feat(server): infer commit and PR title style from repo history

apps/server/src/git/Layers/ClaudeTextGeneration.ts

@@ -214,6 +214,7 @@ const makeClaudeTextGeneration = Effect.gen(function* () {
       stagedSummary: input.stagedSummary,
       stagedPatch: input.stagedPatch,
       includeBranch: input.includeBranch === true,
+      styleGuidance: input.styleGuidance,
     });
 
     if (input.modelSelection.provider !== "claudeAgent") {
@@ -249,6 +250,8 @@ const makeClaudeTextGeneration = Effect.gen(function* () {
       commitSummary: input.commitSummary,
       diffSummary: input.diffSummary,
       diffPatch: input.diffPatch,
+      styleGuidance: input.styleGuidance,
+      useDefaultTemplate: input.useDefaultTemplate,
     });
 
     if (input.modelSelection.provider !== "claudeAgent") {

apps/server/src/git/Layers/CodexTextGeneration.test.ts

@@ -14,15 +14,18 @@ const DEFAULT_TEST_MODEL_SELECTION = {
   model: "gpt-5.4-mini",
 };
 
-const CodexTextGenerationTestLayer = CodexTextGenerationLive.pipe(
-  Layer.provideMerge(ServerSettingsService.layerTest()),
-  Layer.provideMerge(
-    ServerConfig.layerTest(process.cwd(), {
-      prefix: "t3code-codex-text-generation-test-",
-    }),
-  ),
-  Layer.provideMerge(NodeServices.layer),
-);
+const makeCodexTextGenerationTestLayer = () =>
+  CodexTextGenerationLive.pipe(
+    Layer.provideMerge(ServerSettingsService.layerTest()),
+    Layer.provideMerge(
+      ServerConfig.layerTest(process.cwd(), {
+        prefix: "t3code-codex-text-generation-test-",
+      }),
+    ),
+    Layer.provideMerge(NodeServices.layer),
+  );
+
+const CodexTextGenerationTestLayer = makeCodexTextGenerationTestLayer();
 
 function makeFakeCodexBinary(
   dir: string,
@@ -223,6 +226,33 @@ it.layer(CodexTextGenerationTestLayer)("CodexTextGenerationLive", (it) => {
     ),
   );
 
+  it.effect("includes provided commit style guidance in the codex prompt", () =>
+    withFakeCodexEnv(
+      {
+        output: JSON.stringify({
+          subject: "feat: add commit style guidance",
+          body: "",
+        }),
+        stdinMustContain: "Current author's recent commit subjects:",
+      },
+      Effect.gen(function* () {
+        const textGeneration = yield* TextGeneration;
+
+        const generated = yield* textGeneration.generateCommitMessage({
+          cwd: process.cwd(),
+          branch: "feature/default-commit-style",
+          stagedSummary: "M README.md",
+          stagedPatch: "diff --git a/README.md b/README.md",
+          styleGuidance:
+            "Commit style guidance:\n- Prefer the current author's own recent commit style when examples are available.\nCurrent author's recent commit subjects:\n- feat: add commit style guidance",
+          modelSelection: DEFAULT_TEST_MODEL_SELECTION,
+        });
+
+        expect(generated.subject).toBe("feat: add commit style guidance");
+      }),
+    ),
+  );
+
   it.effect(
     "forwards codex fast mode and non-default reasoning effort into codex exec config",
     () =>
@@ -279,7 +309,6 @@ it.layer(CodexTextGenerationTestLayer)("CodexTextGenerationLive", (it) => {
       }),
     ),
   );
-
   it.effect("generates commit message with branch when includeBranch is true", () =>
     withFakeCodexEnv(
       {
@@ -336,6 +365,36 @@ it.layer(CodexTextGenerationTestLayer)("CodexTextGenerationLive", (it) => {
     ),
   );
 
