT_VERSION}-rc.${GITHUB_RUN_NUMBER}"
+
             echo "version=${VERSION}" >> "$GITHUB_OUTPUT"
             echo "is_prerelease=true" >> "$GITHUB_OUTPUT"
+            echo "is_canary=false" >> "$GITHUB_OUTPUT"
             echo "release_tag=" >> "$GITHUB_OUTPUT"
-          fi
+          else
+            VERSION="${CURRENT_VERSION}-canary.$(date -u +%Y%m%d).${GITHUB_RUN_NUMBER}.g${CURRENT_SHA}"
 
-          echo "branch=${TARGET_BRANCH}" >> "$GITHUB_OUTPUT"
-          echo "commit=${RELEASE_COMMIT}" >> "$GITHUB_OUTPUT"
+            echo "version=${VERSION}" >> "$GITHUB_OUTPUT"
+            echo "is_prerelease=false" >> "$GITHUB_OUTPUT"
+            echo "is_canary=true" >> "$GITHUB_OUTPUT"
+            echo "release_tag=" >> "$GITHUB_OUTPUT"
+          fi
 
   build-and-publish-stable:
     needs: prepare-release
-    if: needs.prepare-release.outputs.is_prerelease == 'false'
+    if: needs.prepare-release.outputs.release_type == 'stable'
     runs-on: ubuntu-latest
     timeout-minutes: 20
     permissions:
@@ -109,7 +129,7 @@ jobs:
       - name: Set up Node.js
         uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
         with:
-          node-version: "20"
+          node-version: "22"
           registry-url: "https://registry.npmjs.org"
       - name: Install npm 11.6.2
         run: npm install -g npm@11.6.2
@@ -164,7 +184,7 @@ jobs:
 
   build-and-publish-prerelease:
     needs: prepare-release
-    if: needs.prepare-release.outputs.is_prerelease == 'true'
+    if: needs.prepare-release.outputs.release_type == 'prerelease'
     runs-on: ubuntu-latest
     timeout-minutes: 20
     permissions:
@@ -180,7 +200,7 @@ jobs:
       - name: Set up Node.js
         uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
         with:
-          node-version: "20"
+          node-version: "22"
           registry-url: "https://registry.npmjs.org"
       - name: Install npm 11.6.2
         run: npm install -g npm@11.6.2
@@ -195,20 +215,244 @@ jobs:
           path: js/dist/
           retention-days: 5
 
