feat(googlechat): Google Chat channel integration

cmd/gateway.go

@@ -18,6 +18,7 @@ import (
 	"github.com/nextlevelbuilder/goclaw/internal/channels"
 	"github.com/nextlevelbuilder/goclaw/internal/channels/discord"
 	"github.com/nextlevelbuilder/goclaw/internal/channels/feishu"
+	googlechatchannel "github.com/nextlevelbuilder/goclaw/internal/channels/googlechat"
 	slackchannel "github.com/nextlevelbuilder/goclaw/internal/channels/slack"
 	"github.com/nextlevelbuilder/goclaw/internal/channels/telegram"
 	"github.com/nextlevelbuilder/goclaw/internal/channels/whatsapp"
@@ -807,6 +808,7 @@ func runGateway() {
 		instanceLoader.RegisterFactory(channels.TypeZaloPersonal, zalopersonal.FactoryWithPendingStore(pgStores.PendingMessages))
 		instanceLoader.RegisterFactory(channels.TypeWhatsApp, whatsapp.Factory)
 		instanceLoader.RegisterFactory(channels.TypeSlack, slackchannel.FactoryWithPendingStore(pgStores.PendingMessages))
+		instanceLoader.RegisterFactory(channels.TypeGoogleChat, googlechatchannel.Factory)
 		if err := instanceLoader.LoadAll(context.Background()); err != nil {
 			slog.Error("failed to load channel instances from DB", "error", err)
 		}
@@ -1069,11 +1071,13 @@ func runGateway() {
 	// Compiled via build tags: `go build -tags tsnet` to enable.
 	mux := server.BuildMux()
 
-	// Mount channel webhook handlers on the main mux (e.g. Feishu /feishu/events).
-	// This allows webhook-based channels to share the main server port.
-	for _, route := range channelMgr.WebhookHandlers() {
-		mux.Handle(route.Path, route.Handler)
-		slog.Info("webhook route mounted on gateway", "path", route.Path)
+	// Mount channel webhook handlers dynamically (e.g. Feishu /feishu/events, Google Chat).
+	// Uses wrapper handlers so channels added later via Reload() are served without re-mounting.
+	channelMgr.MountNewWebhookRoutes(mux)
+
+	// Pass mux to instanceLoader so Reload() can mount webhook routes for new channels.
+	if instanceLoader != nil {
+		instanceLoader.SetMux(mux)
 	}
 
 	tsCleanup := initTailscale(ctx, cfg, mux)

cmd/gateway_channels_setup.go

@@ -13,6 +13,7 @@ import (
 	"github.com/nextlevelbuilder/goclaw/internal/channels"
 	"github.com/nextlevelbuilder/goclaw/internal/channels/discord"
 	"github.com/nextlevelbuilder/goclaw/internal/channels/feishu"
+	googlechatchannel "github.com/nextlevelbuilder/goclaw/internal/channels/googlechat"
 	slackchannel "github.com/nextlevelbuilder/goclaw/internal/channels/slack"
 	"github.com/nextlevelbuilder/goclaw/internal/channels/telegram"
 	"github.com/nextlevelbuilder/goclaw/internal/channels/whatsapp"
@@ -97,6 +98,17 @@ func registerConfigChannels(cfg *config.Config, channelMgr *channels.Manager, ms
 			slog.Info("feishu/lark channel enabled (config)")
 		}
 	}
+
+	gcCfg := cfg.Channels.GoogleChat
+	if gcCfg.Enabled && gcCfg.ServiceAccountJSON != "" && instanceLoader == nil {
+		gc, err := googlechatchannel.New(gcCfg, msgBus, pgStores.Pairing)
+		if err != nil {
+			slog.Error("failed to initialize googlechat channel", "error", err)
+		} else {
+			channelMgr.RegisterChannel(channels.TypeGoogleChat, gc)
+			slog.Info("google chat channel enabled (config)")
+		}
+	}
 }
 
 // wireChannelRPCMethods registers WS RPC methods for channels, instances, agent links, and teams.

