feat(send): --stdin and --body-file so bodies bypass the sender shell and argv (#378)

README.ja.md

@@ -315,7 +315,8 @@ $agmsg
 ### シェル（任意のエージェント）
 
 ```bash
-~/.agents/skills/<cmd>/scripts/send.sh <team> <from> <to> "<message>" [--force]
+~/.agents/skills/<cmd>/scripts/send.sh <team> <from> <to> --stdin [--force]
+~/.agents/skills/<cmd>/scripts/send.sh <team> <from> <to> --body-file <path> [--force]
 ~/.agents/skills/<cmd>/scripts/inbox.sh <team> <agent_id>
 ~/.agents/skills/<cmd>/scripts/history.sh <team> [agent_id] [limit]
 ~/.agents/skills/<cmd>/scripts/team.sh <team>
@@ -325,7 +326,19 @@ $agmsg
 ~/.agents/skills/<cmd>/scripts/reset.sh <project_path> <type> [agent_id]
 ```
 
-`send.sh` は4つの位置引数 `<team> <from> <to> "<message>"` に加えて、末尾に任意で `--force` を取る。シェルが1つの引数として認識するようメッセージはクォートすること — クォートされていないスペース入りメッセージは誤って分割される。`from`・`to` はどちらも `<team>` に事前登録済みである必要があり、未登録の名前は(登録済み一覧を添えて)エラーになる — 意図的な事前登録前送信をしたい場合のみ `--force` でこのチェックを迂回できる。
+`send.sh` は `<team> <from> <to>` に続けてメッセージを取り、末尾に任意で `--force` を取る。`from`・`to` はどちらも `<team>` に事前登録済みである必要があり、未登録の名前は(登録済み一覧を添えて)エラーになる — 意図的な事前登録前送信をしたい場合のみ `--force` でこのチェックを迂回できる。
+
+メッセージは `--stdin` または `--body-file <path>` で渡す。どちらもファイルディスクリプタから本文をそのまま読むため、本文がシェルを通ることも argv に載ることもない。ヒアドキュメントの区切り子は、本文中に単独行として現れ得ないものを選ぶこと — 本文に `AGMSG_BODY` だけの行があるとそこでヒアドキュメントが終わり、残りがシェルコマンドとして実行されてしまう。それを排除できない場合は `--body-file` を使う:
+
+```bash
+~/.agents/skills/<cmd>/scripts/send.sh myteam alice bob --stdin <<'AGMSG_BODY'
+ここに書いた内容はバイト単位でそのまま届く — バッククォートも $(...) もクォートもそのまま
+AGMSG_BODY
+
+~/.agents/skills/<cmd>/scripts/send.sh myteam alice bob --body-file ./message.txt
+```
+
+従来の位置引数形式 — `send.sh <team> <from> <to> "<message>"` — も引き続き動作するが、**非推奨**である(#378)。このメッセージは agmsg が受け取る前にシェルが解釈するため、本文中のバッククォートや `$(...)` がそこで評価されうる。さらに Windows では MSYS の argv 変換によって長い本文が 8186 バイトで無言のうちに切り詰められる。**エージェントが組み立てたメッセージでは使ってはならない**。本文がちょうど `--`・`--stdin`・`--body-file`・`--force` そのものである場合は、直前に `--` を置くこと: `send.sh <team> <from> <to> -- --stdin`（本文が `--` なら `-- --`）
 
 ## FAQ / 設計メモ
 
@@ -406,7 +419,7 @@ DBとチーム設定は保持される。更新されるのはスクリプトと
 
 ```bash
 # 独立したストアに対して実行
-AGMSG_STORAGE_PATH=/tmp/agmsg-sandbox ./scripts/send.sh myteam alice bob "hi"
+printf 'hi' | AGMSG_STORAGE_PATH=/tmp/agmsg-sandbox ./scripts/send.sh myteam alice bob --stdin
 ```
 
