WIP: Initial support for deltachat gateway

Features:
- Support voice messages
- Optional crossposting
- Automatic account creation
- Custom avatar image

README.md

@@ -494,6 +494,7 @@ Talk to your PicoClaw through 19+ messaging platforms:
 | **QQ** | Easy (AppID + AppSecret) | WebSocket | [Guide](docs/channels/qq/README.md) |
 | **Slack** | Easy (bot + app token) | Socket Mode | [Guide](docs/channels/slack/README.md) |
 | **Matrix** | Medium (homeserver + token) | Sync API | [Guide](docs/channels/matrix/README.md) |
+| **Delta Chat** | Easy (account script or email/password) | JSON-RPC (email/E2EE) | [Guide](docs/channels/deltachat/README.md) |
 | **DingTalk** | Medium (client credentials) | Stream | [Guide](docs/channels/dingtalk/README.md) |
 | **Feishu / Lark** | Medium (App ID + Secret) | WebSocket/SDK | [Guide](docs/channels/feishu/README.md) |
 | **LINE** | Medium (credentials + webhook) | Webhook | [Guide](docs/channels/line/README.md) |

docs/channels/deltachat/README.md

@@ -0,0 +1,148 @@
+> Back to [README](../../../README.md)
+
+# Delta Chat Channel
+
+PicoClaw can run as a Delta Chat bot by launching a local
+`deltachat-rpc-server` process and talking to it over JSON-RPC. The RPC server
+handles the email account, IMAP/SMTP connection, message store, and encryption
+keys.
+
+## Install
+
+Install the Delta Chat RPC server. If `deltachat-rpc-server` is on `PATH`,
+PicoClaw can find it automatically; otherwise set `rpc_server_path` to the
+exact binary path.
+
+```bash
+pip install deltachat-rpc-server
+which deltachat-rpc-server
+```
+
+Prebuilt binaries are also available from the
+[Delta Chat core releases](https://github.com/deltachat/deltachat-core-rust/releases).
+
+## Configure
+
+The easiest setup is to let PicoClaw create a chatmail account in Delta
+Chat's local account store. Put a relay marker in `email` using an empty local
+part, for example `@nine.testrun.org`:
+
+```json
+{
+  "channel_list": {
+    "deltachat": {
+      "enabled": true,
+      "type": "deltachat",
+      "allow_from": ["friend@example.org"],
+      "group_trigger": {
+        "mention_only": true
+      },
+      "settings": {
+        "email": "@nine.testrun.org",
+        "display_name": "PicoClaw Bot",
+        "avatar_image": "/home/me/bot-avatar.png"
+      }
+    }
+  }
+}
+```
+
+On startup, PicoClaw creates the account through `deltachat-rpc-server`, then
+stops with an error that contains the generated address. Replace the relay
+marker with that full email address and run PicoClaw again:
+
+```json
+{
+  "email": "bot123@nine.testrun.org",
+  "display_name": "PicoClaw Bot",
+  "avatar_image": "/home/me/bot-avatar.png"
+}
+```
+
+If `email` is missing, the startup error lists the built-in relay choices copied
+from Parla. You can use one of those relay markers, or a custom chatmail relay
+with the same `@server.name` form.
+
+`password` is not needed for PicoClaw-created chatmail accounts. Omit it when
+`email` points to an already configured account in `data_dir`; the JSON-RPC
+server owns the mailbox password. The legacy password-based path remains only
+for classic email accounts that PicoClaw must configure itself. In that mode,
+`password` is a secure field; on first config load it is moved to
+`~/.picoclaw/.security.yml`, and it can also be set with
+`PICOCLAW_CHANNELS_DELTACHAT_PASSWORD`.
+
+`display_name` and `avatar_image` are optional profile settings. When present,
+PicoClaw applies them on every startup, so changing the avatar path in config is
+enough to update the bot profile.
+
+| Field | Required | Description |
+|-------|----------|-------------|
+| `email` | Yes | Full bot mailbox address, or first-run relay marker such as `@nine.testrun.org` |
+| `rpc_server_path` | No | Path to `deltachat-rpc-server`; only needed when it is not on `PATH` |
+| `password` | No | Legacy only; required when PicoClaw must configure/reconfigure a classic mailbox itself |
+| `display_name` | No | Startup-applied profile name shown to contacts and used for group mention detection |
+| `avatar_image` | No | Startup-applied profile avatar image path; `~` is expanded. Missing files are warned and ignored |
+| `data_dir` | No | Account database directory. Default: `~/.picoclaw/deltachat/<channel-name>` |
+| `invite_link` | No | Delta Chat invite link to join on startup |
+| `allow_crosspost` | No | Default `false`. When `true`, senders allowed by `allow_from` may use `message` tool targets outside the current chat, or resolve recipients by email/contact/chat name |
+| `imap_server`, `imap_port` | No | Manual IMAP override for password-based configuration |
+| `smtp_server`, `smtp_port` | No | Manual SMTP override for password-based configuration |
+
+Standard channel fields such as `allow_from`, `group_trigger`, and
+`reasoning_channel_id` also apply.
+
+## First Run
+
+With `email` set to `@server`, PicoClaw creates the chatmail account, prints
+the generated full email in the startup error, and exits. Update `email` to that
+full address and run PicoClaw again. On later runs, PicoClaw selects the
+configured account by `email`, applies optional profile settings, marks it as a
+bot, and starts IO.
+
+With a new `data_dir` plus legacy `password`, PicoClaw can still configure a
+classic email account and validate the mailbox credentials; after that, the
+account is reused from the local data directory.
+
+Delta Chat requires peers to learn the bot's encryption key before messaging
+it. On startup PicoClaw prints the bot invite link and QR code. Add the bot from
+Delta Chat with that invite, not by typing the bare email address.
+
+## Behavior
+
+- Direct chats always respond after `allow_from` passes.
+- Group chats follow `group_trigger`; without one, every group message is
+  handled.
+- Messages from the bot itself, device chats, and info/system messages are
+  ignored.
+- Accepted inbound messages are marked seen after the allow-list check.
+- Incoming attachments (images, audio, video, documents) are registered with
+  the media store and handed to the agent, so it can view images or operate on
+  the files directly. If no media store is available, the path is appended
+  inline as `[attachment: /path]` instead.
+- Outbound attachments are supported: when the agent emits media, each file is
+  sent as a Delta Chat message (with the caption as text). Delta Chat infers the
+  view type from the file, so images, GIFs, and videos render natively.
+- Crosspost recipient lookup is disabled by default. The agent can always reply
+  to the current numeric chat ID, but sending to another numeric chat ID or
+  resolving an email/contact/chat name requires `allow_crosspost: true`
+  and the current sender must pass `allow_from`; `allow_from: ["*"]` allows this
+  for any sender.
+- Voice is supported in both directions when voice providers are configured:
+  incoming voice notes are transcribed by the agent's ASR and the transcript is
+  passed to the model; the agent can reply with synthesized speech, which is
+  delivered as a native Delta Chat voice message (`send_tts`). This requires an
+  ASR and/or TTS provider under `voice` — it is not Delta Chat-specific config.
+
+## Troubleshooting
+
+| Symptom | Fix |
+|---------|-----|
+| `deltachat-rpc-server not found on PATH` or `rpc_server_path ... not found` | Install the RPC server on PATH, or set `rpc_server_path` to an absolute path |
+| `email is required` | Choose one listed chatmail server, set `email` to a first-run marker such as `@nine.testrun.org`, run `picoclaw g`, then replace it with the generated full email |
+| `created chatmail account ...` | Replace the `@server` marker in `email` with the generated full email and run PicoClaw again |
+| `account ... is not configured in data_dir` | Point `data_dir` at the existing JSON-RPC account store, or use `email="@server"` to create one |
+| `configure (check email/password/server)` | Check credentials, app password requirements, or IMAP/SMTP overrides |
+| Bot does not answer in a group | Check `group_trigger`; mention `display_name` or use a configured prefix |
+| Bot ignores a sender | Add the sender email to `allow_from`, or use `["*"]` for open access |
+| Sender cannot message the bot | Re-add the bot with the startup QR/invite so Delta Chat can establish encryption |
+| Agent cannot send to an email/name/other chat ID | Enable `settings.allow_crosspost` and allow the controlling sender in `allow_from`; this capability is disabled by default for privacy |

