Merge pull request #1017 from typefield/feat/flag-input-file-stdin

feat(corecmd): support @file / stdin input sources on string flags

docs/flag-help-schema-homology.md

@@ -92,6 +92,7 @@ command/Leaf 不再写 `dws.schema.risk`；SafetySpec 走类型化 Final 载荷
 | `Required` / `MarkRequired` | 非空校验 / cobra 硬必填 | 是（`required`） |
 | `RequiredHint`, `Aliases`, `EnvVar` | 校验提示、隐藏别名、环境回退 | 否（执行细节；别名不上主 parameter 表） |
 | `ArgDefault`, `Bind`, `OmitEmpty`, `Trim`, `Transform` | toolArgs 装配语义 | 否（载荷细节；`Bind` 可进 property 映射，但不另造 flag） |
+| `Input` | 额外取值来源：`@path` 读文件 / `-` 读 stdin，在 required/enum/约束/`Validate` 之前原地解析 | 否（今日：能力由作者写进 `Usage` / `SchemaDescription` 文案，是已声明事实而非推断；不另造 flag。目标形态收敛为类型化投影字段，见 RFC §5.3） |
 
 #### 1.2.2 编排 / 执行字段（不算声明）
 

docs/rfc-command-framework-convergence.md

@@ -292,7 +292,7 @@ Definition（仅声明；不可编译）
 
 下列字段**是**框架声明面（经 `corecmd.New` 生效并嵌入 `dws.schema.*`）：
 
-- `Flags`（含 Name/Kind/Default/Required/MarkRequired/Usage 等注册面）
+- `Flags`（含 Name/Kind/Default/Required/MarkRequired/Usage 等注册面；`Input` 是取值来源声明，经 `corecmd.New` 生效但**不**嵌入 `dws.schema.*`，能力靠 `Usage` 文案声明，见 §5.3）
 - `Constraints`
 - **非空** `Risk`（空值 = 运行时当只读确认，且**不**嵌入 `dws.schema.risk`）
 - `ConstParams`（载荷声明；不上用户 flag 表）
@@ -673,6 +673,52 @@ func (k Key[T]) Declare(opts ...FlagOption[T]) FlagSpec
 - 构造时拒绝 `InputSourceInvalid`。
 - 当前没有任何 Shortcut 或 Leaf 声明 `Input`，因此 M1 增加能力且零上线表面变化。让现有命令采用它属于 §9 下的用户可见变更。
 
+`Input` 的框架能力今日已在 `corecmd` 落地（声明即执行的过渡形态，语义与上文目标一致），使用指南：
+
+**今日声明形态**：`FlagSpec.Input []string`，源常量 `corecmd.InputFile`（`"file"`）/ `corecmd.InputStdin`（`"stdin"`）。`helpers.LeafFlag` 是 `corecmd.FlagSpec` 别名，直接可用；`shortcut.Flag.Input` 同形声明，经 `FromShortcut` 映射到 `FlagSpec`。
+
+```go
+// LeafSpec / helpers
+Flags: []helpers.LeafFlag{
+    {
+        Name:  "content",
+        Usage: "文档内容（支持 @文件路径 或 - 读 stdin）",
+        Bind:  "content",
+        Input: []string{corecmd.InputFile, corecmd.InputStdin},
+    },
+}
+
+// shortcut
+Flags: []shortcut.Flag{
+    {Name: "markdown", Desc: "Markdown 内容（支持 @文件路径 或 -）",
+     Input: []string{"file", "stdin"}},
+}
+```
+
+**运行时语义**（`resolveInputFlags`，在 `runDeclaredPreflight` 内、required/enum/约束/Validate 之前执行，原地改写 cobra flag 值）：
+
+- `--flag @path`：文件内容替换取值；`--flag -`：stdin 内容替换取值。
+- `--flag @@value`：转义为字面 `@value`，不做来源解析。
+- 只解析显式 CLI token（主名或别名）；EnvVar 回落与注册默认值透传不解析。
+- 内容前置剥离 UTF-8 BOM；`Trim` 等既有语义照常作用于解析后的值。
+- 读取失败、源不支持、`@` 后空路径都是类型化校验错误（退出码 3）；同时声明两种源而文件读取失败时附 stdin 引导 hint。
+
+**作者守则**：
+
+- 声明即全部能力：required/enum/约束/Validate 校验的已是解析后的真实内容，`Execute`/`Invoke` 无需任何额外代码。
+- `Usage`/`Desc` 必须写明支持 `@路径`/`-`；框架不自动改写 help 文案，今日也不向 Schema 投影（新增投影字段须先过 homology 评审，避免 catalog drift）。
+- `user_required` 确认的写命令若声明 `InputStdin`：stdin 在校验阶段被消费，交互确认将 fail-closed 为 `confirmation_required`，此类调用必须显式 `--yes`（或 `--dry-run`）。
+- **声明前先确认取值空间不会被前缀吃掉**：声明 `InputFile` 后，任何以 `@` 开头的合法值都会被当成文件路径（本产品尤其常见的是 at 提及类取值，如 `--at-user @zhangsan` 会报读取文件失败），用户只能改用 `@@` 转义；声明 `InputStdin` 后字面值 `-` 不可达（与 curl 等约定一致）。若该 flag 的正常取值可能命中这两种形态，就不要声明对应来源。
+- 声明在构造期校验（fail-closed panic）：仅限 `KindString`；源值必须是 `file`/`stdin` 且不重复。
+
+**今日实现与目标形态的差异**（迁移到本节目标 `FlagSpec` 时收敛）：
+
+| 维度 | 今日 | 目标 |
+|---|---|---|
+| 源类型 | `[]string` 常量 | 类型化 `InputSource` |
+| 路径边界 | 直接本地文件 IO | 复用 §5.5.2 本地文件 effect 边界 |
+| Schema 投影 | 无（靠作者在 Usage 声明） | 声明即最终源，随 Catalog 透传 |
+
 核心 FlagSpec 故意没有：
 
