feat: add Claude Opus 4.5 (#121)

Co-authored-by: Charles Packer <packercharles@gmail.com>

README.md

@@ -152,7 +152,7 @@ letta -p "Use the custom skills" --skills ~/my-skills
 letta                    # Auto-resume project agent (or create new if first time)
 letta --new              # Create new agent with new memory blocks
 letta --agent <id>       # Use specific agent ID
-letta --model <model>    # Specify model (e.g., claude-sonnet-4.5, gpt-4o)
+letta --model <model>    # Specify model (e.g., claude-opus-4.5, claude-sonnet-4.5, gpt-4o)
 letta -m <model>         # Short form of --model
 letta --continue         # Resume global last agent (deprecated, use project-based)
 

src/agent/model.ts

@@ -7,7 +7,7 @@ export const models = modelsData;
 
 /**
  * Resolve a model by ID or handle
- * @param modelIdentifier - Can be either a model ID (e.g., "opus") or a full handle (e.g., "anthropic/claude-opus-4-1-20250805")
+ * @param modelIdentifier - Can be either a model ID (e.g., "opus-4.5") or a full handle (e.g., "anthropic/claude-opus-4-5")
  * @returns The model handle if found, null otherwise
  */
 export function resolveModel(modelIdentifier: string): string | null {
@@ -43,7 +43,7 @@ export function formatAvailableModels(): string {
 
 /**
  * Get model info by ID or handle
- * @param modelIdentifier - Can be either a model ID (e.g., "opus") or a full handle (e.g., "anthropic/claude-opus-4-1-20250805")
+ * @param modelIdentifier - Can be either a model ID (e.g., "opus-4.5") or a full handle (e.g., "anthropic/claude-opus-4-5")
  * @returns The model info if found, null otherwise
  */
 export function getModelInfo(modelIdentifier: string) {
@@ -58,7 +58,7 @@ export function getModelInfo(modelIdentifier: string) {
 
 /**
  * Get updateArgs for a model by ID or handle
- * @param modelIdentifier - Can be either a model ID (e.g., "opus") or a full handle (e.g., "anthropic/claude-opus-4-1-20250805")
+ * @param modelIdentifier - Can be either a model ID (e.g., "opus-4.5") or a full handle (e.g., "anthropic/claude-opus-4-5")
  * @returns The updateArgs if found, undefined otherwise
  */
 export function getModelUpdateArgs(

src/index.ts

@@ -30,7 +30,7 @@ OPTIONS
   --fresh-blocks        Force create all new memory blocks (isolate from other agents)
   -c, --continue        Resume previous session (uses global lastAgent, deprecated)
   -a, --agent <id>      Use a specific agent ID
-  -m, --model <id>      Model ID or handle (e.g., "opus" or "anthropic/claude-opus-4-1-20250805")
+  -m, --model <id>      Model ID or handle (e.g., "opus-4.5" or "anthropic/claude-opus-4-5")
   --toolset <name>      Force toolset: "codex", "default", or "gemini" (overrides model-based auto-selection)
   -p, --prompt          Headless prompt mode
   --output-format <fmt> Output format for headless mode (text, json, stream-json)

src/models.json

@@ -22,7 +22,14 @@
     "id": "opus",
     "handle": "anthropic/claude-opus-4-1-20250805",
     "label": "Claude Opus 4.1",
-    "description": "Anthropic's largest (and slowest) model",
+    "description": "Anthropic's previous version of Opus",
+    "updateArgs": { "context_window": 180000 }
+  },
+  {
+    "id": "opus-4.5",
+    "handle": "anthropic/claude-opus-4-5-20251101",
+    "label": "Claude Opus 4.5",
+    "description": "Anthropic's newest flagship Opus 4.5 model",
     "isFeatured": true,
     "updateArgs": { "context_window": 180000 }
   },