 ### サンドボックス互換性（Claude Code）

README.md

@@ -329,7 +329,8 @@ See [docs/opencode.md](docs/opencode.md) for full setup instructions.
 ### Shell (any agent)
 
 ```bash
-~/.agents/skills/<cmd>/scripts/send.sh <team> <from> <to> "<message>" [--force]
+~/.agents/skills/<cmd>/scripts/send.sh <team> <from> <to> --stdin [--force]
+~/.agents/skills/<cmd>/scripts/send.sh <team> <from> <to> --body-file <path> [--force]
 ~/.agents/skills/<cmd>/scripts/inbox.sh <team> <agent_id>
 ~/.agents/skills/<cmd>/scripts/history.sh <team> [agent_id] [limit]
 ~/.agents/skills/<cmd>/scripts/team.sh <team>
@@ -339,7 +340,19 @@ See [docs/opencode.md](docs/opencode.md) for full setup instructions.
 ~/.agents/skills/<cmd>/scripts/reset.sh <project_path> <type> [agent_id]
 ```
 
-`send.sh` takes four positional arguments — `<team> <from> <to> "<message>"` — plus an optional trailing `--force`. Quote the message so the shell sees it as one argument; an unquoted message with spaces will be misparsed. Both `from` and `to` must already be registered in `<team>`; an unregistered name errors out (listing the currently registered names) instead of silently storing an undeliverable message. Pass `--force` to bypass this check for an intentional pre-registration send.
+`send.sh` takes `<team> <from> <to>`, then the message, then an optional trailing `--force`. Both `from` and `to` must already be registered in `<team>`; an unregistered name errors out (listing the currently registered names) instead of silently storing an undeliverable message. Pass `--force` to bypass this check for an intentional pre-registration send.
+
+Give the message via `--stdin` or `--body-file <path>`. Both read the body verbatim from a file descriptor, so it never passes through your shell and never becomes an argv entry. Pick a heredoc delimiter the body cannot contain on a line by itself — a body with a bare `AGMSG_BODY` line would end the heredoc early and the rest would run as shell commands. When you cannot rule that out, use `--body-file`.
+
+```bash
+~/.agents/skills/<cmd>/scripts/send.sh myteam alice bob --stdin <<'AGMSG_BODY'
+whatever you write here arrives byte-for-byte — backticks, $(...), quotes and all
+AGMSG_BODY
+
+~/.agents/skills/<cmd>/scripts/send.sh myteam alice bob --body-file ./message.txt
+```
+
+The older positional form — `send.sh <team> <from> <to> "<message>"` — still works, but it is **deprecated** (#378). Your shell parses that message before agmsg ever sees it, so backticks or `$(...)` in the body can be evaluated there, and on Windows a long body is silently truncated at 8186 bytes by MSYS's argv conversion. A message composed by an agent **must not** use it. If your body happens to be literally `--`, `--stdin`, `--body-file`, or `--force`, put `--` in front of it: `send.sh <team> <from> <to> -- --stdin` — and for a body of `--`, that is `-- --`.
 
 ## FAQ / Design notes
 
@@ -425,7 +438,7 @@ The message store path resolves as **`AGMSG_STORAGE_PATH` (env) > built-in defau
 
 ```bash
 # Run against an isolated store
-AGMSG_STORAGE_PATH=/tmp/agmsg-sandbox ./scripts/send.sh myteam alice bob "hi"
+printf 'hi' | AGMSG_STORAGE_PATH=/tmp/agmsg-sandbox ./scripts/send.sh myteam alice bob --stdin
 ```
 
 ### Sandbox compatibility (Claude Code)

SKILL.md

@@ -7,7 +7,7 @@ description: Cross-agent messaging via SQLite. Send messages between Claude Code
 
 **IMPORTANT: Always use the provided scripts. NEVER directly read or edit config files, DB, or team data. There is NO register.sh — use join.sh to join a team.**
 
-**Shell requirement:** All agmsg scripts are Bash scripts. Always execute them via `bash`, never via PowerShell or cmd directly. If your default shell is not Bash (e.g. PowerShell on Windows), wrap every command with `bash -lc '...'`. Example: `bash -lc '~/.agents/skills/agmsg/scripts/send.sh myteam alice bob "hello"'`. Do NOT construct DB paths manually — the scripts handle path resolution internally. If you need to redirect storage, use `AGMSG_STORAGE_PATH` (the supported override).
+**Shell requirement:** All agmsg scripts are Bash scripts. Always execute them via `bash`, never via PowerShell or cmd directly. If your default shell is not Bash (e.g. PowerShell on Windows), wrap every command with `bash -lc '...'`. Example: `bash -lc '~/.agents/skills/agmsg/scripts/inbox.sh myteam alice'`. Do NOT construct DB paths manually — the scripts handle path resolution internally. If you need to redirect storage, use `AGMSG_STORAGE_PATH` (the supported override).
 