 - `Bind`；

internal/corecmd/corecmd.go

@@ -145,6 +145,15 @@ type FlagSpec struct {
 	// alike) and makes a whitespace-only value count as empty in required checks.
 	Trim bool
 
+	// Input declares extra input sources for a KindString flag beyond the
+	// literal command-line value: InputFile enables @path (value replaced by
+	// the file content), InputStdin enables - (value replaced by stdin).
+	// "@@value" always escapes to the literal "@value". Only explicit CLI
+	// tokens are resolved; EnvVar fallback and registration defaults pass
+	// through unchanged. Resolution runs before required/enum/constraint/
+	// Validate checks, so they see the payload content. Empty = flag value only.
+	Input []string
+
 	// Schema parameter final facts (embedded to dws.schema.*; assembly pass-through).
 	Enum              []string // accepted values
 	Format            string   // machine-readable format (e.g. uri)
@@ -365,6 +374,7 @@ func New(spec Spec) *cobra.Command {
 	validateDispatchDecl(spec)
 	validateSafetySpec(spec)
 	validateContractDecl(spec)
+	validateInputSpecs(spec.Use, spec.Flags)
 	// Help prose inherits the declaration when not authored separately:
 	// Selection.Examples (already contract-validated against the real flags)
 	// double as the --help Example block, keeping one authored source.
@@ -476,6 +486,11 @@ func runDeclaredPreflight(cmd *cobra.Command, args []string, spec Spec) error {
 			return err
 		}
 	}
+	// Input resolution rewrites explicit @file / stdin values in place so the
+	// required/enum/constraint/Validate stages below check the payload content.
+	if err := resolveInputFlags(cmd, spec.Flags); err != nil {
+		return err
+	}
 	if err := ValidateRequired(cmd, spec.Flags); err != nil {
 		return err
 	}