pkg/agent/agent_media.go

@@ -100,10 +100,15 @@ func resolveMediaRefs(
 
 			localPath, meta, err := store.ResolveWithMeta(ref)
 			if err != nil {
-				logger.WarnCF("agent", "Failed to resolve media ref", map[string]any{
+				fields := map[string]any{
 					"ref":   ref,
 					"error": err.Error(),
-				})
+				}
+				if idx < currentTurnStart {
+					logger.DebugCF("agent", "Skipped stale historical media ref", fields)
+				} else {
+					logger.WarnCF("agent", "Failed to resolve media ref", fields)
+				}
 				continue
 			}
 

pkg/channels/base.go

@@ -266,7 +266,7 @@ func (c *BaseChannel) HandleMessageWithContext(
 	media []string,
 	inboundCtx bus.InboundContext,
 	senderOpts ...bus.SenderInfo,
-) {
+) error {
 	// Use SenderInfo-based allow check when available, else fall back to string
 	var sender bus.SenderInfo
 	if len(senderOpts) > 0 {
@@ -275,11 +275,11 @@ func (c *BaseChannel) HandleMessageWithContext(
 	senderID := strings.TrimSpace(inboundCtx.SenderID)
 	if sender.CanonicalID != "" || sender.PlatformID != "" {
 		if !c.IsAllowedSender(sender) {
-			return
+			return nil
 		}
 	} else {
 		if !c.IsAllowed(senderID) {
-			return
+			return nil
 		}
 	}
 
