feat(campfires): add UpdateCampfireLine operation

AGENTS.md

@@ -4,7 +4,7 @@
 
 | Component | Status | Details |
 |-----------|--------|---------|
-| **Smithy Spec** | 175 operations | Single source of truth for all APIs |
+| **Smithy Spec** | 204 operations | Single source of truth for all APIs |
 | **Go SDK** | Production-ready | Full generated client + service wrappers |
 | **TypeScript SDK** | Production-ready | 37 generated services, openapi-fetch based |
 | **Ruby SDK** | Production-ready | 37 generated services |
@@ -31,7 +31,7 @@ Smithy Spec → OpenAPI → Generated Client → Service Layer → User
 | **Kotlin** | Ktor via `BaseService` | `sdk/src/commonMain/kotlin/.../generated/services/*.kt` |
 | **Python** | httpx via `HttpClient` | `src/basecamp/generated/services/*.py` |
 
-All 175 operations across 38+ services are generated. Hand-written code is limited to infrastructure:
+All 204 operations across 38+ services are generated. Hand-written code is limited to infrastructure:
 
 | Purpose | TypeScript | Ruby | Swift | Kotlin | Python |
 |---------|-----------|------|-------|--------|--------|

SPEC.md

@@ -496,7 +496,7 @@ END
 
 ### behavior-model.json Retry Patterns
 
-All 181 operations in `behavior-model.json` use `retry_on: [429, 503]`. Three `(max, base_delay_ms)` patterns exist:
+All 204 operations in `behavior-model.json` use `retry_on: [429, 503]`. Three `(max, base_delay_ms)` patterns exist:
 - `(2, 1000)` — most create operations
 - `(3, 1000)` — most read/update/delete operations
 - `(3, 2000)` — `CreateAttachment`, `CreateCampfireUpload` (file uploads)
@@ -1504,9 +1504,9 @@ Every operation has a `retry` block, including non-idempotent POSTs. For non-ide
 
 ### Operation Counts
 
-- Total operations: 181
-- Idempotent: 55 (flagged with `idempotent: true`)
-- Non-idempotent: 126 (no `idempotent` field, or not present)
+- Total operations: 204
+- Idempotent: 66 (flagged with `idempotent: true`)
+- Non-idempotent: 138 (no `idempotent` field, or not present)
 - All operations use `retry_on: [429, 503]`
 
 ---

behavior-model.json

@@ -2257,6 +2257,18 @@
         ]
       }
     },
+    "UpdateCampfireLine": {
+      "idempotent": true,
+      "retry": {
+        "max": 3,
+        "base_delay_ms": 1000,
+        "backoff": "exponential",
+        "retry_on": [
+          429,
+          503
+        ]
+      }
+    },
     "UpdateCard": {
       "idempotent": true,
       "retry": {

go/README.md

@@ -228,7 +228,7 @@ cfg, err := basecamp.LoadConfig("/path/to/config.json")
 | `MessageBoards()` | Get |
 | `MessageTypes()` | List, Get, Create, Update, Destroy |
 | `Comments()` | List, Get, Create, Update, Trash |
-| `Campfires()` | List, Get, ListLines, GetLine, CreateLine, DeleteLine, Chatbot CRUD |
+| `Campfires()` | List, Get, ListLines, GetLine, CreateLine, UpdateLine, DeleteLine, Chatbot CRUD |
 | `Forwards()` | List, Get |
 
 ### Scheduling

go/pkg/basecamp/campfires.go

@@ -482,6 +482,44 @@ func (s *CampfiresService) CreateLine(ctx context.Context, campfireID int64, con
 	return &line, nil
 }
 
