Add xAI (Grok) provider for @workglow/ai

[sroussey]

Adds a new @workglow/xai provider package that integrates xAI's Grok models with the Workglow AI framework. xAI exposes an OpenAI-compatible REST API, so this provider reuses the openai SDK pointed at https://api.x.ai/v1.

Key Changes

• New provider package (providers/xai/) with full AI task support:

  • Text generation (chat completions)
  • Tool use / function calling
  • Structured generation (JSON mode)
  • Vision input (for vision-capable models)
  • Image generation (grok-2-image and successors)
  • Text rewriting and summarization
  • Token counting (via tiktoken approximation)
  • Model search and info endpoints

• Capability inference (Xai_Capabilities.ts):

  • Pattern-matches Grok model IDs to infer capabilities
  • Distinguishes between chat models (grok-3, grok-4), vision models (grok-2-vision), and image models (grok-2-image)
  • Falls back to declared capabilities or baseline metadata operations

• Client abstraction (Xai_Client.ts):

  • Lazy-loads OpenAI SDK to avoid bundling cost on main thread
  • Validates base URL against allow-list (api.x.ai) with opt-out for enterprise gateways
  • Resolves API key from environment or credential store

• Streaming run-functions for all capabilities:

  • Unified text generation handler for both TextGenerationTask and AiChatTask
  • Tool calling with defense-in-depth filtering against hallucinated function names
  • Structured generation with partial JSON parsing and streaming
  • Image generation with base64 decoding

• Browser and Node.js variants:

  • Token counting uses js-tiktoken in browser, WASM tiktoken in Node.js
  • Separate build targets for ai.ts, ai.browser.ts, and ai-runtime.ts

• Integration tests (Xai_Generic.integration.test.ts):

  • Conformance tests against the AI provider contract
  • Skipped unless XAI_API_KEY environment variable is set

• Package exports and registration:

  • registerXai() for worker-backed mode
  • registerXaiInline() for inline mode
  • registerXaiWorker() for worker server registration
  • Integrated into @workglow/workglow meta-package

Implementation Details

• Follows existing provider patterns (Anthropic, OpenAI) with capability-set-based run-fn registration
• Uses OpenAI SDK's streaming interface for all streaming tasks
• Token counting approximates with cl100k_base encoding (xAI doesn't publish a public tokenizer)
• Image generation requests base64 output and converts to ImageValue via data URI
• Model search falls back to a hardcoded list if the API is unavailable

https://claude.ai/code/session_01Jx794dFEj3P7jT6pgytkaq

[github-actions]

Coverage Report

Status	Category	Percentage	Covered / Total
🔵	Lines	62.74%	25962 / 41379
🔵	Statements	62.58%	26865 / 42927
🔵	Functions	63.65%	4914 / 7720
🔵	Branches	51.32%	12709 / 24762

File Coverage

File	Stmts	Branches	Functions	Lines	Uncovered Lines
Changed Files
scripts/lib/test-credentials.ts	90.62%	78.57%	100%	89.28%	93-98

Generated in workflow #2684 for commit 0ddcb7e by the Vitest Coverage Report Action