+  publish-canary:
+    needs: prepare-release
+    if: needs.prepare-release.outputs.release_type == 'canary'
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    outputs:
+      published: ${{ steps.publish_status.outputs.published }}
+      version: ${{ steps.publish_status.outputs.version }}
+      package_name: ${{ steps.publish_status.outputs.package_name }}
+      commit_sha: ${{ steps.publish_status.outputs.commit_sha }}
+      reason: ${{ steps.publish_status.outputs.reason }}
+    permissions:
+      actions: read
+      contents: read
+      id-token: write
+    env:
+      TARGET_BRANCH: ${{ needs.prepare-release.outputs.branch }}
+      VERSION: ${{ needs.prepare-release.outputs.version }}
+    steps:
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
+        with:
+          fetch-depth: 0
+          ref: ${{ needs.prepare-release.outputs.branch }}
+
+      - name: Set up pnpm
+        uses: pnpm/action-setup@b906affcce14559ad1aafd4ab0e942779e9f58b1 # v4.3.0
+
+      - name: Set up Node.js
+        uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
+        with:
+          node-version: "22"
+          cache: "pnpm"
+          registry-url: "https://registry.npmjs.org"
+
+      - name: Install npm 11.6.2
+        run: npm install -g npm@11.6.2
+
+      - name: Check whether a new canary is needed
+        id: should_publish
+        run: |
+          set -euo pipefail
+
+          PACKAGE_NAME="braintrust"
+          CURRENT_SHA=$(git rev-parse --short=7 HEAD)
+          PUBLISHED_VERSION=$(npm view "${PACKAGE_NAME}@canary" version --registry=https://registry.npmjs.org 2>/dev/null || true)
+
+          if [ -z "$PUBLISHED_VERSION" ]; then
+            echo "should_publish=true" >> "$GITHUB_OUTPUT"
+            echo "reason=No existing canary found on npm." >> "$GITHUB_OUTPUT"
+            echo "previous_version=" >> "$GITHUB_OUTPUT"
+            echo "previous_sha=" >> "$GITHUB_OUTPUT"
+            exit 0
+          fi
+
+          PUBLISHED_SHA=$(printf '%s\n' "$PUBLISHED_VERSION" | sed -n 's/.*\.g\([0-9a-f]\{7\}\)$/\1/p')
+          echo "previous_version=${PUBLISHED_VERSION}" >> "$GITHUB_OUTPUT"
+          echo "previous_sha=${PUBLISHED_SHA}" >> "$GITHUB_OUTPUT"
+
+          if [ "$PUBLISHED_SHA" = "$CURRENT_SHA" ]; then
+            echo "should_publish=false" >> "$GITHUB_OUTPUT"
+            echo "reason=Current HEAD ${CURRENT_SHA} is already published as canary ${PUBLISHED_VERSION}." >> "$GITHUB_OUTPUT"
+          else
+            echo "should_publish=true" >> "$GITHUB_OUTPUT"
+            echo "reason=Published canary ${PUBLISHED_VERSION} does not match HEAD ${CURRENT_SHA}." >> "$GITHUB_OUTPUT"
+          fi
+
+      - name: Check JS CI status
+        if: steps.should_publish.outputs.should_publish == 'true'
+        id: ci_status
+        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
+        env:
+          TARGET_BRANCH: ${{ env.TARGET_BRANCH }}
+        with:
+          script: |
+            const { owner, repo } = context.repo;
+            const response = await github.rest.actions.listWorkflowRuns({
+              owner,
+              repo,
+              workflow_id: "js.yaml",
+              branch: process.env.TARGET_BRANCH,
+              status: "completed",
+              per_page: 1,
+            });
+
+            const run = response.data.workflow_runs[0];
+            if (!run) {
+              core.setOutput("should_publish", "false");
+              core.setOutput("reason", `No completed js.yaml run found on ${process.env.TARGET_BRANCH}.`);
+              return;
+            }
+
+            if (run.conclusion !== "success") {