+  it.effect("includes provided PR style guidance while keeping the default template", () =>
+    withFakeCodexEnv(
+      {
+        output: JSON.stringify({
+          title: "feat: add repo style guidance",
+          body: "\n## Summary\n- add guidance\n\n## Testing\n- Not run\n",
+        }),
+        stdinMustContain: "Default the PR title to Conventional Commits: type(scope): summary",
+      },
+      Effect.gen(function* () {
+        const textGeneration = yield* TextGeneration;
+
+        const generated = yield* textGeneration.generatePrContent({
+          cwd: process.cwd(),
+          baseBranch: "main",
+          headBranch: "feature/repo-style-guidance",
+          commitSummary: "feat: add repo style guidance",
+          diffSummary: "2 files changed",
+          diffPatch: "diff --git a/a.ts b/a.ts",
+          styleGuidance:
+            "PR style guidance:\n- No recent pull request examples are available from this author or repository.\n- Default the PR title to Conventional Commits: type(scope): summary",
+          useDefaultTemplate: true,
+          modelSelection: DEFAULT_TEST_MODEL_SELECTION,
+        });
+
+        expect(generated.title).toBe("feat: add repo style guidance");
+      }),
+    ),
+  );
+
   it.effect("generates branch names and normalizes branch fragments", () =>
     withFakeCodexEnv(
       {
@@ -635,3 +694,65 @@ it.layer(CodexTextGenerationTestLayer)("CodexTextGenerationLive", (it) => {
     ),
   );
 });
+
+it.layer(CodexTextGenerationTestLayer)("CodexTextGenerationLive commit style examples", (it) => {
+  it.effect("includes recent commit subjects in commit prompt style guidance", () =>
+    withFakeCodexEnv(
+      {
+        output: JSON.stringify({
+          subject: "fix(web): patch sidebar focus ring",
+          body: "",
+        }),
+        stdinMustContain: "fix(web): patch sidebar focus ring",
+      },
+      Effect.gen(function* () {
+        const textGeneration = yield* TextGeneration;
+
+        const generated = yield* textGeneration.generateCommitMessage({
+          cwd: process.cwd(),
+          branch: "feature/style-guidance",
+          stagedSummary: "M sidebar.tsx",
+          stagedPatch: "diff --git a/sidebar.tsx b/sidebar.tsx",
+          styleGuidance:
+            "Commit style guidance:\n- Prefer the current author's own recent commit style when examples are available.\nCurrent author's recent commit subjects:\n- fix(web): patch sidebar focus ring\n- Add compact chat timeline icons",
+          modelSelection: DEFAULT_TEST_MODEL_SELECTION,
+        });
+
+        expect(generated.subject).toBe("fix(web): patch sidebar focus ring");
+      }),
+    ),
+  );
+});
+
+it.layer(CodexTextGenerationTestLayer)("CodexTextGenerationLive PR title examples", (it) => {
+  it.effect("includes recent PR examples in pull request prompt style guidance", () =>
+    withFakeCodexEnv(
+      {
+        output: JSON.stringify({
+          title: "Add customizable worktree branch naming",
+          body: "\nJust say what changed.\n",
+        }),
+        stdinMustContain: "Add customizable worktree branch naming",
+        stdinMustNotContain: "include headings '## Summary' and '## Testing'",
+      },
+      Effect.gen(function* () {
+        const textGeneration = yield* TextGeneration;
+
+        const generated = yield* textGeneration.generatePrContent({
+          cwd: process.cwd(),
+          baseBranch: "main",
+          headBranch: "feature/worktree-names",
+          commitSummary: "feat: add command palette",
+          diffSummary: "2 files changed",
+          diffPatch: "diff --git a/a.ts b/a.ts",
+          styleGuidance:
+            "PR style guidance:\n- Prefer the current author's own recent pull request style when examples are available.\nCurrent author's recent pull requests:\n1. Title: Add customizable worktree branch naming\n   Body:\nJust say what changed.",
+          useDefaultTemplate: false,
+          modelSelection: DEFAULT_TEST_MODEL_SELECTION,
+        });
+
+        expect(generated.title).toBe("Add customizable worktree branch naming");
+      }),
+    ),
+  );
+});

apps/server/src/git/Layers/CodexTextGeneration.ts

@@ -3,37 +3,37 @@ import { randomUUID } from "node:crypto";
 import { Effect, FileSystem, Layer, Option, Path, Schema, Scope, Stream } from "effect";
 import { ChildProcess, ChildProcessSpawner } from "effect/unstable/process";
 