@@ -350,7 +350,9 @@ func (c *BaseChannel) HandleMessageWithContext(
 			"chat_id": deliveryChatID,
 			"error":   err.Error(),
 		})
+		return err
 	}
+	return nil
 }
 
 // HandleInboundContext publishes a normalized inbound message using only the
@@ -361,8 +363,8 @@ func (c *BaseChannel) HandleInboundContext(
 	media []string,
 	inboundCtx bus.InboundContext,
 	senderOpts ...bus.SenderInfo,
-) {
+) error {
-	c.HandleMessageWithContext(ctx, deliveryChatID, content, media, inboundCtx, senderOpts...)
+	return c.HandleMessageWithContext(ctx, deliveryChatID, content, media, inboundCtx, senderOpts...)
 }
 
 func (c *BaseChannel) SetRunning(running bool) {

pkg/channels/deltachat/handler.go

@@ -0,0 +1,398 @@
+package deltachat
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
+	"unicode"
+
+	"github.com/google/uuid"
+
+	"github.com/sipeed/picoclaw/pkg/bus"
+	"github.com/sipeed/picoclaw/pkg/channels"
+	"github.com/sipeed/picoclaw/pkg/config"
+	"github.com/sipeed/picoclaw/pkg/identity"
+	"github.com/sipeed/picoclaw/pkg/logger"
+	"github.com/sipeed/picoclaw/pkg/media"
+	"github.com/sipeed/picoclaw/pkg/utils"
+)
+
+// listen is the inbound message loop. It blocks on wait_next_msgs and feeds
+// each new message into the PicoClaw inbound pipeline.
+func (c *DeltaChatChannel) listen() {
+	logger.InfoCF("deltachat", "Listening for messages", map[string]any{
+		"account_id": c.accountID,
+		"email":      c.selfAddr,
+	})
+	for c.IsRunning() && c.ctx.Err() == nil {
+		raw, err := c.rpc.call(c.ctx, "wait_next_msgs", c.accountID)
+		if err != nil {
+			if c.ctx.Err() != nil || !c.IsRunning() {
+				return
+			}
+			logger.ErrorCF("deltachat", "wait_next_msgs failed", map[string]any{"error": err.Error()})
+			time.Sleep(time.Second)
+			continue
+		}
+
+		var messageIDs []int64
+		if err := json.Unmarshal(raw, &messageIDs); err != nil {
+			continue
+		}
+
+		if len(messageIDs) > 0 {
+			logger.DebugCF("deltachat", "Received message batch", map[string]any{
+				"count": len(messageIDs),
+			})
+		}
+		for _, messageID := range messageIDs {
+			c.handleMessage(messageID)
+		}
+	}
+}
+
+// handleMessage fetches one message, applies inbound filtering, and publishes it.
+func (c *DeltaChatChannel) handleMessage(messageID int64) {
+	msg, err := c.getMessage(messageID)
+	if err != nil {
+		logger.DebugCF("deltachat", "get_message failed", map[string]any{
+			"message_id": messageID,
+			"error":      err.Error(),
+		})
+		return
+	}
+
+	if msg.IsInfo || (strings.TrimSpace(msg.Text) == "" && msg.File == "") {
+		return
+	}
+
+	senderAddr := ""
+	if msg.Sender != nil {
+		senderAddr = msg.Sender.Address
+	}
+	if senderAddr != "" && strings.EqualFold(senderAddr, c.selfAddr) {
+		logger.DebugCF("deltachat", "Drop: own message", map[string]any{"message_id": messageID})
+		return
+	}
+
+	chat, err := c.getFullChat(msg.ChatID)
+	if err != nil {
+		logger.DebugCF("deltachat", "get_full_chat_by_id failed", map[string]any{
+			"chat_id": msg.ChatID,
+			"error":   err.Error(),
+		})
+		return
+	}
+	// Device messages are core-generated notices, not real conversations.
+	if chat.IsDeviceChat {
+		logger.DebugCF("deltachat", "Drop: device message", map[string]any{"chat_id": msg.ChatID})
+		return
+	}
+	isGroup := chat.ChatType != chatTypeSingle
+
+	logger.DebugCF("deltachat", "Inbound message", map[string]any{
+		"message_id": messageID,
+		"chat_id":    msg.ChatID,
+		"from":       senderAddr,
+		"is_group":   isGroup,
+		"has_file":   msg.File != "",
+		"text_len":   len(strings.TrimSpace(msg.Text)),
+	})
+
+	senderName := senderAddr
+	if msg.Sender != nil {
+		if msg.Sender.DisplayName != "" {
+			senderName = msg.Sender.DisplayName
+		} else if msg.Sender.Name != "" {
+			senderName = msg.Sender.Name
+		}
+	}
+	if senderName == "" {
+		senderName = "unknown"
+	}
+
+	chatID := strconv.FormatInt(msg.ChatID, 10)
+	messageIDStr := strconv.FormatInt(msg.ID, 10)
+
+	content := strings.TrimSpace(msg.Text)
+
+	// Register any attachment with the media store so the agent pipeline can