+// UpdateLine updates the content of an existing line (message) in a campfire.
+// The content is always treated as rich text (HTML) — the server coerces every
+// edited line to rich text — and only the line's creator may edit it.
+// The API returns 204 No Content on success; if the caller needs the updated
+// representation, follow up with GetLine. Mirrors DeleteLine in returning only
+// an error so a transient post-mutation read can't make a successful update
+// appear to fail.
+func (s *CampfiresService) UpdateLine(ctx context.Context, campfireID, lineID int64, content string) (err error) {
+	op := OperationInfo{
+		Service: "Campfires", Operation: "UpdateLine",
+		ResourceType: "campfire_line", IsMutation: true,
+		ResourceID: lineID,
+	}
+	if gater, ok := s.client.parent.hooks.(GatingHooks); ok {
+		if ctx, err = gater.OnOperationGate(ctx, op); err != nil {
+			return
+		}
+	}
+	start := time.Now()
+	ctx = s.client.parent.hooks.OnOperationStart(ctx, op)
+	defer func() { s.client.parent.hooks.OnOperationEnd(ctx, op, err, time.Since(start)) }()
+
+	if content == "" {
+		err = ErrUsage("campfire line content is required")
+		return err
+	}
+
+	body := generated.UpdateCampfireLineJSONRequestBody{
+		Content: content,
+	}
+
+	resp, err := s.client.parent.gen.UpdateCampfireLineWithResponse(ctx, s.client.accountID, campfireID, lineID, body)
+	if err != nil {
+		return err
+	}
+	return checkResponse(resp.HTTPResponse, resp.Body)
+}
+
 // DeleteLine deletes a line (message) from a campfire.
 func (s *CampfiresService) DeleteLine(ctx context.Context, campfireID, lineID int64) (err error) {
 	op := OperationInfo{

go/pkg/basecamp/campfires_test.go

@@ -663,6 +663,54 @@ func TestCreateLine_PlainOption_Service(t *testing.T) {
 	}
 }
 
+func TestUpdateLine_EmptyContent(t *testing.T) {
+	svc := testCampfiresServer(t, func(w http.ResponseWriter, r *http.Request) {
+		t.Errorf("server should not be called when content is empty")
+	})
+	if err := svc.UpdateLine(context.Background(), 200, 1069479350, ""); err == nil {
+		t.Fatalf("expected error for empty content")
+	}
+}
+
+func TestUpdateLine_Service(t *testing.T) {
+	var receivedBody map[string]any
+	var receivedMethod, receivedPath string
+	svc := testCampfiresServer(t, func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != "PUT" {
+			t.Errorf("expected PUT only, got %s", r.Method)
+			return
+		}
+		receivedMethod = r.Method
+		receivedPath = r.URL.Path
+		body, err := io.ReadAll(r.Body)
+		if err != nil {
+			t.Errorf("failed to read request body: %v", err)
+			return
+		}
+		if err := json.Unmarshal(body, &receivedBody); err != nil {
+			t.Errorf("failed to unmarshal request body: %v", err)
+			return
+		}
+		w.WriteHeader(204)
+	})
+
+	if err := svc.UpdateLine(context.Background(), 200, 1069479350, "Edited!"); err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if receivedMethod != "PUT" {
+		t.Errorf("expected PUT, got %s", receivedMethod)
+	}
+	if receivedPath != "/99999/chats/200/lines/1069479350" {
+		t.Errorf("unexpected path: %s", receivedPath)
+	}
+	if receivedBody["content"] != "Edited!" {
+		t.Errorf("expected content 'Edited!', got %v", receivedBody["content"])
+	}
+	if len(receivedBody) != 1 {
+		t.Errorf("expected body to contain only content, got %v", receivedBody)
+	}
+}
+
 func TestChatbot_UnmarshalList(t *testing.T) {
 	data := loadCampfiresFixture(t, "chatbots_list.json")
 

go/pkg/basecamp/url-routes.json

@@ -488,7 +488,8 @@
       "resource": "Campfire",
       "operations": {
         "DELETE": "DeleteCampfireLine",
-        "GET": "GetCampfireLine"
+        "GET": "GetCampfireLine",
+        "PUT": "UpdateCampfireLine"
       },
       "params": {
         "accountId": {