Decouple 42 files from @google/genai via Delta type barrel

[tjdoomer]

Summary

Creates packages/core/src/types/delta.ts as the single decoupling point from @google/genai. 42 files migrated from direct SDK imports to the Delta barrel — pure import path changes, zero logic changes.

What changed

• New types/delta.ts barrel re-exports all shared types (Content, Part, GenerateContentResponse, FunctionDeclaration, etc.)
• 42 non-provider files now import from ../types/delta.js instead of @google/genai
• 11 files intentionally keep direct @google/genai imports (provider adapters, factory, the barrel itself)

Why this matters

When we replace @google/genai types with native Delta definitions, only types/delta.ts changes — the other 42 files are completely unaffected. This is the foundation for supporting provider-specific features (Anthropic citations, OpenAI structured outputs) without being constrained by Google's type system.

Also includes

• Native DeltaModelCapabilities and DeltaProviderType types for features not representable in @google/genai

Test plan

• All 1873 tests pass
• Type-check clean
• Full workspace build clean
• Verified remaining direct imports are all intentional (provider-specific)

Summary by CodeRabbit

• New Features

  • Added DeltaModelCapabilities interface defining model capability properties (tool calling, vision, streaming, context window, and think blocks)
  • Added DeltaProviderType to enumerate supported AI provider identifiers

• Refactor

  • Created centralized Delta types module consolidating type definitions for improved consistency across the codebase

• Documentation

  • Added roadmap documentation outlining the Delta types refactoring strategy and implementation phases

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 1f618c60-e49a-4836-b704-1d3c2cf98cd1

📥 Commits

Reviewing files that changed from the base of the PR and between e27e0da and 34b21cc.

📒 Files selected for processing (43)

• docs/roadmap/05-delta-types.md
• packages/cli/src/nonInteractiveCli.ts
• packages/cli/src/ui/commands/types.ts
• packages/cli/src/ui/hooks/atCommandProcessor.ts
• packages/cli/src/ui/hooks/shellCommandProcessor.ts
• packages/cli/src/ui/hooks/slashCommandProcessor.ts
• packages/cli/src/ui/hooks/useDeltaStream.ts
• packages/cli/src/zed-integration/zedIntegration.ts
• packages/core/src/core/client.ts
• packages/core/src/core/coreToolScheduler.ts
• packages/core/src/core/deltaChat.ts
• packages/core/src/core/deltaRequest.ts
• packages/core/src/core/logger.ts
• packages/core/src/core/subagent.ts
• packages/core/src/core/turn.ts
• packages/core/src/telemetry/types.ts
• packages/core/src/test-utils/tools.ts
• packages/core/src/tools/checkpoint.ts
• packages/core/src/tools/diffPreview.ts
• packages/core/src/tools/fileSummary.ts
• packages/core/src/tools/lint.ts
• packages/core/src/tools/mcp-client.ts
• packages/core/src/tools/mcp-tool.ts
• packages/core/src/tools/memoryTool.ts
• packages/core/src/tools/multiEdit.ts
• packages/core/src/tools/read-file.ts
• packages/core/src/tools/read-many-files.ts
• packages/core/src/tools/repoMap.ts
• packages/core/src/tools/runTests.ts
• packages/core/src/tools/think.ts
• packages/core/src/tools/todoWrite.ts
• packages/core/src/tools/tool-registry.ts
• packages/core/src/tools/tools.ts
• packages/core/src/types/delta.ts
• packages/core/src/utils/editCorrector.ts
• packages/core/src/utils/environmentContext.ts
• packages/core/src/utils/errorReporting.ts
• packages/core/src/utils/fileUtils.ts
• packages/core/src/utils/generateContentResponseUtilities.ts
• packages/core/src/utils/messageInspectors.ts
• packages/core/src/utils/nextSpeakerChecker.ts
• packages/core/src/utils/partUtils.ts
• packages/core/src/utils/summarizer.ts

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📝 Walkthrough

Walkthrough

This pull request introduces a centralized Delta type definitions module and migrates 40+ files to import types from it instead of directly from @google/genai. A new delta.ts barrel exports re-exported types from @google/genai plus two new provider-agnostic types (DeltaModelCapabilities and DeltaProviderType). A roadmap document outlines the staged decoupling plan.