+              core.setOutput("should_publish", "false");
+              core.setOutput(
+                "reason",
+                `Latest completed js.yaml run on ${process.env.TARGET_BRANCH} concluded with ${run.conclusion} (${run.html_url}).`,
+              );
+              return;
+            }
+
+            core.setOutput("should_publish", "true");
+            core.setOutput(
+              "reason",
+              `Latest completed js.yaml run on ${process.env.TARGET_BRANCH} succeeded (${run.html_url}).`,
+            );
+
+      - name: Install dependencies
+        if: steps.should_publish.outputs.should_publish == 'true' && steps.ci_status.outputs.should_publish == 'true'
+        run: pnpm install --frozen-lockfile
+
+      - name: Prepare canary package metadata
+        if: steps.should_publish.outputs.should_publish == 'true' && steps.ci_status.outputs.should_publish == 'true'
+        id: metadata
+        working-directory: js
+        env:
+          VERSION: ${{ env.VERSION }}
+        run: |
+          set -euo pipefail
+
+          CURRENT_SHA=$(git rev-parse --short=7 HEAD)
+          CANARY_NAME="braintrust"
+          npm version "$VERSION" --no-git-tag-version --allow-same-version
+
+          echo "version=${VERSION}" >> "$GITHUB_OUTPUT"
+          echo "package_name=${CANARY_NAME}" >> "$GITHUB_OUTPUT"
+          echo "commit_sha=${CURRENT_SHA}" >> "$GITHUB_OUTPUT"
+
+      - name: Build SDK
+        if: steps.should_publish.outputs.should_publish == 'true' && steps.ci_status.outputs.should_publish == 'true'
+        working-directory: js
+        run: pnpm run build
+
+      - name: Publish canary to npm
+        if: steps.should_publish.outputs.should_publish == 'true' && steps.ci_status.outputs.should_publish == 'true'
+        working-directory: js
+        run: npm publish --tag canary
+
+      - name: Upload build artifacts
+        if: steps.should_publish.outputs.should_publish == 'true' && steps.ci_status.outputs.should_publish == 'true'
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        with:
+          name: javascript-sdk-canary-dist
+          path: js/dist/
+          retention-days: 5
+
+      - name: Summarize canary publish
+        if: steps.should_publish.outputs.should_publish == 'true' && steps.ci_status.outputs.should_publish == 'true'
+        env:
+          PACKAGE_NAME: ${{ steps.metadata.outputs.package_name }}
+          VERSION: ${{ steps.metadata.outputs.version }}
+          COMMIT_SHA: ${{ steps.metadata.outputs.commit_sha }}
+          PREVIOUS_VERSION: ${{ steps.should_publish.outputs.previous_version }}
+          PREVIOUS_SHA: ${{ steps.should_publish.outputs.previous_sha }}
+        run: |
+          set -euo pipefail
+
+          {
+            echo "## JavaScript SDK Canary Published"
+            echo
+            echo "- Package: \`${PACKAGE_NAME}\`"
+            echo "- Version: \`${VERSION}\`"
+            echo "- Commit: \`${COMMIT_SHA}\`"
+            echo "- Registry: \`https://registry.npmjs.org\`"
+            echo "- Install: \`npm install ${PACKAGE_NAME}@canary\`"
+            echo
+            echo "### Included commits"
+            if [ -n "$PREVIOUS_SHA" ]; then
+              echo "- Previous canary: \`${PREVIOUS_VERSION}\`"
+              git log "${PREVIOUS_SHA}..HEAD" --pretty=format:"- %h %s (%an)"
+            else
+              echo "- Previous canary: none"
+              git log -n 20 --pretty=format:"- %h %s (%an)"
+            fi
+          } >> "$GITHUB_STEP_SUMMARY"
+
+      - name: Summarize skipped canary publish
+        if: steps.should_publish.outputs.should_publish != 'true' || steps.ci_status.outputs.should_publish != 'true'