go.mod

@@ -24,11 +24,13 @@ require (
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.40.0
 	go.opentelemetry.io/otel/sdk v1.40.0
 	go.opentelemetry.io/otel/trace v1.40.0
+	golang.org/x/oauth2 v0.35.0
 	golang.org/x/time v0.14.0
 	tailscale.com v1.94.2
 )
 
 require (
+	cloud.google.com/go/compute/metadata v0.9.0 // indirect
 	filippo.io/edwards25519 v1.1.0 // indirect
 	github.com/akutz/memconn v0.1.0 // indirect
 	github.com/alexbrainman/sspi v0.0.0-20231016080023-1a75b4708caa // indirect
@@ -102,8 +104,7 @@ require (
 	go4.org/mem v0.0.0-20240501181205-ae6ca9944745 // indirect
 	go4.org/netipx v0.0.0-20231129151722-fdeea329fbba // indirect
 	golang.org/x/image v0.27.0 // indirect
-	golang.org/x/oauth2 v0.34.0 // indirect
-	golang.org/x/term v0.39.0 // indirect
+	golang.org/x/term v0.40.0 // indirect
 	golang.zx2c4.com/wintun v0.0.0-20230126152724-0fa3db229ce2 // indirect
 	golang.zx2c4.com/wireguard/windows v0.5.3 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
@@ -148,14 +149,14 @@ require (
 	go.opentelemetry.io/otel/metric v1.40.0 // indirect
 	go.opentelemetry.io/proto/otlp v1.9.0 // indirect
 	golang.org/x/arch v0.0.0-20210923205945-b76863e36670 // indirect
-	golang.org/x/crypto v0.47.0 // indirect
+	golang.org/x/crypto v0.48.0 // indirect
 	golang.org/x/exp v0.0.0-20251023183803-a4bb9ffd2546 // indirect
-	golang.org/x/net v0.49.0
+	golang.org/x/net v0.50.0
 	golang.org/x/sync v0.19.0
-	golang.org/x/sys v0.40.0 // indirect
-	golang.org/x/text v0.33.0 // indirect
+	golang.org/x/sys v0.41.0 // indirect
+	golang.org/x/text v0.34.0 // indirect
 	google.golang.org/genproto/googleapis/api v0.0.0-20260128011058-8636f8732409 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20260128011058-8636f8732409 // indirect
-	google.golang.org/grpc v1.78.0 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20260217215200-42d3e9bedb6d // indirect
+	google.golang.org/grpc v1.79.1 // indirect
 	google.golang.org/protobuf v1.36.11 // indirect
 )