+	// view images and operate on files. The ref is scoped to the same key the
+	// BaseChannel derives for this message, so it is released with the turn.
+	var mediaRefs []string
+	if msg.File != "" {
+		scope := channels.BuildMediaScope(c.Name(), chatID, messageIDStr)
+		if ref := c.registerInboundFile(scope, msg); ref != "" {
+			mediaRefs = append(mediaRefs, ref)
+		} else {
+			// Fallback when no media store is available: surface the path inline
+			// so the attachment is not silently lost.
+			annotation := fmt.Sprintf("[attachment: %s]", msg.File)
+			if content == "" {
+				content = annotation
+			} else {
+				content = content + "\n" + annotation
+			}
+		}
+	}
+
+	// A file with no caption still warrants a turn; give the agent a minimal
+	// placeholder so the message survives the empty-content guard below. Audio
+	// gets a "[voice]" tag specifically, so the agent's transcription step can
+	// substitute the transcript in place rather than appending it.
+	if content == "" && len(mediaRefs) > 0 {
+		if utils.IsAudioFile(msg.FileName, msg.FileMime) {
+			content = "[voice]"
+		} else {
+			content = "[media]"
+		}
+	}
+
+	sender := bus.SenderInfo{
+		Platform:    config.ChannelDeltaChat,
+		PlatformID:  senderAddr,
+		CanonicalID: identity.BuildCanonicalID(config.ChannelDeltaChat, senderAddr),
+		Username:    senderAddr,
+		DisplayName: senderName,
+	}
+
+	if !c.IsAllowedSender(sender) {
+		logger.DebugCF("deltachat", "Drop: sender not in allow_from", map[string]any{
+			"from": senderAddr,
+		})
+		return
+	}
+
+	isMentioned := false
+	if isGroup {
+		botName := c.config.DisplayName
+		if botName == "" {
+			botName = c.selfAddr
+		}
+		isMentioned = mentionsBot(content, botName, c.selfAddr)
+		respond, cleaned := c.ShouldRespondInGroup(isMentioned, content)
+		if !respond {
+			logger.DebugCF("deltachat", "Drop: group trigger not satisfied", map[string]any{
+				"chat_id":   msg.ChatID,
+				"mentioned": isMentioned,
+			})
+			return
+		}
+		content = cleaned
+	}
+
+	if strings.TrimSpace(content) == "" {
+		return
+	}
+
+	metadata := map[string]string{
+		"platform":  config.ChannelDeltaChat,
+		"chat_name": chat.Name,
+	}
+	if msg.File != "" {
+		metadata["file"] = msg.File
+		metadata["file_name"] = msg.FileName
+		metadata["file_mime"] = msg.FileMime
+	}
+
+	inboundCtx := bus.InboundContext{
+		Channel:   config.ChannelDeltaChat,
+		ChatID:    chatID,
+		SenderID:  senderAddr,
+		MessageID: messageIDStr,
+		Mentioned: isMentioned,
+		Raw:       metadata,
+	}
+	if isGroup {
+		inboundCtx.ChatType = "group"
+	} else {
+		inboundCtx.ChatType = "direct"
+	}
+
+	logger.DebugCF("deltachat", "Dispatching to agent", map[string]any{
+		"chat_id":   chatID,
+		"chat_type": inboundCtx.ChatType,
+		"from":      senderAddr,
+	})
+	if err := c.HandleInboundContext(c.ctx, chatID, content, mediaRefs, inboundCtx, sender); err != nil {
+		logger.ErrorCF("deltachat", "Dispatch failed; leaving message unseen", map[string]any{
+			"message_id": messageID,
+			"chat_id":    chatID,
+			"error":      err.Error(),
+		})
+		return
+	}
+	if _, err := c.rpc.call(c.ctx, "markseen_msgs", c.accountID, []int64{messageID}); err != nil {
+		logger.WarnCF("deltachat", "Failed to mark message seen", map[string]any{
+			"message_id": messageID,
+			"chat_id":    chatID,
+			"error":      err.Error(),
+		})
+	}
+}
+
+// registerInboundFile records an inbound attachment with the media store under
+// the given scope and returns its media:// ref. Returns "" when there is no
+// media store or registration fails, letting the caller fall back to an inline
+// path annotation.
+//
+// Delta Chat stores attachments inside the account directory, next to the
+// credential database — a location tools are intentionally NOT allowed to read.
+// We therefore copy the single attachment out into the shared media temp dir
+// (which read_file/load_image are permitted to access) and register that copy,
+// so the agent can actually open the file. The copy is store-managed and deleted
+// when the turn's scope is released.