+        env:
+          SHOULD_PUBLISH_REASON: ${{ steps.should_publish.outputs.reason }}
+          CI_REASON: ${{ steps.ci_status.outputs.reason }}
+        run: |
+          set -euo pipefail
+
+          REASON="${CI_REASON:-$SHOULD_PUBLISH_REASON}"
+
+          {
+            echo "## JavaScript SDK Canary Skipped"
+            echo
+            echo "$REASON"
+          } >> "$GITHUB_STEP_SUMMARY"
+
+      - name: Set publish status outputs
+        id: publish_status
+        if: always()
+        env:
+          SHOULD_PUBLISH: ${{ steps.should_publish.outputs.should_publish }}
+          CI_SHOULD_PUBLISH: ${{ steps.ci_status.outputs.should_publish }}
+          VERSION: ${{ steps.metadata.outputs.version }}
+          PACKAGE_NAME: ${{ steps.metadata.outputs.package_name }}
+          COMMIT_SHA: ${{ steps.metadata.outputs.commit_sha }}
+          SHOULD_PUBLISH_REASON: ${{ steps.should_publish.outputs.reason }}
+          CI_REASON: ${{ steps.ci_status.outputs.reason }}
+        run: |
+          set -euo pipefail
+
+          if [ "${SHOULD_PUBLISH}" = "true" ] && [ "${CI_SHOULD_PUBLISH}" = "true" ]; then
+            echo "published=true" >> "$GITHUB_OUTPUT"
+          else
+            echo "published=false" >> "$GITHUB_OUTPUT"
+          fi
+
+          REASON="${CI_REASON:-$SHOULD_PUBLISH_REASON}"
+
+          echo "version=${VERSION}" >> "$GITHUB_OUTPUT"
+          echo "package_name=${PACKAGE_NAME}" >> "$GITHUB_OUTPUT"
+          echo "commit_sha=${COMMIT_SHA}" >> "$GITHUB_OUTPUT"
+          echo "reason=${REASON}" >> "$GITHUB_OUTPUT"
+
   notify-success:
     needs:
-      [prepare-release, build-and-publish-stable, build-and-publish-prerelease]
+      [
+        prepare-release,
+        build-and-publish-stable,
+        build-and-publish-prerelease,
+        publish-canary,
+      ]
     if: |
       always() &&
       (
         needs.build-and-publish-stable.result == 'success' ||
-        needs.build-and-publish-prerelease.result == 'success'
+        needs.build-and-publish-prerelease.result == 'success' ||
+        (needs.publish-canary.result == 'success' && needs.publish-canary.outputs.published == 'true')
       )
     runs-on: ubuntu-latest
     timeout-minutes: 5
     steps:
       - name: Post to Slack on success (stable release)
-        if: needs.prepare-release.outputs.is_prerelease == 'false'
+        if: needs.prepare-release.outputs.release_type == 'stable'
         uses: slackapi/slack-github-action@91efab103c0de0a537f72a35f6b8cda0ee76bf0a # v2.1.1
         with:
           method: chat.postMessage
@@ -225,8 +469,9 @@ jobs:
                 text:
                   type: "mrkdwn"
                   text: "*Version:* ${{ needs.prepare-release.outputs.version }}\n*Branch:* `${{ needs.prepare-release.outputs.branch }}`\n*Package:* <https://www.npmjs.com/package/braintrust|braintrust>\n\n<${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}|View Run>"
+
       - name: Post to Slack on success (pre-release)
-        if: needs.prepare-release.outputs.is_prerelease == 'true'
+        if: needs.prepare-release.outputs.release_type == 'prerelease'
         uses: slackapi/slack-github-action@91efab103c0de0a537f72a35f6b8cda0ee76bf0a # v2.1.1
         with:
           method: chat.postMessage
@@ -244,15 +489,40 @@ jobs:
                   type: "mrkdwn"
                   text: "*Version:* ${{ needs.prepare-release.outputs.version }}\n*Branch:* `${{ needs.prepare-release.outputs.branch }}`\n*npm tag:* `rc` (install with `npm install braintrust@rc`)\n*Package:* <https://www.npmjs.com/package/braintrust|braintrust>\n\n<${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}|View Run>"
 