go.sum

@@ -1,5 +1,7 @@
 9fans.net/go v0.0.8-0.20250307142834-96bdba94b63f h1:1C7nZuxUMNz7eiQALRfiqNOm04+m3edWlRff/BYHf0Q=
 9fans.net/go v0.0.8-0.20250307142834-96bdba94b63f/go.mod h1:hHyrZRryGqVdqrknjq5OWDLGCTJ2NeEvtrpR96mjraM=
+cloud.google.com/go/compute/metadata v0.9.0 h1:pDUj4QMoPejqq20dK0Pg2N4yG9zIkYGdBtwLoEkH9Zs=
+cloud.google.com/go/compute/metadata v0.9.0/go.mod h1:E0bWwX5wTnLPedCKqk3pJmVgCBSM6qQI1yTBdEb3C10=
 filippo.io/edwards25519 v1.1.0 h1:FNf4tywRC1HmFuKW5xopWpigGjJKiJSV0Cqo0cJWDaA=
 filippo.io/edwards25519 v1.1.0/go.mod h1:BxyFTGdWcka3PhytdK4V28tE5sGfRvvvRV7EaN4VDT4=
 filippo.io/mkcert v1.4.4 h1:8eVbbwfVlaqUM7OwuftKc2nuYOoTDQWqsoXmzoXZdbc=
@@ -451,43 +453,43 @@ go4.org/netipx v0.0.0-20231129151722-fdeea329fbba/go.mod h1:PLyyIXexvUFg3Owu6p/W
 golang.org/x/arch v0.0.0-20210923205945-b76863e36670 h1:18EFjUmQOcUvxNYSkA6jO9VAiXCnxFY6NyDX0bHDmkU=
 golang.org/x/arch v0.0.0-20210923205945-b76863e36670/go.mod h1:5om86z9Hs0C8fWVUuoMHwpExlXzs5Tkyp9hOrfG7pp8=
 golang.org/x/crypto v0.0.0-20210421170649-83a5a9bb288b/go.mod h1:T9bdIzuCu7OtxOm1hfPfRQxPLYneinmdGuTeoZ9dtd4=
-golang.org/x/crypto v0.47.0 h1:V6e3FRj+n4dbpw86FJ8Fv7XVOql7TEwpHapKoMJ/GO8=
-golang.org/x/crypto v0.47.0/go.mod h1:ff3Y9VzzKbwSSEzWqJsJVBnWmRwRSHt/6Op5n9bQc4A=
+golang.org/x/crypto v0.48.0 h1:/VRzVqiRSggnhY7gNRxPauEQ5Drw9haKdM0jqfcCFts=
+golang.org/x/crypto v0.48.0/go.mod h1:r0kV5h3qnFPlQnBSrULhlsRfryS2pmewsg+XfMgkVos=
 golang.org/x/exp v0.0.0-20251023183803-a4bb9ffd2546 h1:mgKeJMpvi0yx/sU5GsxQ7p6s2wtOnGAHZWCHUM4KGzY=
 golang.org/x/exp v0.0.0-20251023183803-a4bb9ffd2546/go.mod h1:j/pmGrbnkbPtQfxEe5D0VQhZC6qKbfKifgD0oM7sR70=
 golang.org/x/exp/typeparams v0.0.0-20240314144324-c7f7c6466f7f h1:phY1HzDcf18Aq9A8KkmRtY9WvOFIxN8wgfvy6Zm1DV8=
 golang.org/x/exp/typeparams v0.0.0-20240314144324-c7f7c6466f7f/go.mod h1:AbB0pIl9nAr9wVwH+Z2ZpaocVmF5I4GyWCDIsVjR0bk=
 golang.org/x/image v0.0.0-20191009234506-e7c1f5e7dbb8/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/image v0.27.0 h1:C8gA4oWU/tKkdCfYT6T2u4faJu3MeNS5O8UPWlPF61w=
 golang.org/x/image v0.27.0/go.mod h1:xbdrClrAUway1MUTEZDq9mz/UpRwYAkFFNUslZtcB+g=
-golang.org/x/mod v0.31.0 h1:HaW9xtz0+kOcWKwli0ZXy79Ix+UW/vOfmWI5QVd2tgI=
-golang.org/x/mod v0.31.0/go.mod h1:43JraMp9cGx1Rx3AqioxrbrhNsLl2l/iNAvuBkrezpg=
+golang.org/x/mod v0.32.0 h1:9F4d3PHLljb6x//jOyokMv3eX+YDeepZSEo3mFJy93c=
+golang.org/x/mod v0.32.0/go.mod h1:SgipZ/3h2Ci89DlEtEXWUk/HteuRin+HHhN+WbNhguU=
 golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
-golang.org/x/net v0.49.0 h1:eeHFmOGUTtaaPSGNmjBKpbng9MulQsJURQUAfUwY++o=
-golang.org/x/net v0.49.0/go.mod h1:/ysNB2EvaqvesRkuLAyjI1ycPZlQHM3q01F02UY/MV8=
-golang.org/x/oauth2 v0.34.0 h1:hqK/t4AKgbqWkdkcAeI8XLmbK+4m4G5YeQRrmiotGlw=
-golang.org/x/oauth2 v0.34.0/go.mod h1:lzm5WQJQwKZ3nwavOZ3IS5Aulzxi68dUSgRHujetwEA=
+golang.org/x/net v0.50.0 h1:ucWh9eiCGyDR3vtzso0WMQinm2Dnt8cFMuQa9K33J60=
+golang.org/x/net v0.50.0/go.mod h1:UgoSli3F/pBgdJBHCTc+tp3gmrU4XswgGRgtnwWTfyM=
+golang.org/x/oauth2 v0.35.0 h1:Mv2mzuHuZuY2+bkyWXIHMfhNdJAdwW3FuWeCPYN5GVQ=
+golang.org/x/oauth2 v0.35.0/go.mod h1:lzm5WQJQwKZ3nwavOZ3IS5Aulzxi68dUSgRHujetwEA=
 golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.19.0 h1:vV+1eWNmZ5geRlYjzm2adRgW2/mcpevXNg50YZtPCE4=