 ## How to use
 
@@ -58,9 +58,28 @@ Do NOT manually edit config files. Always use join.sh. If the name was recently
 # Check inbox (marks messages as read) — DEFAULT action
 ~/.agents/skills/agmsg/scripts/inbox.sh <team> <agent_id>
 
-# Send a message (from/to must already be registered in <team>; add --force to bypass)
+# Send a message (from/to must already be registered in <team>; add --force to bypass).
+# Pass the body via --stdin or --body-file. Both read it verbatim from a file
+# descriptor, so it never goes through a shell and never becomes an argv entry.
+# Pick a delimiter the body cannot contain on a line by itself — a body with a
+# bare AGMSG_BODY line would end the heredoc early and the rest would run as
+# shell commands. When you cannot rule that out, use --body-file.
+~/.agents/skills/agmsg/scripts/send.sh <team> <from_agent> <to_agent> --stdin [--force] <<'AGMSG_BODY'
+message body goes here, verbatim — backticks, $(...), quotes all pass through untouched
+AGMSG_BODY
+~/.agents/skills/agmsg/scripts/send.sh <team> <from_agent> <to_agent> --body-file /path/to/body.txt [--force]
+
+# DEPRECATED — do NOT use for a message you compose yourself (#378). A positional
+# message goes through YOUR shell before agmsg ever sees it, so backticks or
+# $(...) in the body can be evaluated there, and on Windows a long body is
+# silently truncated at 8186 bytes. It still works, for callers that predate the
+# flags above; new sends use --stdin or --body-file.
 ~/.agents/skills/agmsg/scripts/send.sh <team> <from_agent> <to_agent> "<message>" [--force]
 
+# A body that IS `--` or one of the flag names still works — put `--` before it.
+~/.agents/skills/agmsg/scripts/send.sh <team> <from_agent> <to_agent> -- --stdin
+~/.agents/skills/agmsg/scripts/send.sh <team> <from_agent> <to_agent> -- --
+
 # Message history
 ~/.agents/skills/agmsg/scripts/history.sh <team> [agent_id] [limit]
 

docs/building-on-agmsg.md

@@ -58,13 +58,18 @@ flows use:
 
 | Action | Script |
 |---|---|
-| Send a message | `scripts/send.sh <team> <from> <to> <body>` |
+| Send a message | `scripts/send.sh <team> <from> <to> --stdin` (body on stdin) or `--body-file <path>` |
 | Join a team / register an agent | `scripts/join.sh <team> <name> <type> <project>` |
 | Rename an agent | `scripts/rename.sh <team> <old> <new>` |
 | Remove an agent from a team | `scripts/leave.sh <team> <name>` |
 | Check delivery mode | `scripts/delivery.sh status [<type> <project>]` |
 | Set delivery mode | `scripts/delivery.sh set <mode> <type> <project>` |
 
+`send.sh` also still accepts the message as a positional argument, but that
+form is **deprecated** (#378): the caller's shell parses the body before
+agmsg sees it, and on Windows MSYS truncates a long one at 8186 bytes. A body
+your integration composes MUST NOT use it — pass it on stdin or from a file.
+
 These are the same scripts `/agmsg` (or your configured command) itself
 shells out to — there is no more-privileged internal path. Treat them as the
 only sanctioned way to mutate agmsg state; nothing outside `scripts/` should

scripts/drivers/types/antigravity/template.md

@@ -5,7 +5,9 @@ description: Cross-agent messaging via SQLite. Send messages between Claude Code
 