internal/corecmd/input.go

@@ -0,0 +1,191 @@
+// Copyright 2026 Alibaba Group
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package corecmd
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"strings"
+
+	"github.com/spf13/cobra"
+
+	apperrors "github.com/DingTalk-Real-AI/dingtalk-workspace-cli/internal/errors"
+	"github.com/DingTalk-Real-AI/dingtalk-workspace-cli/pkg/cmdutil"
+)
+
+// FlagSpec.Input source constants. They declare extra input sources for a
+// KindString flag beyond the literal command-line value, mirroring the
+// lark-cli Flag.Input capability so large payloads (markdown, JSON, CSV)
+// never need shell quoting.
+const (
+	// InputFile allows the flag value @path to be replaced by the file content.
+	InputFile = "file"
+	// InputStdin allows the flag value - to be replaced by the stdin content.
+	InputStdin = "stdin"
+)
+
+// utf8BOM is stripped from file/stdin content so a Windows-edited payload
+// cannot corrupt the first CSV cell or break JSON parsing downstream.
+const utf8BOM = "\ufeff"
+
+// validateInputSpecs rejects malformed Input declarations at build time. Like
+// the other declaration checks this panics: a bad Input spec is a programming
+// error every test and startup path should trip immediately.
+func validateInputSpecs(use string, flags []FlagSpec) {
+	for _, flag := range flags {
+		if len(flag.Input) == 0 {
+			continue
+		}
+		if flag.Kind != KindString {
+			panic(fmt.Sprintf(
+				"command %q flag %q: Input is only supported on KindString flags",
+				use, flag.Name))
+		}
+		seen := map[string]bool{}
+		for _, source := range flag.Input {
+			if source != InputFile && source != InputStdin {
+				panic(fmt.Sprintf(
+					"command %q flag %q: unknown Input source %q (allowed: %s, %s)",
+					use, flag.Name, source, InputFile, InputStdin))
+			}
+			if seen[source] {
+				panic(fmt.Sprintf(
+					"command %q flag %q: duplicate Input source %q",
+					use, flag.Name, source))
+			}
+			seen[source] = true
+		}
+	}
+}
+
+// inputSupports reports whether the flag declared the given input source.
+func inputSupports(flag FlagSpec, source string) bool {
+	for _, s := range flag.Input {
+		if s == source {
+			return true
+		}
+	}
+	return false
+}
+
+// explicitInputFlagName picks the declared name that carries the user's
+// explicit token, mirroring rawValue's order and usability judgement exactly:
+// the main flag wins only when changed and usable (trim-judged only when
+// Trim is set), then declared aliases in order. Diverging here could rewrite
+// an alias that rawValue would shadow (or vice versa). EnvVar fallback and
+// registration defaults are never input-resolved — @file only applies to what
+// the user literally typed.
+func explicitInputFlagName(cmd *cobra.Command, flag FlagSpec) string {
+	usable := func(v string) bool {
+		if flag.Trim {
+			v = strings.TrimSpace(v)
+		}
+		return v != ""
+	}
+	for _, name := range append([]string{flag.Name}, flag.Aliases...) {
+		if cmd.Flags().Changed(name) && usable(cmdutil.MustGetFlag(cmd, name)) {
+			return name
+		}
+	}
+	return ""
+}
+
+// resolveInputFlags rewrites the explicit values of Input-declaring flags
+// before required/enum/constraint/Validate checks, so every downstream stage