 golang.org/x/sync v0.19.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210809222454-d867a43fc93e/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220817070843-5a390386f1f2/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.40.0 h1:DBZZqJ2Rkml6QMQsZywtnjnnGvHza6BTfYFWY9kjEWQ=
-golang.org/x/sys v0.40.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/sys v0.41.0 h1:Ivj+2Cp/ylzLiEU89QhWblYnOE9zerudt9Ftecq2C6k=
+golang.org/x/sys v0.41.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
-golang.org/x/term v0.39.0 h1:RclSuaJf32jOqZz74CkPA9qFuVTX7vhLlpfj/IGWlqY=
-golang.org/x/term v0.39.0/go.mod h1:yxzUCTP/U+FzoxfdKmLaA0RV1WgE0VY7hXBwKtY/4ww=
+golang.org/x/term v0.40.0 h1:36e4zGLqU4yhjlmxEaagx2KuYbJq3EwY8K943ZsHcvg=
+golang.org/x/term v0.40.0/go.mod h1:w2P8uVp06p2iyKKuvXIm7N/y0UCRt3UfJTfZ7oOpglM=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
-golang.org/x/text v0.33.0 h1:B3njUFyqtHDUI5jMn1YIr5B0IE2U0qck04r6d4KPAxE=
-golang.org/x/text v0.33.0/go.mod h1:LuMebE6+rBincTi9+xWTY8TztLzKHc/9C1uBCG27+q8=
+golang.org/x/text v0.34.0 h1:oL/Qq0Kdaqxa1KbNeMKwQq0reLCCaFtqu2eNuSeNHbk=
+golang.org/x/text v0.34.0/go.mod h1:homfLqTYRFyVYemLBFl5GgL/DWEiH5wcsQ5gSh1yziA=
 golang.org/x/time v0.14.0 h1:MRx4UaLrDotUKUdCIqzPC48t1Y9hANFKIRpNx+Te8PI=
 golang.org/x/time v0.14.0/go.mod h1:eL/Oa2bBBK0TkX57Fyni+NgnyQQN4LitPmob2Hjnqw4=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
-golang.org/x/tools v0.40.0 h1:yLkxfA+Qnul4cs9QA3KnlFu0lVmd8JJfoq+E41uSutA=
-golang.org/x/tools v0.40.0/go.mod h1:Ik/tzLRlbscWpqqMRjyWYDisX8bG13FrdXp3o4Sr9lc=
+golang.org/x/tools v0.41.0 h1:a9b8iMweWG+S0OBnlU36rzLp20z1Rp10w+IY2czHTQc=
+golang.org/x/tools v0.41.0/go.mod h1:XSY6eDqxVNiYgezAVqqCeihT4j1U2CCsqvH3WhQpnlg=
 golang.zx2c4.com/wintun v0.0.0-20230126152724-0fa3db229ce2 h1:B82qJJgjvYKsXS9jeunTOisW56dUokqW/FOteYJJ/yg=
 golang.zx2c4.com/wintun v0.0.0-20230126152724-0fa3db229ce2/go.mod h1:deeaetjYA+DHMHg+sMSMI58GrEteJUUzzw7en6TJQcI=
 golang.zx2c4.com/wireguard/windows v0.5.3 h1:On6j2Rpn3OEMXqBq00QEDC7bWSZrPIHKIus8eIuExIE=
@@ -496,10 +498,10 @@ gonum.org/v1/gonum v0.16.0 h1:5+ul4Swaf3ESvrOnidPp4GZbzf0mxVQpDCYUQE7OJfk=
 gonum.org/v1/gonum v0.16.0/go.mod h1:fef3am4MQ93R2HHpKnLk4/Tbh/s0+wqD5nfa6Pnwy4E=
 google.golang.org/genproto/googleapis/api v0.0.0-20260128011058-8636f8732409 h1:merA0rdPeUV3YIIfHHcH4qBkiQAc1nfCKSI7lB4cV2M=
 google.golang.org/genproto/googleapis/api v0.0.0-20260128011058-8636f8732409/go.mod h1:fl8J1IvUjCilwZzQowmw2b7HQB2eAuYBabMXzWurF+I=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20260128011058-8636f8732409 h1:H86B94AW+VfJWDqFeEbBPhEtHzJwJfTbgE2lZa54ZAQ=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20260128011058-8636f8732409/go.mod h1:j9x/tPzZkyxcgEFkiKEEGxfvyumM01BEtsW8xzOahRQ=
-google.golang.org/grpc v1.78.0 h1:K1XZG/yGDJnzMdd/uZHAkVqJE+xIDOcmdSFZkBUicNc=
-google.golang.org/grpc v1.78.0/go.mod h1:I47qjTo4OKbMkjA/aOOwxDIiPSBofUtQUI5EfpWvW7U=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20260217215200-42d3e9bedb6d h1:t/LOSXPJ9R0B6fnZNyALBRfZBH0Uy0gT+uR+SJ6syqQ=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20260217215200-42d3e9bedb6d/go.mod h1:4Hqkh8ycfw05ld/3BWL7rJOSfebL2Q+DVDeRgYgxUU8=
+google.golang.org/grpc v1.79.1 h1:zGhSi45ODB9/p3VAawt9a+O/MULLl9dpizzNNpq7flY=
+google.golang.org/grpc v1.79.1/go.mod h1:KmT0Kjez+0dde/v2j9vzwoAScgEPx/Bw1CYChhHLrHQ=
 google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
 google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

