diff --git a/README.md b/README.md
index 0007a48..48d856c 100644
--- a/README.md
+++ b/README.md
@@ -89,6 +89,8 @@ Load errors: `~/.local/share/opencode/log/` (search `cache-hit` or `failed to lo
 
 ## Configuration
 
+Configuration files accept JSONC (line/block comments and trailing commas). `cache-hit.config.example.json` ships as strict JSON so it stays tool-friendly (jq, editors).
+
 ### Cost display (USD → CNY example)
 
 ```json
@@ -105,7 +107,7 @@ Load errors: `~/.local/share/opencode/log/` (search `cache-hit` or `failed to lo
 | `currency` | Sidebar display currency |
 | `rate` | Multiply `costUnit` → `currency` |
 
-Use `"currency": "USD", "costUnit": "USD"` when no conversion is needed.
+`rate` is a **manual snapshot** — the `6.77` in the example is the USD→CNY rate at the time it was written and does not auto-update. Omitting `rate` falls back to the same built-in default, so it only needs to be set when you display a non-USD currency and want a current rate (e.g. from [Xe](https://www.xe.com/currencyconverter/), [Wise](https://wise.com/currency-converter), or [OANDA](https://www.oanda.com/currency-converter/)). Use `"currency": "USD", "costUnit": "USD"` when no conversion is needed.
 
 Supported display currencies in config: `USD`, `CNY`, `EUR`, `GBP`, `JPY` (see `cache-hit.config.example.json`). Runtime slash switching like visual-cache’s `/cache-currency` is **not** implemented yet.
 
@@ -271,7 +273,7 @@ Then reinstall via `Ctrl+P` → install plugin, and **restart OpenCode**.
 To avoid the pinning issue entirely, install a **pinned version** instead of `@latest`:
 
 ```jsonc
-{ "plugin": ["opencode-cache-hit@0.7.0"] }
+{ "plugin": ["opencode-cache-hit@0.7.1"] }
 ```
 
 ## Compatibility
diff --git a/README.zh-CN.md b/README.zh-CN.md
index 68bc8d6..8799132 100644
--- a/README.zh-CN.md
+++ b/README.zh-CN.md
@@ -89,6 +89,8 @@ OpenCode **TUI 侧边栏插件**：展示 prompt cache 命中率、token 用量
 
 ## 配置
 
+配置文件支持 JSONC（行注释、块注释、尾逗号）。`cache-hit.config.example.json` 保持严格 JSON，便于 jq、编辑器等外部工具使用。
+
 ### 成本展示（USD → CNY 示例）
 
 ```json
@@ -105,7 +107,7 @@ OpenCode **TUI 侧边栏插件**：展示 prompt cache 命中率、token 用量
 | `currency` | 侧边栏展示币种 |
 | `rate` | `costUnit` → `currency` 的汇率 |
 
-当无需换算时使用 `"currency": "USD", "costUnit": "USD"`。
+`rate` 是**手动维护的快照值**——示例中的 `6.77` 是当时 USD→CNY 的汇率，不会自动更新。省略 `rate` 时回落到内置默认值 6.77，因此只有在展示非 USD 币种且希望汇率准确时才需要设置（可到 [Xe](https://www.xe.com/currencyconverter/)、[Wise](https://wise.com/currency-converter) 或 [OANDA](https://www.oanda.com/currency-converter/) 查询最新汇率）。当无需换算时使用 `"currency": "USD", "costUnit": "USD"`。
 
 支持的展示币种：`USD`、`CNY`、`EUR`、`GBP`、`JPY`（见 `cache-hit.config.example.json`）。暂未实现类似 visual-cache 的 `/cache-currency` 斜杠命令。
 
diff --git a/cache-hit.config.example.json b/cache-hit.config.example.json
index 01ddc7d..2299fe3 100644
--- a/cache-hit.config.example.json
+++ b/cache-hit.config.example.json
@@ -3,6 +3,7 @@
   "currency": "CNY",
   "costUnit": "USD",
   "rate": 6.77,
+  "$comment-rate": "Manual exchange-rate snapshot USD→currency (6.77 = USD→CNY at the time this was written; does not auto-update). Omit to keep the built-in default 6.77, or set \"currency\": \"USD\" to skip conversion. Current rates: xe.com, wise.com, oanda.com.",
   "display": {
     "lang": "en",
     "panelBorder": true,
diff --git a/package.json b/package.json
index cba7ba7..f2c2351 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "opencode-cache-hit",
-  "version": "0.7.0",
+  "version": "0.7.1",
   "description": "OpenCode TUI sidebar: prompt cache hit rate, tokens & cost with sub-agent rollup. Works with opencode-visual-cache; optional per-call JSONL timeline.",
   "type": "module",
   "license": "MIT",
diff --git a/src/format-cost.ts b/src/format-cost.ts
index 16addb2..41d86f7 100644
--- a/src/format-cost.ts
+++ b/src/format-cost.ts
@@ -26,6 +26,7 @@ export const CURRENCY_PRESETS: Record<CurrencyCode, { symbol: string; decimals:
 export const DEFAULT_COST_DISPLAY: CostDisplayConfig = {
   currency: "CNY",
   costUnit: "USD",
+  // Manual snapshot of USD→CNY at the time this was written; users override via config.
   rate: 6.77,
 }
 