+// sees the real payload content. Semantics:
+//
+//   - "-" reads stdin; a process has a single stdin, so a second Input flag
+//     using "-" in the same invocation is rejected.
+//   - "@path" reads the named file (leading/trailing whitespace trimmed).
+//   - "@@value" escapes to the literal "@value" and is not source-resolved.
+//
+// Resolution runs once per invocation inside runDeclaredPreflight. It
+// rewrites the cobra flag value in place (Set keeps Changed=true), so
+// fallback-chain readers (EffectiveValue/BuildArgs) observe the content.
+//
+// Interaction with confirmation: stdin is consumed here, before the Safety
+// prompt of a user_required write would read it; such an interactive prompt
+// then sees EOF and fails closed with confirmation_required. Write commands
+// declaring InputStdin must be invoked with --yes (or --dry-run).
+func resolveInputFlags(cmd *cobra.Command, flags []FlagSpec) error {
+	stdinConsumed := false
+	for _, flag := range flags {
+		if len(flag.Input) == 0 {
+			continue
+		}
+		name := explicitInputFlagName(cmd, flag)
+		if name == "" {
+			continue
+		}
+		raw := cmdutil.MustGetFlag(cmd, name)
+		// Trim flags judge usability on the trimmed value (rawValue), so the
+		// prefix check must agree or " @path" would slip through unresolved.
+		if flag.Trim {
+			raw = strings.TrimSpace(raw)
+		}
+
+		switch {
+		case raw == "-":
+			if !inputSupports(flag, InputStdin) {
+				return apperrors.NewValidation(
+					fmt.Sprintf("参数 --%s 不支持 stdin 输入（-）", flag.Name))
+			}
+			if stdinConsumed {
+				return apperrors.NewValidation(
+					fmt.Sprintf("参数 --%s：stdin（-）只能被一个参数使用", flag.Name),
+					apperrors.WithHint(fmt.Sprintf(
+						"一个进程只有一份 stdin，其余参数请内联传值或用 @文件路径（如 --%s @./payload.json）",
+						flag.Name)))
+			}
+			stdinConsumed = true
+			data, err := io.ReadAll(cmd.InOrStdin())
+			if err != nil {
+				return apperrors.NewValidation(
+					fmt.Sprintf("参数 --%s 读取 stdin 失败：%v", flag.Name, err))
+			}
+			// Setting a registered string flag cannot fail.
+			_ = cmd.Flags().Set(name, strings.TrimPrefix(string(data), utf8BOM))
+
+		case strings.HasPrefix(raw, "@@"):
+			// Escape: strip the first @, keep the rest as a literal inline value.
+			_ = cmd.Flags().Set(name, raw[1:])
+
+		case strings.HasPrefix(raw, "@"):
+			if !inputSupports(flag, InputFile) {
+				return apperrors.NewValidation(
+					fmt.Sprintf("参数 --%s 不支持文件输入（@路径）", flag.Name))
+			}
+			path := strings.TrimSpace(raw[1:])
+			if path == "" {
+				return apperrors.NewValidation(
+					fmt.Sprintf("参数 --%s：@ 后的文件路径不能为空", flag.Name))
+			}
+			data, err := os.ReadFile(path)
+			if err != nil {
+				var opts []apperrors.Option
+				if inputSupports(flag, InputStdin) {
+					// Rejected @file paths are usually absolute (temp files).
+					// Steer toward stdin rather than copying the file around.
+					opts = append(opts, apperrors.WithHint(fmt.Sprintf(
+						"该参数也支持 stdin：把文件内容管道进命令并传 --%s -", flag.Name)))
+				}
+				return apperrors.NewValidation(
+					fmt.Sprintf("参数 --%s 读取文件 %q 失败：%v", flag.Name, path, err), opts...)
+			}
+			_ = cmd.Flags().Set(name, strings.TrimPrefix(string(data), utf8BOM))
+		}
+	}
+	return nil
+}