+      - name: Post to Slack on success (canary)
+        if: needs.prepare-release.outputs.release_type == 'canary'
+        uses: slackapi/slack-github-action@91efab103c0de0a537f72a35f6b8cda0ee76bf0a # v2.1.1
+        with:
+          method: chat.postMessage
+          token: ${{ secrets.SLACK_BOT_TOKEN }}
+          payload: |
+            channel: C0ABHT0SWA2
+            text: "🧪 JavaScript SDK canary ${{ needs.publish-canary.outputs.version }} published: https://www.npmjs.com/package/braintrust/v/${{ needs.publish-canary.outputs.version }}"
+            blocks:
+              - type: "header"
+                text:
+                  type: "plain_text"
+                  text: "🧪 JavaScript SDK Canary Published"
+              - type: "section"
+                text:
+                  type: "mrkdwn"
+                  text: "*Version:* ${{ needs.publish-canary.outputs.version }}\n*Branch:* `${{ needs.prepare-release.outputs.branch }}`\n*Commit:* `${{ needs.publish-canary.outputs.commit_sha }}`\n*Package:* <https://www.npmjs.com/package/braintrust/v/${{ needs.publish-canary.outputs.version }}|${{ needs.publish-canary.outputs.package_name }}>\n*Install:* `npm install ${{ needs.publish-canary.outputs.package_name }}@canary`\n\n<${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}|View Run>"
+
   notify-failure:
     needs:
-      [prepare-release, build-and-publish-stable, build-and-publish-prerelease]
+      [
+        prepare-release,
+        build-and-publish-stable,
+        build-and-publish-prerelease,
+        publish-canary,
+      ]
     if: |
       always() &&
       (
         needs.prepare-release.result == 'failure' ||
         needs.build-and-publish-stable.result == 'failure' ||
-        needs.build-and-publish-prerelease.result == 'failure'
+        needs.build-and-publish-prerelease.result == 'failure' ||
+        needs.publish-canary.result == 'failure'
       )
     runs-on: ubuntu-latest
     timeout-minutes: 5
@@ -273,4 +543,32 @@ jobs:
               - type: "section"
                 text:
                   type: "mrkdwn"
-                  text: "*Release type:* ${{ inputs.release_type }}\n*Branch:* `${{ inputs.branch }}`\n*Commit:* ${{ needs.prepare-release.outputs.commit || github.sha }}\n*Triggered by:* ${{ github.event_name }}\n\n<${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}|View Run>"
+                  text: "*Release type:* ${{ needs.prepare-release.outputs.release_type || 'canary' }}\n*Branch:* `${{ needs.prepare-release.outputs.branch || 'main' }}`\n*Commit:* ${{ needs.prepare-release.outputs.commit || github.sha }}\n*Triggered by:* ${{ github.event_name }}\n\n<${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}|View Run>"
+
+  notify-skipped:
+    needs: [prepare-release, publish-canary]
+    if: |
+      always() &&
+      needs.prepare-release.outputs.release_type == 'canary' &&
+      needs.publish-canary.result == 'success' &&
+      needs.publish-canary.outputs.published != 'true'
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - name: Post to Slack on intentional skip
+        uses: slackapi/slack-github-action@91efab103c0de0a537f72a35f6b8cda0ee76bf0a # v2.1.1
+        with:
+          method: chat.postMessage
+          token: ${{ secrets.SLACK_BOT_TOKEN }}
+          payload: |
+            channel: C0ABHT0SWA2
+            text: "⏭️ JavaScript SDK canary publish skipped: ${{ needs.publish-canary.outputs.reason }}"
+            blocks:
+              - type: "header"
+                text:
+                  type: "plain_text"
+                  text: "⏭️ JavaScript SDK Canary Publish Skipped"
+              - type: "section"
+                text:
+                  type: "mrkdwn"
+                  text: "*Branch:* `${{ needs.prepare-release.outputs.branch }}`\n*Commit:* `${{ needs.prepare-release.outputs.commit }}`\n*Reason:* ${{ needs.publish-canary.outputs.reason }}\n\n<${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}|View Run>"
diff --git a/Makefile b/Makefile
index cc49249f..076312b6 100644
--- a/Makefile
+++ b/Makefile
@@ -62,7 +62,7 @@ js-test-otel-docker:
 # -------------------------------------------------------------------------------------------------
 # Stable release publishing
 # Preferred: trigger publish-js-sdk.yaml from GitHub Actions UI
-# Fallback: make release-js-sdk [BRANCH=<branch>] dispatches the same workflow via gh
+# Fallback: make release-js-sdk [RELEASE_TYPE=stable|prerelease|canary] [BRANCH=<branch>] dispatches the same workflow via gh
 # -------------------------------------------------------------------------------------------------
 .PHONY: release-js-sdk
 