Changes

Cohort / File(s)	Summary
Documentation docs/roadmap/05-delta-types.md	New roadmap document describing the staged plan to decouple from @google/genai via Delta-native types, provider adapters, and interface migrations for ContentGenerator.
Type Definitions packages/core/src/types/delta.ts	New barrel module re-exporting message, request/response, embedding, tool, schema, and enum types from @google/genai. Introduces new types: DeltaModelCapabilities interface and DeltaProviderType string union.
CLI Package - Main & Integration packages/cli/src/nonInteractiveCli.ts, packages/cli/src/zed-integration/zedIntegration.ts	Updated imports of Content, Part, FunctionCall, and PartListUnion from @google/genai to local delta.ts module.
CLI Package - UI Types & Hooks packages/cli/src/ui/commands/types.ts, packages/cli/src/ui/hooks/atCommandProcessor.ts, packages/cli/src/ui/hooks/shellCommandProcessor.ts, packages/cli/src/ui/hooks/slashCommandProcessor.ts, packages/cli/src/ui/hooks/useDeltaStream.ts	Updated type imports (Content, Part, PartListUnion, FinishReason) across multiple hook and type definition files to use delta.ts instead of @google/genai.
Core Package - Core Modules packages/core/src/core/client.ts, packages/core/src/core/coreToolScheduler.ts, packages/core/src/core/deltaRequest.ts, packages/core/src/core/logger.ts, packages/core/src/core/subagent.ts, packages/core/src/core/turn.ts	Migrated imports of core types (PartListUnion, Content, GenerateContentConfig, FunctionDeclaration, FunctionCall, Part, GenerateContentResponse, FinishReason) from @google/genai to delta.ts.
Core Package - deltaChat (Bidirectional) packages/core/src/core/deltaChat.ts	Moved SendMessageParameters and createUserContent from delta.ts to @google/genai; kept Part and Tool from delta.ts.
Telemetry & Test Utilities packages/core/src/telemetry/types.ts, packages/core/src/test-utils/tools.ts	Updated GenerateContentResponseUsageMetadata, Schema, and Type imports from @google/genai to delta.ts.
Tool Files packages/core/src/tools/checkpoint.ts, packages/core/src/tools/diffPreview.ts, packages/core/src/tools/fileSummary.ts, packages/core/src/tools/lint.ts, packages/core/src/tools/mcp-client.ts, packages/core/src/tools/mcp-tool.ts, packages/core/src/tools/memoryTool.ts, packages/core/src/tools/multiEdit.ts, packages/core/src/tools/read-file.ts, packages/core/src/tools/read-many-files.ts, packages/core/src/tools/repoMap.ts, packages/core/src/tools/runTests.ts, packages/core/src/tools/think.ts, packages/core/src/tools/todoWrite.ts, packages/core/src/tools/tool-registry.ts, packages/core/src/tools/tools.ts	Systematically updated FunctionDeclaration, PartListUnion, PartUnion, CallableTool, FunctionCall, and Part imports from @google/genai to delta.ts across all tool modules.
Utility Files packages/core/src/utils/editCorrector.ts, packages/core/src/utils/environmentContext.ts, packages/core/src/utils/errorReporting.ts, packages/core/src/utils/fileUtils.ts, packages/core/src/utils/generateContentResponseUtilities.ts, packages/core/src/utils/messageInspectors.ts, packages/core/src/utils/nextSpeakerChecker.ts, packages/core/src/utils/partUtils.ts, packages/core/src/utils/summarizer.ts	Migrated Content, Part, PartListUnion, PartUnion, GenerateContentResponse, GenerateContentConfig, and FunctionCall imports from @google/genai to delta.ts across utility modules.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~28 minutes

Poem

🐰 Through files both great and small we hop,
Importing types from one new stop—
Delta's barrel, shiny and bright,
Decouples from Google's genai height!
Forty files refactored with care,
A cleaner codebase now to share! 🌟

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch refactor/delta-types

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