internal/corecmd/input_test.go

@@ -0,0 +1,334 @@
+// Copyright 2026 Alibaba Group
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package corecmd
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/spf13/cobra"
+)
+
+// newInputCommand builds a Spec whose Invoke captures toolArgs, so tests can
+// assert what the full pipeline (resolution → validation → BuildArgs) ships.
+func newInputCommand(flags []FlagSpec, captured *map[string]any) *cobra.Command {
+	return New(Spec{
+		Use:   "t",
+		Short: "t",
+		Flags: flags,
+		Invoke: func(c *Ctx, toolArgs map[string]any) error {
+			*captured = toolArgs
+			return nil
+		},
+	})
+}
+
+func runInputCommand(t *testing.T, cmd *cobra.Command, args ...string) error {
+	t.Helper()
+	cmd.SetArgs(args)
+	return cmd.Execute()
+}
+
+func writeInputFile(t *testing.T, content string) string {
+	t.Helper()
+	path := filepath.Join(t.TempDir(), "payload.txt")
+	if err := os.WriteFile(path, []byte(content), 0o600); err != nil {
+		t.Fatalf("write fixture: %v", err)
+	}
+	return path
+}
+
+func TestCrossPlatformCoverageResolveInputFlagsFile(t *testing.T) {
+	var got map[string]any
+	cmd := newInputCommand([]FlagSpec{
+		{Name: "content", Usage: "C", Bind: "content", Input: []string{InputFile, InputStdin}},
+	}, &got)
+	path := writeInputFile(t, "# hello\nworld")
+
+	if err := runInputCommand(t, cmd, "--content", "@"+path); err != nil {
+		t.Fatalf("execute: %v", err)
+	}
+	if got["content"] != "# hello\nworld" {
+		t.Fatalf("toolArgs[content] = %q", got["content"])
+	}
+}
+
+func TestCrossPlatformCoverageResolveInputFlagsStdin(t *testing.T) {
+	var got map[string]any
+	cmd := newInputCommand([]FlagSpec{
+		{Name: "content", Usage: "C", Bind: "content", Input: []string{InputStdin}},
+	}, &got)
+	cmd.SetIn(strings.NewReader("piped payload"))
+
+	if err := runInputCommand(t, cmd, "--content", "-"); err != nil {
+		t.Fatalf("execute: %v", err)
+	}
+	if got["content"] != "piped payload" {
+		t.Fatalf("toolArgs[content] = %q", got["content"])
+	}
+}
+
+// The @@ escape keeps a literal leading @ inline and must not be treated as a
+// source reference even when Input is declared.
+func TestCrossPlatformCoverageResolveInputFlagsEscapedAtStaysInline(t *testing.T) {
+	var got map[string]any
+	cmd := newInputCommand([]FlagSpec{
+		{Name: "content", Usage: "C", Bind: "content", Input: []string{InputFile, InputStdin}},
+	}, &got)
+
+	if err := runInputCommand(t, cmd, "--content", "@@literal@x"); err != nil {
+		t.Fatalf("execute: %v", err)
+	}
+	if got["content"] != "@literal@x" {
+		t.Fatalf("toolArgs[content] = %q", got["content"])
+	}
+}
+
+func TestCrossPlatformCoverageResolveInputFlagsBOMStripped(t *testing.T) {
+	var got map[string]any
+	cmd := newInputCommand([]FlagSpec{
+		{Name: "content", Usage: "C", Bind: "content", Input: []string{InputFile}},
+	}, &got)
+	path := writeInputFile(t, "\ufeff{\"a\":1}")
+
+	if err := runInputCommand(t, cmd, "--content", "@"+path); err != nil {
+		t.Fatalf("execute: %v", err)
+	}
+	if got["content"] != "{\"a\":1}" {
+		t.Fatalf("toolArgs[content] = %q", got["content"])
+	}
+}
+
+// Required must be satisfied by the resolved payload, proving resolution runs
+// before the required stage.
+func TestCrossPlatformCoverageResolveInputFlagsSatisfiesRequired(t *testing.T) {
+	var got map[string]any
+	cmd := newInputCommand([]FlagSpec{
+		{Name: "content", Usage: "C", Bind: "content", Required: true, Input: []string{InputFile}},
+	}, &got)
+	path := writeInputFile(t, "payload")
+
+	if err := runInputCommand(t, cmd, "--content", "@"+path); err != nil {
+		t.Fatalf("execute: %v", err)
+	}
+	if got["content"] != "payload" {
+		t.Fatalf("toolArgs[content] = %q", got["content"])
+	}
+}
+
+// Enum validation sees the resolved content, not the "@path" token.
+func TestCrossPlatformCoverageResolveInputFlagsEnumValidatesResolvedContent(t *testing.T) {
+	var got map[string]any
+	cmd := newInputCommand([]FlagSpec{
+		{Name: "mode", Usage: "M", Bind: "mode", Enum: []string{"asc", "desc"}, Input: []string{InputFile}},
+	}, &got)
+	path := writeInputFile(t, "sideways")
+