-import { CodexModelSelection } from "@t3tools/contracts";
+import { CodexModelSelection, TextGenerationError } from "@t3tools/contracts";
+import { normalizeCodexModelOptionsWithCapabilities } from "@t3tools/shared/model";
 import { sanitizeBranchFragment, sanitizeFeatureBranchName } from "@t3tools/shared/git";
 
 import { resolveAttachmentPath } from "../../attachmentStore.ts";
 import { ServerConfig } from "../../config.ts";
-import { TextGenerationError } from "@t3tools/contracts";
-import {
-  type BranchNameGenerationInput,
-  type ThreadTitleGenerationResult,
-  type TextGenerationShape,
-  TextGeneration,
-} from "../Services/TextGeneration.ts";
+import { getCodexModelCapabilities } from "../../provider/Layers/CodexProvider.ts";
+import { ServerSettingsService } from "../../serverSettings.ts";
 import {
   buildBranchNamePrompt,
   buildCommitMessagePrompt,
   buildPrContentPrompt,
   buildThreadTitlePrompt,
 } from "../Prompts.ts";
+import {
+  type BranchNameGenerationInput,
+  type TextGenerationShape,
+  type ThreadTitleGenerationResult,
+  TextGeneration,
+} from "../Services/TextGeneration.ts";
 import {
   normalizeCliError,
   sanitizeCommitSubject,
   sanitizePrTitle,
   sanitizeThreadTitle,
   toJsonSchemaObject,
 } from "../Utils.ts";
-import { getCodexModelCapabilities } from "../../provider/Layers/CodexProvider.ts";
-import { ServerSettingsService } from "../../serverSettings.ts";
-import { normalizeCodexModelOptionsWithCapabilities } from "@t3tools/shared/model";
 
 const CODEX_GIT_TEXT_GENERATION_REASONING_EFFORT = "low";
 const CODEX_TIMEOUT_MS = 180_000;
+
 const makeCodexTextGeneration = Effect.gen(function* () {
   const fileSystem = yield* FileSystem.FileSystem;
   const path = yield* Path.Path;
@@ -276,20 +276,21 @@ const makeCodexTextGeneration = Effect.gen(function* () {
   const generateCommitMessage: TextGenerationShape["generateCommitMessage"] = Effect.fn(
     "CodexTextGeneration.generateCommitMessage",
   )(function* (input) {
-    const { prompt, outputSchema } = buildCommitMessagePrompt({
-      branch: input.branch,
-      stagedSummary: input.stagedSummary,
-      stagedPatch: input.stagedPatch,
-      includeBranch: input.includeBranch === true,
-    });
-
     if (input.modelSelection.provider !== "codex") {
       return yield* new TextGenerationError({
         operation: "generateCommitMessage",
         detail: "Invalid model selection.",
       });
     }
 
+    const { prompt, outputSchema } = buildCommitMessagePrompt({
+      branch: input.branch,
+      stagedSummary: input.stagedSummary,
+      stagedPatch: input.stagedPatch,
+      includeBranch: input.includeBranch === true,
+      styleGuidance: input.styleGuidance,
+    });
+
     const generated = yield* runCodexJson({
       operation: "generateCommitMessage",
       cwd: input.cwd,
@@ -310,21 +311,23 @@ const makeCodexTextGeneration = Effect.gen(function* () {
   const generatePrContent: TextGenerationShape["generatePrContent"] = Effect.fn(
     "CodexTextGeneration.generatePrContent",
   )(function* (input) {
+    if (input.modelSelection.provider !== "codex") {
+      return yield* new TextGenerationError({
+        operation: "generatePrContent",
+        detail: "Invalid model selection.",
+      });
+    }
+
     const { prompt, outputSchema } = buildPrContentPrompt({
       baseBranch: input.baseBranch,
       headBranch: input.headBranch,
       commitSummary: input.commitSummary,
       diffSummary: input.diffSummary,
       diffPatch: input.diffPatch,
+      styleGuidance: input.styleGuidance,
+      useDefaultTemplate: input.useDefaultTemplate,
     });
 