+func (c *DeltaChatChannel) registerInboundFile(scope string, msg *dcMessage) string {
+	store := c.GetMediaStore()
+	if store == nil {
+		return ""
+	}
+	filename := msg.FileName
+	if filename == "" {
+		filename = filepath.Base(msg.File)
+	}
+
+	localPath, err := copyToMediaTemp(msg.File, filename)
+	if err != nil {
+		logger.WarnCF("deltachat", "Failed to copy attachment into media dir", map[string]any{
+			"file":  msg.File,
+			"error": err.Error(),
+		})
+		return ""
+	}
+
+	ref, err := store.Store(localPath, media.MediaMeta{
+		Filename:      filename,
+		ContentType:   msg.FileMime,
+		Source:        config.ChannelDeltaChat,
+		CleanupPolicy: media.CleanupPolicyDeleteOnCleanup,
+	}, scope)
+	if err != nil {
+		logger.WarnCF("deltachat", "Failed to register attachment with media store", map[string]any{
+			"file":  localPath,
+			"error": err.Error(),
+		})
+		_ = os.Remove(localPath)
+		return ""
+	}
+	return ref
+}
+
+// copyToMediaTemp copies srcPath into the shared media temp directory under a
+// unique name and returns the destination path. The media temp dir is the
+// location the read_file/load_image tools are permitted to read, so copying here
+// makes the attachment readable without exposing Delta Chat's account directory.
+func copyToMediaTemp(srcPath, filename string) (string, error) {
+	if err := os.MkdirAll(media.TempDir(), 0o700); err != nil {
+		return "", err
+	}
+	safe := utils.SanitizeFilename(filename)
+	if safe == "" {
+		safe = filepath.Base(srcPath)
+	}
+	dstPath := filepath.Join(media.TempDir(), uuid.NewString()[:8]+"_"+safe)
+
+	src, err := os.Open(srcPath)
+	if err != nil {
+		return "", err
+	}
+	defer src.Close()
+
+	dst, err := os.Create(dstPath)
+	if err != nil {
+		return "", err
+	}
+	if _, err := io.Copy(dst, src); err != nil {
+		dst.Close()
+		_ = os.Remove(dstPath)
+		return "", err
+	}
+	if err := dst.Close(); err != nil {
+		_ = os.Remove(dstPath)
+		return "", err
+	}
+	return dstPath, nil
+}
+
+func (c *DeltaChatChannel) getMessage(messageID int64) (*dcMessage, error) {
+	raw, err := c.rpc.call(c.ctx, "get_message", c.accountID, messageID)
+	if err != nil {
+		return nil, err
+	}
+	var msg dcMessage
+	if err := json.Unmarshal(raw, &msg); err != nil {
+		return nil, err
+	}
+	return &msg, nil
+}
+
+func (c *DeltaChatChannel) getFullChat(chatID int64) (*dcChat, error) {
+	raw, err := c.rpc.call(c.ctx, "get_full_chat_by_id", c.accountID, chatID)
+	if err != nil {
+		return nil, err
+	}
+	var chat dcChat
+	if err := json.Unmarshal(raw, &chat); err != nil {
+		return nil, err
+	}
+	return &chat, nil
+}
+
+// mentionsBot reports whether the message references the bot by display name or
+// the local-part of its email address (a common addressing convention).
+func mentionsBot(content, displayName, email string) bool {
+	if containsMentionToken(content, displayName) {
+		return true
+	}
+	if local, _, ok := strings.Cut(email, "@"); ok && local != "" {
+		if containsMentionToken(content, "@"+local) {
+			return true
+		}
+	}
+	return false
+}
+
+func containsMentionToken(content, token string) bool {
+	token = strings.TrimSpace(token)
+	if token == "" {
+		return false
+	}
+	contentRunes := []rune(strings.ToLower(content))
+	tokenRunes := []rune(strings.ToLower(token))
+	if len(tokenRunes) == 0 || len(tokenRunes) > len(contentRunes) {
+		return false
+	}
+	for i := 0; i <= len(contentRunes)-len(tokenRunes); i++ {
+		if !sameRunes(contentRunes[i:i+len(tokenRunes)], tokenRunes) {
+			continue
+		}
+		before := i == 0 || !isMentionWordRune(contentRunes[i-1])
+		afterIdx := i + len(tokenRunes)
+		after := afterIdx >= len(contentRunes) || !isMentionWordRune(contentRunes[afterIdx])
+		if before && after {
+			return true
+		}
+	}
+	return false
+}
+
+func sameRunes(a, b []rune) bool {
+	if len(a) != len(b) {
+		return false
+	}
+	for i := range a {
+		if a[i] != b[i] {
+			return false
+		}
+	}
+	return true
+}
+
+func isMentionWordRune(r rune) bool {
+	return unicode.IsLetter(r) || unicode.IsDigit(r) || r == '_'
+}