+	err := runInputCommand(t, cmd, "--mode", "@"+path)
+	if err == nil || !strings.Contains(err.Error(), "不合法") {
+		t.Fatalf("expected enum rejection on resolved content, got %v", err)
+	}
+}
+
+// A value passed through a declared alias is resolved exactly like the main
+// name (fallback-chain parity).
+func TestCrossPlatformCoverageResolveInputFlagsAliasResolved(t *testing.T) {
+	var got map[string]any
+	cmd := newInputCommand([]FlagSpec{
+		{Name: "content", Usage: "C", Bind: "content", Aliases: []string{"body"}, Input: []string{InputFile}},
+	}, &got)
+	path := writeInputFile(t, "via alias")
+
+	if err := runInputCommand(t, cmd, "--body", "@"+path); err != nil {
+		t.Fatalf("execute: %v", err)
+	}
+	if got["content"] != "via alias" {
+		t.Fatalf("toolArgs[content] = %q", got["content"])
+	}
+}
+
+// When the main flag shadows a changed alias (rawValue usability order), the
+// shadowed alias must not be input-resolved: resolution targets exactly the
+// name the fallback chain will read. The whitespace main value is usable for
+// a non-Trim flag, and the alias path does not exist on purpose — a resolver
+// that wrongly picked the alias would fail the read instead of shipping "   ".
+func TestCrossPlatformCoverageResolveInputFlagsShadowedAliasNotResolved(t *testing.T) {
+	var got map[string]any
+	cmd := newInputCommand([]FlagSpec{
+		{Name: "content", Usage: "C", Bind: "content", Aliases: []string{"body"}, Input: []string{InputFile}},
+	}, &got)
+	missing := filepath.Join(t.TempDir(), "missing.txt")
+
+	if err := runInputCommand(t, cmd, "--content", "   ", "--body", "@"+missing); err != nil {
+		t.Fatalf("execute: %v", err)
+	}
+	if got["content"] != "   " {
+		t.Fatalf("toolArgs[content] = %q", got["content"])
+	}
+}
+
+func TestCrossPlatformCoverageResolveInputFlagsFileNotSupported(t *testing.T) {
+	var got map[string]any
+	cmd := newInputCommand([]FlagSpec{
+		{Name: "content", Usage: "C", Bind: "content", Input: []string{InputStdin}},
+	}, &got)
+
+	err := runInputCommand(t, cmd, "--content", "@/tmp/whatever.txt")
+	if err == nil || !strings.Contains(err.Error(), "不支持文件输入") {
+		t.Fatalf("expected file-input rejection, got %v", err)
+	}
+}
+
+func TestCrossPlatformCoverageResolveInputFlagsStdinNotSupported(t *testing.T) {
+	var got map[string]any
+	cmd := newInputCommand([]FlagSpec{
+		{Name: "content", Usage: "C", Bind: "content", Input: []string{InputFile}},
+	}, &got)
+	cmd.SetIn(strings.NewReader("x"))
+
+	err := runInputCommand(t, cmd, "--content", "-")
+	if err == nil || !strings.Contains(err.Error(), "不支持 stdin") {
+		t.Fatalf("expected stdin rejection, got %v", err)
+	}
+}
+
+func TestCrossPlatformCoverageResolveInputFlagsSingleStdinConsumer(t *testing.T) {
+	var got map[string]any
+	cmd := newInputCommand([]FlagSpec{
+		{Name: "first", Usage: "F", Bind: "first", Input: []string{InputStdin}},
+		{Name: "second", Usage: "S", Bind: "second", Input: []string{InputStdin}},
+	}, &got)
+	cmd.SetIn(strings.NewReader("x"))
+
+	err := runInputCommand(t, cmd, "--first", "-", "--second", "-")
+	if err == nil || !strings.Contains(err.Error(), "只能被一个参数使用") {
+		t.Fatalf("expected single-stdin rejection, got %v", err)
+	}
+}
+
+// failingReader (corecmd_test.go) fails every read, making the stdin error
+// branch reachable.
+func TestCrossPlatformCoverageResolveInputFlagsStdinReadFailure(t *testing.T) {
+	var got map[string]any
+	cmd := newInputCommand([]FlagSpec{
+		{Name: "content", Usage: "C", Bind: "content", Input: []string{InputStdin}},
+	}, &got)
+	cmd.SetIn(failingReader{})
+
+	err := runInputCommand(t, cmd, "--content", "-")
+	if err == nil || !strings.Contains(err.Error(), "读取 stdin 失败") {
+		t.Fatalf("expected stdin read failure, got %v", err)
+	}
+}
+
+func TestCrossPlatformCoverageResolveInputFlagsFileNotFound(t *testing.T) {
+	var got map[string]any
+	cmd := newInputCommand([]FlagSpec{
+		{Name: "content", Usage: "C", Bind: "content", Input: []string{InputFile, InputStdin}},
+	}, &got)
+
+	err := runInputCommand(t, cmd, "--content", "@"+filepath.Join(t.TempDir(), "missing.txt"))