 Agent messaging command. **IMPORTANT: Always use the provided scripts. NEVER directly read or edit config files, DB, or team data. There is NO register.sh — use join.sh to join a team.**
 
-**Shell requirement:** All agmsg scripts are Bash scripts. Always execute them via `bash`, never via PowerShell or cmd directly. If your default shell is not Bash (e.g. PowerShell on Windows), wrap every command with `bash -lc '...'`. Example: `bash -lc '~/.agents/skills/__SKILL_NAME__/scripts/send.sh myteam alice bob "hello"'`. Do NOT construct DB paths manually — the scripts handle path resolution internally. If you need to redirect storage, use `AGMSG_STORAGE_PATH` (the supported override).
+**Shell requirement:** All agmsg scripts are Bash scripts. Always execute them via `bash`, never via PowerShell or cmd directly. If your default shell is not Bash (e.g. PowerShell on Windows), wrap every command with `bash -lc '...'`. Example: `bash -lc '~/.agents/skills/__SKILL_NAME__/scripts/inbox.sh myteam alice'`. Do NOT construct DB paths manually — the scripts handle path resolution internally. If you need to redirect storage, use `AGMSG_STORAGE_PATH` (the supported override).
+
+**Sending a message:** pass the body on stdin with `--stdin`, or from a file with `--body-file <path>`. Both read it verbatim from a file descriptor, so nothing you write is re-parsed by a shell or capped by an argv limit. The older positional form — `send.sh <team> <from> <to> "<message>"` — is **deprecated** (#378): your shell parses that message before agmsg ever sees it, so backticks or `$(...)` in the body can be evaluated there, and on Windows a long body is silently truncated at 8186 bytes. **A message you compose MUST NOT use the positional form.** If the body is literally `--`, `--stdin`, `--body-file`, or `--force`, put `--` in front of it: `send.sh <team> <from> <to> -- --stdin` — and for a body of `--`, that is `-- --`. Pick a heredoc delimiter the body cannot contain on a line by itself — a body with a bare `AGMSG_BODY` line would end the heredoc early and the rest would run as shell commands. When you cannot rule that out, use `--body-file`.
 
 ## Identity
 
@@ -82,7 +84,12 @@ Four possible outputs:
 1. **IMMEDIATELY** run inbox check for each TEAM: `~/.agents/skills/__SKILL_NAME__/scripts/inbox.sh $TEAM $AGENT`
 2. Do NOT ask the user what to do — just run the inbox check.
 3. If there are messages, read and respond appropriately. To reply:
-   `~/.agents/skills/__SKILL_NAME__/scripts/send.sh $TEAM $AGENT <to_agent> "<message>"`
+
+```bash
+~/.agents/skills/__SKILL_NAME__/scripts/send.sh $TEAM $AGENT <to_agent> --stdin <<'AGMSG_BODY'
+<message>
+AGMSG_BODY
+```
 
 If argument is "history":
 1. Run: `~/.agents/skills/__SKILL_NAME__/scripts/history.sh $TEAM $AGENT`
@@ -93,7 +100,12 @@ If argument is "team":
 If argument starts with "send" (e.g. "send misaki check the server"):
 1. Parse target agent and message from the arguments
 2. Determine which team the target agent belongs to, then run:
-   `~/.agents/skills/__SKILL_NAME__/scripts/send.sh $TEAM $AGENT <to_agent> "<message>"`
+
+```bash
+~/.agents/skills/__SKILL_NAME__/scripts/send.sh $TEAM $AGENT <to_agent> --stdin <<'AGMSG_BODY'
+<message>
+AGMSG_BODY
+```
 
 If argument is "config":
 1. Run: `~/.agents/skills/__SKILL_NAME__/scripts/config.sh show`

scripts/drivers/types/claude-code/template.md

@@ -4,7 +4,9 @@ description: Agent messaging — check inbox, send messages, view history
 
 Agent messaging command. **IMPORTANT: Always use the provided scripts. NEVER directly read or edit config files, DB, or team data. There is NO register.sh — use join.sh to join a team.**
 