diff --git a/src/load-config.ts b/src/load-config.ts
index fed0569..bddc39b 100644
--- a/src/load-config.ts
+++ b/src/load-config.ts
@@ -7,6 +7,7 @@ import {
   normalizePluginConfig,
   DEFAULT_PLUGIN_CONFIG,
 } from "./plugin-config.ts"
+import { parseJsonc } from "./jsonc.ts"
 
 /** Parent of `src/` (plugin package root). Do not wrap in `dirname` — `..` already resolves there. */
 export const PLUGIN_ROOT = fileURLToPath(new URL("..", import.meta.url))
@@ -21,9 +22,9 @@ export function cloneDefault(): PluginConfig {
   return structuredClone(DEFAULT_PLUGIN_CONFIG)
 }
 
-function tryRead(path: string): PluginConfig | null {
+export function tryRead(path: string): PluginConfig | null {
   try {
-    return normalizePluginConfig(JSON.parse(readFileSync(path, "utf8")))
+    return normalizePluginConfig(parseJsonc(readFileSync(path, "utf8")))
   } catch {
     return null
   }
diff --git a/tests/load-config.test.ts b/tests/load-config.test.ts
index f96dcfb..a29613b 100644
--- a/tests/load-config.test.ts
+++ b/tests/load-config.test.ts
@@ -1,7 +1,8 @@
 import { describe, test, expect } from "bun:test"
-import { existsSync } from "node:fs"
+import { existsSync, mkdtempSync, rmSync, writeFileSync } from "node:fs"
+import { tmpdir } from "node:os"
 import { join } from "node:path"
-import { CONFIG_PATH, PLUGIN_ROOT, XDG_CONFIG_PATH, cloneDefault, loadPluginConfig } from "../src/load-config.ts"
+import { CONFIG_PATH, PLUGIN_ROOT, XDG_CONFIG_PATH, cloneDefault, loadPluginConfig, tryRead } from "../src/load-config.ts"
 import { DEFAULT_PLUGIN_CONFIG } from "../src/plugin-config.ts"
 
 describe("load-config paths", () => {
@@ -44,4 +45,42 @@ describe("load-config paths", () => {
     expect(DEFAULT_PLUGIN_CONFIG.timeline.toolSummary).toEqual({ allTools: true, bash: false })
     expect(DEFAULT_PLUGIN_CONFIG.display.lang).toBe("en")
   })
+
+  test("parses JSONC configs — comments and trailing commas", () => {
+    const dir = mkdtempSync(join(tmpdir(), "cache-hit-"))
+    const path = join(dir, "cache-hit.json")
+    writeFileSync(
+      path,
+      [
+        "{",
+        '  // line comment',
+        '  "currency": "USD",',
+        '  "costUnit": "USD",',
+        '  "display": { "lang": "zh" }, // trailing comma + comment',
+        '  /* block comment */ "timeline": { "enabled": false },',
+        "}",
+      ].join("\n"),
+    )
+    try {
+      const cfg = tryRead(path)
+      expect(cfg).not.toBeNull()
+      expect(cfg?.cost.currency).toBe("USD")
+      expect(cfg?.cost.costUnit).toBe("USD")
+      expect(cfg?.display.lang).toBe("zh")
+      expect(cfg?.timeline.enabled).toBe(false)
+    } finally {
+      rmSync(dir, { recursive: true, force: true })
+    }
+  })
+
+  test("returns null for malformed config content", () => {
+    const dir = mkdtempSync(join(tmpdir(), "cache-hit-"))
+    const path = join(dir, "bad.json")
+    writeFileSync(path, "{ nope")
+    try {
+      expect(tryRead(path)).toBeNull()
+    } finally {
+      rmSync(dir, { recursive: true, force: true })
+    }
+  })
 })