+	if err == nil || !strings.Contains(err.Error(), "读取文件") {
+		t.Fatalf("expected read failure, got %v", err)
+	}
+}
+
+func TestCrossPlatformCoverageResolveInputFlagsEmptyPathAfterAt(t *testing.T) {
+	var got map[string]any
+	cmd := newInputCommand([]FlagSpec{
+		{Name: "content", Usage: "C", Bind: "content", Input: []string{InputFile}},
+	}, &got)
+
+	err := runInputCommand(t, cmd, "--content", "@   ")
+	if err == nil || !strings.Contains(err.Error(), "文件路径不能为空") {
+		t.Fatalf("expected empty-path rejection, got %v", err)
+	}
+}
+
+// A flag without Input keeps its literal value even when it looks like a
+// source reference — resolution is strictly opt-in per declaration.
+func TestCrossPlatformCoverageResolveInputFlagsNoInputSpecPassthrough(t *testing.T) {
+	var got map[string]any
+	cmd := newInputCommand([]FlagSpec{
+		{Name: "token", Usage: "T", Bind: "token"},
+	}, &got)
+
+	if err := runInputCommand(t, cmd, "--token", "@not-a-file"); err != nil {
+		t.Fatalf("execute: %v", err)
+	}
+	if got["token"] != "@not-a-file" {
+		t.Fatalf("toolArgs[token] = %q", got["token"])
+	}
+}
+
+// Registration defaults and env fallback are never input-resolved: @file only
+// applies to what the user literally typed on the command line.
+func TestCrossPlatformCoverageResolveInputFlagsDefaultNotResolved(t *testing.T) {
+	var got map[string]any
+	cmd := newInputCommand([]FlagSpec{
+		{Name: "content", Usage: "C", Bind: "content", Default: "@not-a-file", Input: []string{InputFile}},
+	}, &got)
+
+	if err := runInputCommand(t, cmd); err != nil {
+		t.Fatalf("execute: %v", err)
+	}
+	if got["content"] != "@not-a-file" {
+		t.Fatalf("toolArgs[content] = %q", got["content"])
+	}
+}
+
+// Trim flags judge usability on the trimmed value (rawValue), so a leading
+// whitespace before @ must still resolve instead of shipping as a literal.
+func TestCrossPlatformCoverageResolveInputFlagsTrimmedLeadingSpace(t *testing.T) {
+	var got map[string]any
+	cmd := newInputCommand([]FlagSpec{
+		{Name: "content", Usage: "C", Bind: "content", Trim: true, Input: []string{InputFile}},
+	}, &got)
+	path := writeInputFile(t, "trimmed payload")
+
+	if err := runInputCommand(t, cmd, "--content", " @"+path); err != nil {
+		t.Fatalf("execute: %v", err)
+	}
+	if got["content"] != "trimmed payload" {
+		t.Fatalf("toolArgs[content] = %q", got["content"])
+	}
+}
+
+func TestCrossPlatformCoverageValidateInputSpecsPanics(t *testing.T) {
+	cases := []struct {
+		name string
+		flag FlagSpec
+	}{
+		{"non-string kind", FlagSpec{Name: "n", Kind: KindInt, Input: []string{InputFile}}},
+		{"unknown source", FlagSpec{Name: "s", Input: []string{"url"}}},
+		{"duplicate source", FlagSpec{Name: "s", Input: []string{InputFile, InputFile}}},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			defer func() {
+				if recover() == nil {
+					t.Fatal("expected panic")
+				}
+			}()
+			New(Spec{
+				Use:    "t",
+				Short:  "t",
+				Flags:  []FlagSpec{tc.flag},
+				Invoke: func(c *Ctx, toolArgs map[string]any) error { return nil },
+			})
+		})
+	}
+}

internal/shortcut/adapter.go

@@ -217,6 +217,7 @@ func fromShortcutFlags(flags []Flag) []corecmd.FlagSpec {
 			RequiredError:  fmt.Sprintf("缺少必填参数 --%s：%s", f.Name, f.Desc),
 			Enum:           append([]string(nil), f.Enum...),
 			Aliases:        append([]string(nil), f.Aliases...),
+			Input:          append([]string(nil), f.Input...),
 		})
 	}
 	return out

internal/shortcut/types.go

@@ -107,6 +107,12 @@ type Flag struct {
 	// compatibility escape hatch for aliases that were historically public.
 	Aliases        []string `json:"-"`
 	AliasesVisible bool     `json:"-"`
+	// Input declares extra input sources for a string flag beyond the literal
+	// command-line value: "file" enables @path (value replaced by the file
+	// content), "stdin" enables - (value replaced by stdin). "@@value" escapes
+	// to the literal "@value". Resolution happens before Required/Enum/Validate
+	// checks. Empty = flag value only.
+	Input []string `json:"input,omitempty"`
 }
 
 // ConstraintKind is a machine-readable cross-parameter or custom validation