pkg/channels/deltachat/init.go

@@ -0,0 +1,35 @@
+package deltachat
+
+import (
+	"github.com/sipeed/picoclaw/pkg/bus"
+	"github.com/sipeed/picoclaw/pkg/channels"
+	"github.com/sipeed/picoclaw/pkg/config"
+)
+
+func init() {
+	channels.RegisterFactory(
+		config.ChannelDeltaChat,
+		func(channelName, channelType string, cfg *config.Config, b *bus.MessageBus) (channels.Channel, error) {
+			bc := cfg.Channels[channelName]
+			if bc == nil || !bc.Enabled {
+				return nil, nil
+			}
+			decoded, err := bc.GetDecoded()
+			if err != nil {
+				return nil, err
+			}
+			c, ok := decoded.(*config.DeltaChatSettings)
+			if !ok {
+				return nil, channels.ErrSendFailed
+			}
+			ch, err := NewDeltaChatChannel(bc, c, b)
+			if err != nil {
+				return nil, err
+			}
+			if channelName != config.ChannelDeltaChat {
+				ch.SetName(channelName)
+			}
+			return ch, nil
+		},
+	)
+}

pkg/channels/deltachat/rpc.go

@@ -0,0 +1,188 @@
+package deltachat
+
+import (
+	"bufio"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"os/exec"
+	"sync"
+
+	"github.com/sipeed/picoclaw/pkg/logger"
+)
+
+// rpcRequest is a single JSON-RPC 2.0 request. Delta Chat uses positional
+// (array) parameters.
+type rpcRequest struct {
+	JSONRPC string `json:"jsonrpc"`
+	ID      uint64 `json:"id"`
+	Method  string `json:"method"`
+	Params  []any  `json:"params,omitempty"`
+}
+
+// rpcResponse is a single JSON-RPC 2.0 response.
+type rpcResponse struct {
+	ID     uint64          `json:"id"`
+	Result json.RawMessage `json:"result"`
+	Error  *rpcError       `json:"error"`
+}
+
+type rpcError struct {
+	Code    int    `json:"code"`
+	Message string `json:"message"`
+}
+
+func (e *rpcError) Error() string {
+	return fmt.Sprintf("deltachat rpc error %d: %s", e.Code, e.Message)
+}
+
+// rpcClient drives a `deltachat-rpc-server` child process over stdio using
+// newline-delimited JSON-RPC 2.0. The server answers requests asynchronously
+// and out of order, so every call is correlated back to its caller by id.
+type rpcClient struct {
+	cmd    *exec.Cmd
+	stdin  io.WriteCloser
+	stdout io.ReadCloser
+
+	mu      sync.Mutex
+	nextID  uint64
+	pending map[uint64]chan rpcResponse
+	closed  bool
+}
+
+// startRPC spawns the RPC server with DC_ACCOUNTS_PATH pointing at dataDir and
+// begins the background read loop.
+func startRPC(serverPath, dataDir string) (*rpcClient, error) {
+	cmd := exec.Command(serverPath)
+	cmd.Env = append(cmd.Environ(), "DC_ACCOUNTS_PATH="+dataDir)
+
+	stdin, err := cmd.StdinPipe()
+	if err != nil {
+		return nil, fmt.Errorf("deltachat rpc stdin: %w", err)
+	}
+	stdout, err := cmd.StdoutPipe()
+	if err != nil {
+		return nil, fmt.Errorf("deltachat rpc stdout: %w", err)
+	}
+	// Let the server's logs flow to our stderr for easy diagnostics.
+	cmd.Stderr = logWriter{}
+
+	if err := cmd.Start(); err != nil {
+		return nil, fmt.Errorf("start deltachat-rpc-server (%s): %w", serverPath, err)
+	}
+
+	c := &rpcClient{
+		cmd:     cmd,
+		stdin:   stdin,
+		stdout:  stdout,
+		pending: make(map[uint64]chan rpcResponse),
+	}
+	go c.readLoop()
+	return c, nil
+}
+
+// readLoop reads newline-delimited responses and dispatches them to waiters.
+func (c *rpcClient) readLoop() {
+	reader := bufio.NewReader(c.stdout)
+	for {
+		line, err := reader.ReadBytes('\n')
+		if len(line) > 0 {
+			var resp rpcResponse
+			if jsonErr := json.Unmarshal(line, &resp); jsonErr == nil && resp.ID != 0 {
+				c.mu.Lock()
+				ch := c.pending[resp.ID]
+				delete(c.pending, resp.ID)
+				c.mu.Unlock()
+				if ch != nil {
+					ch <- resp
+				}
+			}
+		}
+		if err != nil {
+			c.failAll(err)
+			return
+		}
+	}
+}
+
+// failAll wakes every pending caller with an error (used on EOF / shutdown).
+func (c *rpcClient) failAll(err error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.closed = true
+	for id, ch := range c.pending {
+		ch <- rpcResponse{Error: &rpcError{Code: -1, Message: "rpc closed: " + err.Error()}}
+		delete(c.pending, id)
+	}
+}
+
+// call issues one request and blocks until the matching response arrives, the
+// context is canceled, or the server goes away.
+func (c *rpcClient) call(ctx context.Context, method string, params ...any) (json.RawMessage, error) {
+	c.mu.Lock()
+	if c.closed {
+		c.mu.Unlock()
+		return nil, fmt.Errorf("deltachat rpc: connection closed")
+	}
+	c.nextID++
+	id := c.nextID
+	ch := make(chan rpcResponse, 1)
+	c.pending[id] = ch
+	c.mu.Unlock()
+
+	req := rpcRequest{JSONRPC: "2.0", ID: id, Method: method, Params: params}
+	data, err := json.Marshal(req)
+	if err != nil {
+		c.clearPending(id)
+		return nil, err
+	}
+	data = append(data, '\n')
+
+	c.mu.Lock()
+	_, err = c.stdin.Write(data)
+	c.mu.Unlock()
+	if err != nil {
+		c.clearPending(id)
+		return nil, fmt.Errorf("deltachat rpc write %s: %w", method, err)
+	}
+
+	select {
+	case <-ctx.Done():
+		c.clearPending(id)
+		return nil, ctx.Err()
+	case resp := <-ch:
+		if resp.Error != nil {
+			return nil, resp.Error
+		}
+		return resp.Result, nil
+	}
+}
+
+func (c *rpcClient) clearPending(id uint64) {
+	c.mu.Lock()
+	delete(c.pending, id)
+	c.mu.Unlock()
+}
+
+// close terminates the RPC server process.
+func (c *rpcClient) close() {
+	c.mu.Lock()
+	c.closed = true
+	c.mu.Unlock()
+	if c.stdin != nil {
+		_ = c.stdin.Close()
+	}
+	if c.cmd != nil && c.cmd.Process != nil {
+		_ = c.cmd.Process.Kill()
+		_ = c.cmd.Wait()
+	}
+}
+
+// logWriter forwards deltachat-rpc-server stderr lines into the logger.
+type logWriter struct{}
+
+func (logWriter) Write(p []byte) (int, error) {
+	logger.DebugC("deltachat", string(p))
+	return len(p), nil
+}