diff --git a/PUBLISHING_JS.md b/PUBLISHING_JS.md
index ec6df106..afb4f44a 100644
--- a/PUBLISHING_JS.md
+++ b/PUBLISHING_JS.md
@@ -4,7 +4,9 @@
 
 Use the [Publish JavaScript SDK workflow](https://github.com/braintrustdata/braintrust-sdk-javascript/actions/workflows/publish-js-sdk.yaml) in GitHub Actions.
 
-This is the primary release entrypoint for both stable releases and prereleases.
+This is the single npm publish entrypoint for stable releases, prereleases, and canaries.
+
+We keep all npm publishes in one workflow file because npm trusted publishing only allows one configured GitHub Actions publisher per package.
 
 Stable releases now pause at the `npm-publish` GitHub Actions environment and require approval before the publish job runs.
 
@@ -25,6 +27,15 @@ Stable releases now pause at the `npm-publish` GitHub Actions environment and re
 - Publishes to the `rc` npm dist-tag
 - Does not update `js/package.json` in the repository
 
+### Canary
+
+- Can be triggered manually by running the same workflow with `release_type=canary`
+- Publishes `<js/package.json version>-canary.<YYYYMMDD>.<run_number>.g<short_sha>`
+- Publishes to the `canary` npm dist-tag
+- Does not create a GitHub release
+- Skips publishing if the current `HEAD` commit already matches the existing `canary` tag on npm
+- Skips publishing unless the latest completed `js.yaml` run on the target branch succeeded
+
 ## Stable Release Checklist
 
 1. Bump `js/package.json` according to [SEMVER](https://semver.org/) principles.
@@ -51,6 +62,17 @@ Stable releases now pause at the `npm-publish` GitHub Actions environment and re
 
 If you prerelease from a non-`main` branch, make sure that branch is in the state you intend to publish.
 
+## Nightly Canary
+
+Nightly canary scheduling now lives in the separate [Schedule JavaScript SDK Canary Publish workflow](https://github.com/braintrustdata/braintrust-sdk-javascript/actions/workflows/publish-js-sdk-canary-scheduler.yaml).
+
+- The scheduler only dispatches [Publish JavaScript SDK](https://github.com/braintrustdata/braintrust-sdk-javascript/actions/workflows/publish-js-sdk.yaml) with `release_type=canary` and `branch=main`.
+- The actual npm publish still runs in `publish-js-sdk.yaml`, so npm trusted publishing only needs that one workflow configured as the publisher.
+- Manual canary runs still use the publish workflow dispatch form directly.
+- Install with `npm install braintrust@canary`.
+
+The workflow writes a short run summary with the published version and recent commits touching `js/` so there is at least a lightweight change summary even though there is no formal changelog.
+
 ## Fallback CLI Trigger
 
 If you do not want to open GitHub Actions manually, you can dispatch the same workflow from the terminal:
@@ -65,12 +87,20 @@ To target a different remote branch:
 make release-js-sdk BRANCH=<branch>
 ```
 
+To dispatch a prerelease or canary instead of a stable release:
+
+```bash
+make release-js-sdk RELEASE_TYPE=prerelease
+make release-js-sdk RELEASE_TYPE=canary
+```
+
 Notes:
 
 - This is a fallback, not the recommended path.
 - It requires `gh` to be installed and authenticated.
 - It does not publish from your local checkout.
 - It dispatches the same GitHub Actions workflow against the selected branch on GitHub.
+- `RELEASE_TYPE` defaults to `stable`.
 
 ## Repository Setup
 
diff --git a/js/scripts/dispatch-release-workflow.sh b/js/scripts/dispatch-release-workflow.sh
index 9e5d9633..c814ef0b 100755
--- a/js/scripts/dispatch-release-workflow.sh
+++ b/js/scripts/dispatch-release-workflow.sh
@@ -15,6 +15,16 @@ if ! gh auth status >/dev/null 2>&1; then
 fi
 
 BRANCH="${BRANCH:-$(git rev-parse --abbrev-ref HEAD)}"
+RELEASE_TYPE="${RELEASE_TYPE:-stable}"
+
+case "$RELEASE_TYPE" in
+  stable|prerelease|canary)
+    ;;
+  *)
+    echo "ERROR: RELEASE_TYPE must be one of: stable, prerelease, canary"
+    exit 1
+    ;;
+esac
 
 if [ "$BRANCH" = "HEAD" ]; then
   echo "ERROR: Could not determine the current branch. Set BRANCH=<branch> and retry."
@@ -26,7 +36,7 @@ if ! git ls-remote --exit-code --heads origin "$BRANCH" >/dev/null 2>&1; then
   exit 1
 fi
 
-echo "Dispatching publish-js-sdk workflow for branch '$BRANCH'..."
-gh workflow run publish-js-sdk.yaml --ref "$BRANCH" -f release_type=stable -f branch="$BRANCH"
+echo "Dispatching publish-js-sdk workflow for branch '$BRANCH' with release_type='$RELEASE_TYPE'..."
+gh workflow run publish-js-sdk.yaml --ref "$BRANCH" -f release_type="$RELEASE_TYPE" -f branch="$BRANCH"
 echo "Workflow dispatched:"
 echo "https://github.com/braintrustdata/braintrust-sdk-javascript/actions/workflows/publish-js-sdk.yaml"