diff --git a/.opencode/index.ts b/.opencode/index.ts
index fa6cadc58..8ee800f80 100644
--- a/.opencode/index.ts
+++ b/.opencode/index.ts
@@ -37,4 +37,4 @@
 // Export the main plugin
 // opencode's legacy plugin loader iterates every module export and throws if
 // any is not a plugin function, so only the plugin function may be exported.
-export { default } from "./plugins/index.js"
+export { default } from "./plugins/index.ts"
diff --git a/.opencode/plugins/ecc-hooks.ts b/.opencode/plugins/ecc-hooks.ts
index 22b1132f0..69b59727e 100644
--- a/.opencode/plugins/ecc-hooks.ts
+++ b/.opencode/plugins/ecc-hooks.ts
@@ -16,8 +16,8 @@
 import type { PluginInput } from "@opencode-ai/plugin"
 import * as fs from "fs"
 import * as path from "path"
-import changedFilesTool from "../tools/changed-files.js"
-import dependencyAnalyzerTool from "../tools/dependency-analyzer.js"
+import changedFilesTool from "../tools/changed-files.ts"
+import dependencyAnalyzerTool from "../tools/dependency-analyzer.ts"
 
 /**
  * Type definitions for better type safety
@@ -111,9 +111,9 @@ export const ECCHooksPlugin: ECCHooksPluginFn = async ({
   // This plugin is OpenCode's startup entry point, so a static import
   // failure here previously crashed the whole plugin -- and with it, the
   // entire OpenCode session -- before any hooks could load (see #2530).
-  let changedFilesStore: typeof import("./lib/changed-files-store.js") | undefined
+  let changedFilesStore: typeof import("./lib/changed-files-store.ts") | undefined
   try {
-    const store = await import("./lib/changed-files-store.js")
+    const store = await import("./lib/changed-files-store.ts")
     store.initStore(worktreePath)
     changedFilesStore = store
   } catch {
diff --git a/.opencode/plugins/index.ts b/.opencode/plugins/index.ts
index c1e17a159..3a98f0ba6 100644
--- a/.opencode/plugins/index.ts
+++ b/.opencode/plugins/index.ts
@@ -6,7 +6,7 @@
  * while taking advantage of OpenCode's more sophisticated 20+ event types.
  */
 
-export { ECCHooksPlugin, default } from "./ecc-hooks.js"
+export { ECCHooksPlugin, default } from "./ecc-hooks.ts"
 
 // Re-export for named imports
-export * from "./ecc-hooks.js"
+export * from "./ecc-hooks.ts"
diff --git a/.opencode/tools/changed-files.ts b/.opencode/tools/changed-files.ts
index 1150ca756..3ae000e1b 100644
--- a/.opencode/tools/changed-files.ts
+++ b/.opencode/tools/changed-files.ts
@@ -1,5 +1,5 @@
 import { tool, type ToolDefinition } from "@opencode-ai/plugin/tool"
-import type { ChangeType, TreeNode } from "../plugins/lib/changed-files-store.js"
+import type { ChangeType, TreeNode } from "../plugins/lib/changed-files-store.ts"
 
 const INDICATORS: Record<ChangeType, string> = {
   added: "+",
@@ -27,12 +27,12 @@ function renderTree(nodes: TreeNode[], indent: string): string {
 // file, so a static import failure here previously took down the entire
 // tools module -- and with it, the whole OpenCode session -- on the very
 // first tool-loading pass (see #2530).
-type ChangedFilesStore = typeof import("../plugins/lib/changed-files-store.js")
+type ChangedFilesStore = typeof import("../plugins/lib/changed-files-store.ts")
 let changedFilesStorePromise: Promise<ChangedFilesStore> | undefined
 
 async function loadChangedFilesStore(): Promise<ChangedFilesStore> {
   if (!changedFilesStorePromise) {
-    changedFilesStorePromise = import("../plugins/lib/changed-files-store.js").catch(() => {
+    changedFilesStorePromise = import("../plugins/lib/changed-files-store.ts").catch(() => {
       changedFilesStorePromise = undefined
       throw new Error(
         "changed-files tool: could not load the changed-files store. " +
diff --git a/.opencode/tools/index.ts b/.opencode/tools/index.ts
index 9bd999479..17db1081a 100644
--- a/.opencode/tools/index.ts
+++ b/.opencode/tools/index.ts
@@ -5,11 +5,11 @@
  */
 
