diff --git a/.grit/workflows/bun2jest.ts b/.grit/workflows/bun2jest.ts
new file mode 100644
index 000000000..c97ebfded
--- /dev/null
+++ b/.grit/workflows/bun2jest.ts
@@ -0,0 +1,143 @@
+import * as grit from '@getgrit/api';
+import * as sdk from '@getgrit/workflows-sdk';
+
+import { QueryBuilder } from '@getgrit/bridge';
+
+/**
+ * Rewrite a Jest setup file to be usable as a --preload file
+ */
+async function transformTests(targetPath: string) {
+  grit.logging.debug(`Transforming Jest test files at ${targetPath}`);
+  const pattern = `or {
+        js"describe" where { add_import(js"describe", js"'bun:test'")},
+        js"it" where { add_import(js"it", js"'bun:test'")},
+        js"test($_)" where { add_import(js"test", js"'bun:test'")},
+        js"expect($_)" where { add_import(js"expect", js"'bun:test'")},
+}`;
+const query = new QueryBuilder(pattern);
+
+  const instanceCount = await query.run([targetPath]);
+  grit.logging.info(`Transformed Jest setup file at ${targetPath}, with ${instanceCount} changes`);
+
+  return targetPath;
+}
+
+/**
+ * Rewrite a Jest setup file to be usable as a --preload file
+ */
+async function transformSetupFile(targetPath: string) {
+  grit.logging.debug(`Transforming Jest setup file at ${targetPath}`);
+  const pattern = `js"$func($contents)" where {
+    $func <: or {
+        js"beforeAll" => js"beforeEachFile" where { add_import(js"beforeEachFile", js"'bun:test'")},
+        js"afterAll" => js"afterEachFile" where { add_import(js"afterEachFile", js"'bun:test'")},
+    }
+}`;
+const query = new QueryBuilder(pattern);
+
+  const instanceCount = await query.run([targetPath]);
+  grit.logging.info(`Transformed Jest setup file at ${targetPath}, with ${instanceCount} changes`);
+
+  return targetPath;
+}
+
+/**
+ * Fix the provided bun config
+ */
+async function fixBunConfig(targetPath: string, props: { [key: string]: any } = {}) {
+  grit.logging.debug(`Fixing Bun config at ${targetPath}`);
+  const pattern = `
+language toml
+
+file($body) where {
+    // $props = {preload: \`"foo.ts"\`},
+    $props = {${Object.entries(props).map(([key, value]) => `${key}: \`${value}\``).join(', ')}},
+    if ($body <: contains \`[test]
+$existing\`) {
+        $props <: some bubble($existing) [$key, $value] where {
+            or {
+                $existing <: contains \`$key = $_\` => \`$key: $value\`,
+                $existing += \`\n$key = $value\`
+            }
+        }
+    } else {
+        $body += \`\n[test]\n\`,
+        $props <: some bubble($body) [$key, $value] where {
+            $body += \`$key = $value\n\`
+        }
+    }
+}`;
+
+grit.logging.debug(`Pattern: ${pattern}`);
+
+    const query = new QueryBuilder(pattern);
+
+    const instanceCount = await query.run([targetPath]);
+    grit.logging.info(`Fixed Bun config at ${targetPath}, with ${instanceCount} changes`);
+
+    return targetPath;
+}
+
+export default await sdk.defineWorkflow({
+  name: 'jest_to_bun',
+
+  run: async (options) => {
+    const targetDir = process.cwd();
+
+    const configRoot = targetDir;
+
+    // Look for a jest.config.json file
+    const targetFile = 'jest.config.js';
+    const config = await import(`${targetDir}/${targetFile}`);
+
+    grit.logging.debug(`Successfully loaded config`, config);
+
+    // Props we want to set up
+    const props: { [key: string]: string } = {};
+
+    await transformTests(`${configRoot}/src`);
+
+    // Convert from setupFilesAfterEnv -> preload with beforeEachFile
+    if (config.setupFilesAfterEnv) {
+      const preloads = [];
+      for (const setupFile of config.setupFilesAfterEnv) {
+        const actualFile = `${configRoot}/${setupFile}`;
+        const fixed = await transformSetupFile(actualFile);
+        grit.logging.debug(`Adding ${fixed} to preload`);
+        preloads.push(setupFile);
+      }
+      props.preload = JSON.stringify(preloads);
+    }
+
+    if (config.bail) {
+      props.bail = config.bail;
+    }
+
+    if (config.collectCoverage) {
+      props.coverage = config.collectCoverage;
+    }
+
+    if (config.coverageThreshold?.global) {
+      let parts = [];
+      if (config.coverageThreshold.global.lines) {
+        parts.push(`line = ${config.coverageThreshold.global.lines / 100}`);
+      }
+      if (config.coverageThreshold.global.functions) {
+        parts.push(`function = ${config.coverageThreshold.global.functions / 100}`);
+      }
+      if (config.coverageThreshold.global.statements) {
+        parts.push(`statement = ${config.coverageThreshold.global.statements / 100}`);
+      }
+      props.coverageThreshold = `{${parts.join(', ')}}`;
+    }
+
+    // Apply the bunfig
+    const bunConfig = `${configRoot}/Bunfig.toml`;
+    await fixBunConfig(bunConfig, props);
+
+    return {
+      success: true,
+      message: 'Jest to Bun',
+    }
+  },
+});