pkg/config/config.go

@@ -599,6 +599,31 @@ type MatrixSettings struct {
 	CryptoPassphrase   string       `json:"crypto_passphrase,omitempty"    yaml:"-"`
 }
 
+// DeltaChatSettings configures the Delta Chat channel. Delta Chat is an
+// email-based, end-to-end encrypted messenger; PicoClaw talks to a local
+// `deltachat-rpc-server` process over JSON-RPC (stdio).
+//
+// Email is the only required setting. A full address selects an already
+// configured account in DataDir; a first-run marker such as "@nine.testrun.org"
+// creates a chatmail account and tells the user which full email to save.
+// Mailbox credentials stay in the Delta Chat account store. DisplayName and
+// AvatarImage are optional profile settings applied on startup. Password remains
+// only for legacy PicoClaw-managed email configuration.
+type DeltaChatSettings struct {
+	Email          string       `json:"email"                     yaml:"-"                  env:"PICOCLAW_CHANNELS_DELTACHAT_EMAIL"`
+	Password       SecureString `json:"password,omitzero"         yaml:"password,omitempty" env:"PICOCLAW_CHANNELS_DELTACHAT_PASSWORD"`
+	DisplayName    string       `json:"display_name,omitempty"    yaml:"-"                  env:"PICOCLAW_CHANNELS_DELTACHAT_DISPLAY_NAME"`
+	AvatarImage    string       `json:"avatar_image,omitempty"    yaml:"-"                  env:"PICOCLAW_CHANNELS_DELTACHAT_AVATAR_IMAGE"`
+	DataDir        string       `json:"data_dir,omitempty"        yaml:"-"                  env:"PICOCLAW_CHANNELS_DELTACHAT_DATA_DIR"`
+	RPCServerPath  string       `json:"rpc_server_path,omitempty" yaml:"-"                  env:"PICOCLAW_CHANNELS_DELTACHAT_RPC_SERVER_PATH"`
+	InviteLink     string       `json:"invite_link,omitempty"     yaml:"-"                  env:"PICOCLAW_CHANNELS_DELTACHAT_INVITE_LINK"`
+	AllowCrosspost bool         `json:"allow_crosspost,omitempty" yaml:"-"                  env:"PICOCLAW_CHANNELS_DELTACHAT_ALLOW_CROSSPOST"`
+	IMAPServer     string       `json:"imap_server,omitempty"     yaml:"-"`
+	IMAPPort       int          `json:"imap_port,omitempty"       yaml:"-"`
+	SMTPServer     string       `json:"smtp_server,omitempty"     yaml:"-"`
+	SMTPPort       int          `json:"smtp_port,omitempty"       yaml:"-"`
+}
+
 type LINESettings struct {
 	ChannelSecret      SecureString `json:"channel_secret,omitzero"       yaml:"channel_secret,omitempty"       env:"PICOCLAW_CHANNELS_LINE_CHANNEL_SECRET"`
 	ChannelAccessToken SecureString `json:"channel_access_token,omitzero" yaml:"channel_access_token,omitempty" env:"PICOCLAW_CHANNELS_LINE_CHANNEL_ACCESS_TOKEN"`