-**Shell requirement:** All agmsg scripts are Bash scripts. Always execute them via `bash`, never via PowerShell or cmd directly. If your default shell is not Bash (e.g. PowerShell on Windows), wrap every command with `bash -lc '...'`. Example: `bash -lc '~/.agents/skills/__SKILL_NAME__/scripts/send.sh myteam alice bob "hello"'`. Do NOT construct DB paths manually — the scripts handle path resolution internally. If you need to redirect storage, use `AGMSG_STORAGE_PATH` (the supported override).
+**Shell requirement:** All agmsg scripts are Bash scripts. Always execute them via `bash`, never via PowerShell or cmd directly. If your default shell is not Bash (e.g. PowerShell on Windows), wrap every command with `bash -lc '...'`. Example: `bash -lc '~/.agents/skills/__SKILL_NAME__/scripts/inbox.sh myteam alice'`. Do NOT construct DB paths manually — the scripts handle path resolution internally. If you need to redirect storage, use `AGMSG_STORAGE_PATH` (the supported override).
+
+**Sending a message:** pass the body on stdin with `--stdin`, or from a file with `--body-file <path>`. Both read it verbatim from a file descriptor, so nothing you write is re-parsed by a shell or capped by an argv limit. The older positional form — `send.sh <team> <from> <to> "<message>"` — is **deprecated** (#378): your shell parses that message before agmsg ever sees it, so backticks or `$(...)` in the body can be evaluated there, and on Windows a long body is silently truncated at 8186 bytes. **A message you compose MUST NOT use the positional form.** If the body is literally `--`, `--stdin`, `--body-file`, or `--force`, put `--` in front of it: `send.sh <team> <from> <to> -- --stdin` — and for a body of `--`, that is `-- --`. Pick a heredoc delimiter the body cannot contain on a line by itself — a body with a bare `AGMSG_BODY` line would end the heredoc early and the rest would run as shell commands. When you cannot rule that out, use `--body-file`.
 
 ## Identity
 
@@ -119,7 +121,12 @@ The allowlist merges across scopes and takes effect immediately — no restart n
 1. **IMMEDIATELY** run inbox check for each TEAM: `~/.agents/skills/__SKILL_NAME__/scripts/inbox.sh $TEAM $AGENT`
 2. Do NOT ask the user what to do — just run the inbox check.
 3. If there are messages, read and respond appropriately. To reply:
-   `~/.agents/skills/__SKILL_NAME__/scripts/send.sh $TEAM $AGENT <to_agent> "<message>"`
+
+```bash
+~/.agents/skills/__SKILL_NAME__/scripts/send.sh $TEAM $AGENT <to_agent> --stdin <<'AGMSG_BODY'
+<message>
+AGMSG_BODY
+```
 
 If argument is "history":
 1. Run: `~/.agents/skills/__SKILL_NAME__/scripts/history.sh $TEAM $AGENT`
@@ -130,7 +137,12 @@ If argument is "team":
 If argument starts with "send" (e.g. "send misaki check the server"):
 1. Parse target agent and message from the arguments
 2. Determine which team the target agent belongs to, then run:
-   `~/.agents/skills/__SKILL_NAME__/scripts/send.sh $TEAM $AGENT <to_agent> "<message>"`
+
+```bash
+~/.agents/skills/__SKILL_NAME__/scripts/send.sh $TEAM $AGENT <to_agent> --stdin <<'AGMSG_BODY'
+<message>
+AGMSG_BODY
+```
 
 If argument starts with "actas" followed by an agent name (e.g. "actas alice"):
 1. Parse the new role name. If none was given (e.g. bare "actas", or the user asks you to suggest one), run `~/.agents/skills/__SKILL_NAME__/scripts/team.sh <team>` for each TEAM to see the current roster. Look for a naming convention already in play (e.g. a shared base name with role/number suffixes like `aggie-cc1`/`aggie-cc2`, or names derived from the team name) and, when one exists, propose 2-3 unused names that extend it; otherwise propose 2-3 short, distinctive identity names (not a bare tool-type label). Either way, names must not collide with the roster. Ask the user to pick one or type their own before continuing.