Fix extractFamily for o-series models

package.json

@@ -1,6 +1,6 @@
 {
   "name": "copilot-sdk-proxy",
-  "version": "1.0.1",
+  "version": "1.0.2",
   "description": "Generic proxy server translating OpenAI/Anthropic/Codex API requests into GitHub Copilot SDK sessions",
   "type": "module",
   "license": "MIT",

src/providers/shared/model-resolver.ts

@@ -7,13 +7,12 @@ function normalize(id: string): string {
   return id.replace(/-\d{8}$/, "").replace(/\./g, "-");
 }
 
-// We need to group models by family for fallback matching, so we grab the
-// prefix before the first digit (e.g. "claude-sonnet-4-5" becomes "claude-sonnet-").
-// This works for Claude naming but would lump all GPT models into "gpt-"
-// so it'll need reworking once we support non-Claude model families here
-// e.g. if we add Codex support.
+// Group models by family for fallback matching by grabbing everything before
+// the first digit (e.g. "claude-sonnet-4-5" becomes "claude-sonnet-",
+// "o3-mini" becomes "o", "gpt-5" becomes "gpt-"). The longest-prefix
+// matching within the family handles disambiguation.
 function extractFamily(id: string): string {
-  const match = id.match(/^(.*?-)\d/);
+  const match = id.match(/^(.*?)\d/);
   return match?.[1] ?? id;
 }
 

test/model-resolver.test.ts

@@ -20,6 +20,8 @@ const copilotModels = [
   "claude-sonnet-4.5",
   "gpt-5",
   "gpt-5.1",
+  "o3-mini",
+  "o4-mini",
 ].map(model);
 
 describe("resolveModel", () => {
@@ -80,6 +82,16 @@ describe("resolveModel", () => {
     );
   });
 
+  it("handles o-series models (exact match)", () => {
+    expect(resolveModel("o3-mini", copilotModels)).toBe("o3-mini");
+  });
+
+  it("falls back within o-series family", () => {
+    // o3 isn't available but o3-mini is, and they share the "o" family
+    // with o3-mini winning on longest prefix
+    expect(resolveModel("o3", copilotModels)).toBe("o3-mini");
+  });
+
   it("returns undefined for empty models array", () => {
     expect(resolveModel("claude-sonnet-4.5", [])).toBeUndefined();
   });