pkg/config/config_channel.go

@@ -27,6 +27,7 @@ const (
 	ChannelDingTalk       = "dingtalk"
 	ChannelSlack          = "slack"
 	ChannelMatrix         = "matrix"
+	ChannelDeltaChat      = "deltachat"
 	ChannelLINE           = "line"
 	ChannelOneBot         = "onebot"
 	ChannelQQ             = "qq"
@@ -669,6 +670,7 @@ var channelSettingsFactory = map[string]any{
 	ChannelDingTalk:       (DingTalkSettings{}),
 	ChannelSlack:          (SlackSettings{}),
 	ChannelMatrix:         (MatrixSettings{}),
+	ChannelDeltaChat:      (DeltaChatSettings{}),
 	ChannelLINE:           (LINESettings{}),
 	ChannelOneBot:         (OneBotSettings{}),
 	ChannelQQ:             (QQSettings{}),

pkg/config/config_test.go

@@ -1019,6 +1019,38 @@ func TestDefaultConfig_ChannelStreamingDisabled(t *testing.T) {
 	}
 }
 
+func TestDefaultConfig_DeltaChatExample(t *testing.T) {
+	cfg := DefaultConfig()
+
+	deltachat := cfg.Channels.Get(ChannelDeltaChat)
+	if deltachat == nil {
+		t.Fatal("DefaultConfig() missing deltachat channel")
+	}
+	if deltachat.Enabled {
+		t.Fatal("DefaultConfig().deltachat should be disabled")
+	}
+	if !deltachat.GroupTrigger.MentionOnly {
+		t.Fatal("DefaultConfig().deltachat should use mention-only group trigger")
+	}
+	decoded, err := deltachat.GetDecoded()
+	if err != nil {
+		t.Fatalf("deltachat GetDecoded() error = %v", err)
+	}
+	settings, ok := decoded.(*DeltaChatSettings)
+	if !ok {
+		t.Fatalf("deltachat settings type = %T, want *DeltaChatSettings", decoded)
+	}
+	if settings.Email != "@nine.testrun.org" {
+		t.Fatalf("DefaultConfig().deltachat.settings.email = %q, want @nine.testrun.org", settings.Email)
+	}
+	if settings.Password.String() != "" {
+		t.Fatal("DefaultConfig().deltachat.settings.password should be empty")
+	}
+	if settings.DisplayName == "" {
+		t.Fatal("DefaultConfig().deltachat.settings.display_name should be populated")
+	}
+}
+
 func TestValidateSingletonChannels_RejectsMultipleInstances(t *testing.T) {
 	channels := ChannelsConfig{
 		"pico1": &Channel{Enabled: true, Type: ChannelPico},

pkg/config/defaults.go

@@ -549,6 +549,13 @@ func defaultChannels() ChannelsConfig {
 				"join_on_invite": true,
 			},
 		},
+		"deltachat": map[string]any{
+			"group_trigger": map[string]any{"mention_only": true},
+			"settings": map[string]any{
+				"email":        "@nine.testrun.org",
+				"display_name": "PicoClaw Bot",
+			},
+		},
 		"line": map[string]any{
 			"group_trigger": map[string]any{"mention_only": true},
 			"settings": map[string]any{

pkg/gateway/gateway.go

@@ -19,6 +19,7 @@ import (
 	"github.com/sipeed/picoclaw/pkg/audio/tts"
 	"github.com/sipeed/picoclaw/pkg/bus"
 	"github.com/sipeed/picoclaw/pkg/channels"
+	_ "github.com/sipeed/picoclaw/pkg/channels/deltachat"
 	_ "github.com/sipeed/picoclaw/pkg/channels/dingtalk"
 	_ "github.com/sipeed/picoclaw/pkg/channels/discord"
 	_ "github.com/sipeed/picoclaw/pkg/channels/feishu"