-    if (input.modelSelection.provider !== "codex") {
-      return yield* new TextGenerationError({
-        operation: "generatePrContent",
-        detail: "Invalid model selection.",
-      });
-    }
-
     const generated = yield* runCodexJson({
       operation: "generatePrContent",
       cwd: input.cwd,

apps/server/src/git/Layers/GitCore.test.ts

@@ -2147,6 +2147,84 @@ it.layer(TestLayer)("git integration", (it) => {
       }),
     );
 
+    it.effect("reads recent commit subjects from repository history", () =>
+      Effect.gen(function* () {
+        const tmp = yield* makeTmpDir();
+        yield* initRepoWithCommit(tmp);
+        yield* commitWithDate(
+          tmp,
+          "feature.txt",
+          "feature one\n",
+          "2024-01-01T12:00:00Z",
+          "feat: add feature one",
+        );
+        yield* commitWithDate(
+          tmp,
+          "bugfix.txt",
+          "bugfix\n",
+          "2024-01-02T12:00:00Z",
+          "fix(web): patch regression",
+        );
+
+        const core = yield* GitCore;
+        const subjects = yield* core.readRecentCommitSubjects({
+          cwd: tmp,
+          limit: 2,
+        });
+
+        expect(subjects).toEqual(["fix(web): patch regression", "feat: add feature one"]);
+      }),
+    );
+
+    it.effect("returns an empty recent commit subject list for a repo with no commits yet", () =>
+      Effect.gen(function* () {
+        const tmp = yield* makeTmpDir();
+        const core = yield* GitCore;
+        yield* core.initRepo({ cwd: tmp });
+
+        const subjects = yield* core.readRecentCommitSubjects({
+          cwd: tmp,
+          limit: 5,
+        });
+
+        expect(subjects).toEqual([]);
+      }),
+    );
+
+    it.effect("filters recent commit subjects by exact author identity across all refs", () =>
+      Effect.gen(function* () {
+        const tmp = yield* makeTmpDir();
+        yield* initRepoWithCommit(tmp);
+        yield* git(tmp, ["config", "user.email", "me.name@example.com"]);
+        yield* git(tmp, ["config", "user.name", "Me Name"]);
+        yield* commitWithDate(
+          tmp,
+          "author.txt",
+          "author\n",
+          "2024-01-03T12:00:00Z",
+          "feat: author style",
+        );
+        yield* git(tmp, ["config", "user.email", "meXname@exampleYcom"]);
+        yield* git(tmp, ["config", "user.name", "False Positive"]);
+        yield* commitWithDate(
+          tmp,
+          "other.txt",
+          "other\n",
+          "2024-01-04T12:00:00Z",
+          "docs: regex false positive",
+        );
+
+        const core = yield* GitCore;
+        const subjects = yield* core.readRecentCommitSubjects({
+          cwd: tmp,
+          limit: 5,
+          author: "me.name@example.com",
+          scope: "allRefs",
+        });
+
+        expect(subjects).toEqual(["feat: author style"]);
+      }),
+    );
     it.effect("prepareCommitContext truncates oversized staged patches instead of failing", () =>
       Effect.gen(function* () {
         const tmp = yield* makeTmpDir();
@@ -2180,7 +2258,6 @@ it.layer(TestLayer)("git integration", (it) => {
         expect(rangeContext.diffPatch).toContain("[truncated]");
       }),
     );
-
     it.effect("pushes with upstream setup and then skips when up to date", () =>
       Effect.gen(function* () {
         const tmp = yield* makeTmpDir();