 // Re-export all tools
-export { default as runTests } from "./run-tests.js"
-export { default as checkCoverage } from "./check-coverage.js"
-export { default as securityAudit } from "./security-audit.js"
-export { default as formatCode } from "./format-code.js"
-export { default as lintCheck } from "./lint-check.js"
-export { default as gitSummary } from "./git-summary.js"
-export { default as changedFiles } from "./changed-files.js"
-export { default as dependencyAnalyzer } from "./dependency-analyzer.js"
+export { default as runTests } from "./run-tests.ts"
+export { default as checkCoverage } from "./check-coverage.ts"
+export { default as securityAudit } from "./security-audit.ts"
+export { default as formatCode } from "./format-code.ts"
+export { default as lintCheck } from "./lint-check.ts"
+export { default as gitSummary } from "./git-summary.ts"
+export { default as changedFiles } from "./changed-files.ts"
+export { default as dependencyAnalyzer } from "./dependency-analyzer.ts"
diff --git a/.opencode/tsconfig.json b/.opencode/tsconfig.json
index c6b43257b..1d586042f 100644
--- a/.opencode/tsconfig.json
+++ b/.opencode/tsconfig.json
@@ -15,7 +15,8 @@
     "sourceMap": true,
     "resolveJsonModule": true,
     "isolatedModules": true,
-    "verbatimModuleSyntax": true,
+    "allowImportingTsExtensions": true,
+    "rewriteRelativeImportExtensions": true,
     "types": ["node"]
   },
   "include": [
diff --git a/package.json b/package.json
index 839f94081..70a31ff8d 100644
--- a/package.json
+++ b/package.json
@@ -2,6 +2,17 @@
   "name": "ecc-universal",
   "version": "2.2.1",
   "description": "Harness-native agent operating system for Codex, OpenCode, Cursor, Gemini, Claude Code, and terminal workflows - skills, hooks, rules, MCP conventions, and operator control-plane patterns",
+  "main": ".opencode/dist/index.js",
+  "types": ".opencode/dist/index.d.ts",
+  "exports": {
+    ".": {
+      "types": "./.opencode/dist/index.d.ts",
+      "import": "./.opencode/dist/index.js",
+      "default": "./.opencode/dist/index.js"
+    },
+    "./package.json": "./package.json",
+    "./*": "./*"
+  },
   "publishConfig": {
     "access": "public"
   },
diff --git a/tests/scripts/build-opencode.test.js b/tests/scripts/build-opencode.test.js
index 469165883..b8743b3e0 100644
--- a/tests/scripts/build-opencode.test.js
+++ b/tests/scripts/build-opencode.test.js
@@ -4,6 +4,7 @@
 
 const assert = require("assert")
 const fs = require("fs")
+const os = require("os")
 const path = require("path")
 const { spawnSync } = require("child_process")
 const { getNpmPackEntry } = require("../lib/npm-pack-output")
@@ -46,6 +47,72 @@ function main() {
       assert.strictEqual(result.status, 0, result.stderr)
       assert.ok(fs.existsSync(distEntry), ".opencode/dist/index.js should exist after build")
     }],
+    ["package.json declares a resolvable OpenCode plugin entry", () => {
+      assert.strictEqual(packageJson.main, ".opencode/dist/index.js")
+      assert.ok(packageJson.exports, "package.json must declare an exports map")
+      assert.deepStrictEqual(packageJson.exports["."], {
+        types: "./.opencode/dist/index.d.ts",
+        import: "./.opencode/dist/index.js",
+        default: "./.opencode/dist/index.js",
+      })
+    }],
+    ["installed package resolves and imports its root module by name", () => {
+      const tempDir = fs.mkdtempSync(path.join(os.tmpdir(), "ecc-opencode-entry-"))
+      try {
+        fs.mkdirSync(path.join(tempDir, "node_modules"), { recursive: true })
+        fs.symlinkSync(
+          repoRoot,
+          path.join(tempDir, "node_modules", "ecc-universal"),
+          process.platform === "win32" ? "junction" : "dir"
+        )
+        const probe = `
+          const resolved = import.meta.resolve("ecc-universal")
+          if (!resolved.endsWith("/.opencode/dist/index.js")) {
+            throw new Error("unexpected entry resolution: " + resolved)
+          }
+          const mod = await import("ecc-universal")
+          if (Object.keys(mod).join(",") !== "default" || typeof mod.default !== "function") {
+            throw new Error("root module must export exactly the plugin function")
+          }
+        `
+        const probePath = path.join(tempDir, "probe.mjs")
+        fs.writeFileSync(probePath, probe)
+        const result = spawnSync(process.execPath, [probePath], {
+          cwd: tempDir,
+          encoding: "utf8",
+        })
+        assert.strictEqual(result.status, 0, result.stderr)
+      } finally {
+        fs.rmSync(tempDir, { recursive: true, force: true })
+      }
+    }],
+    ["OpenCode TypeScript sources resolve their relative imports in place", () => {
+      const opencodeDir = path.join(repoRoot, ".opencode")
+      const sourceFiles = []
+      const walk = (dir) => {
+        for (const entry of fs.readdirSync(dir, { withFileTypes: true })) {
+          const entryPath = path.join(dir, entry.name)
+          if (entry.isDirectory()) {
+            if (entry.name !== "node_modules" && entry.name !== "dist") walk(entryPath)
+          } else if (entry.name.endsWith(".ts")) {
+            sourceFiles.push(entryPath)
+          }
+        }
+      }
+      walk(opencodeDir)
+      assert.ok(sourceFiles.length > 0, "expected OpenCode TypeScript sources")
+      const unresolved = []
+      for (const sourceFile of sourceFiles) {
+        const source = fs.readFileSync(sourceFile, "utf8")
+        for (const match of source.matchAll(/(?:from|import)\s*\(?\s*"(\.[^"]+)"/g)) {
+          const target = path.resolve(path.dirname(sourceFile), match[1])
+          if (!fs.existsSync(target)) {
+            unresolved.push(`${path.relative(repoRoot, sourceFile)} -> ${match[1]}`)
+          }
+        }
+      }
+      assert.deepStrictEqual(unresolved, [])
+    }],
     ["built OpenCode entry exports only the plugin function", () => {
       const check = `
         const assert = require("assert")