internal/channels/channel.go

@@ -58,6 +58,7 @@ const (
 	TypeWhatsApp     = "whatsapp"
 	TypeZaloOA       = "zalo_oa"
 	TypeZaloPersonal = "zalo_personal"
+	TypeGoogleChat   = "google_chat"
 )
 
 // Channel defines the interface that all channel implementations must satisfy.

internal/channels/googlechat/api.go

@@ -0,0 +1,117 @@
+package googlechat
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+
+	"golang.org/x/oauth2"
+	"golang.org/x/oauth2/google"
+)
+
+const (
+	chatAPIBase = "https://chat.googleapis.com/v1/"
+	chatScope   = "https://www.googleapis.com/auth/chat.bot"
+)
+
+// ChatClient is a lightweight Google Chat REST API client.
+type ChatClient struct {
+	httpClient  *http.Client
+	tokenSource oauth2.TokenSource
+}
+
+// NewChatClient creates a client authenticated via Service Account JSON content.
+func NewChatClient(saJSON []byte) (*ChatClient, error) {
+	conf, err := google.JWTConfigFromJSON(saJSON, chatScope)
+	if err != nil {
+		return nil, fmt.Errorf("parse service account: %w", err)
+	}
+
+	ts := conf.TokenSource(context.Background())
+
+	return &ChatClient{
+		httpClient:  &http.Client{Timeout: 30 * time.Second},
+		tokenSource: ts,
+	}, nil
+}
+
+// doJSON performs an authenticated JSON request to the Google Chat API.
+func (c *ChatClient) doJSON(ctx context.Context, method, url string, body interface{}) ([]byte, error) {
+	var bodyReader io.Reader
+	if body != nil {
+		data, err := json.Marshal(body)
+		if err != nil {
+			return nil, fmt.Errorf("marshal body: %w", err)
+		}
+		bodyReader = bytes.NewReader(data)
+	}
+
+	req, err := http.NewRequestWithContext(ctx, method, url, bodyReader)
+	if err != nil {
+		return nil, err
+	}
+
+	token, err := c.tokenSource.Token()
+	if err != nil {
+		return nil, fmt.Errorf("get token: %w", err)
+	}
+	req.Header.Set("Authorization", "Bearer "+token.AccessToken)
+	if body != nil {
+		req.Header.Set("Content-Type", "application/json")
+	}
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("google chat api %s: %w", method, err)
+	}
+	defer resp.Body.Close()
+
+	respBody, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("read response body: %w", err)
+	}
+	if resp.StatusCode >= 400 {
+		return nil, fmt.Errorf("google chat api %d: %s", resp.StatusCode, string(respBody))
+	}
+	return respBody, nil
+}
+
+// SendMessage sends a text message to a Google Chat space.
+// spaceName format: "spaces/SPACE_ID"
+func (c *ChatClient) SendMessage(ctx context.Context, spaceName, text string) error {
+	url := chatAPIBase + spaceName + "/messages"
+	msg := gcSendMessage{Text: text}
+	_, err := c.doJSON(ctx, "POST", url, msg)
+	return err
+}
+
+// AddReaction adds an emoji reaction to a message.
+// messageName format: "spaces/SPACE_ID/messages/MSG_ID"
+// Returns the reaction resource name for deletion.
+func (c *ChatClient) AddReaction(ctx context.Context, messageName, unicode string) (string, error) {
+	url := chatAPIBase + messageName + "/reactions"
+	body := gcReaction{Emoji: &gcEmoji{Unicode: unicode}}
+	respBody, err := c.doJSON(ctx, "POST", url, body)
+	if err != nil {
+		return "", err
+	}
+	var result struct {
+		Name string `json:"name"`
+	}
+	if err := json.Unmarshal(respBody, &result); err != nil {
+		return "", fmt.Errorf("parse reaction response: %w", err)
+	}
+	return result.Name, nil
+}
+
+// DeleteReaction removes a reaction from a message.
+// reactionName format: "spaces/SPACE_ID/messages/MSG_ID/reactions/REACTION_ID"
+func (c *ChatClient) DeleteReaction(ctx context.Context, reactionName string) error {
+	url := chatAPIBase + reactionName
+	_, err := c.doJSON(ctx, "DELETE", url, nil)
+	return err
+}