tools-only Providers
Set up OpenAI/Anthropic/Gemini/Ollama quickly and consult a single capability matrix. Requires Python 3.10+ and pip install alloy-ai.
Setup (quick)
Pick a provider, set its API key, and choose a model ID via ALLOY_MODEL. No code changes required.
OpenAI
export OPENAI_API_KEY=sk-...
export ALLOY_MODEL=gpt-5-mini
Anthropic (Claude)
export ANTHROPIC_API_KEY=...
export ALLOY_MODEL=claude-sonnet-4-20250514
# Anthropic requires max_tokens; Alloy uses 2048 if unset
Google Gemini
export GOOGLE_API_KEY=...
export ALLOY_MODEL=gemini-2.5-flash
Ollama (local)
export ALLOY_MODEL=ollama:<model>
Fake (offline/demo)
export ALLOY_BACKEND=fake
Capability Matrix (canonical)
| Provider | Text | Tools | Structured Outputs | Streaming Text | Streaming + Tools | Streaming + Structured | Notes |
|---|---|---|---|---|---|---|---|
| OpenAI | Yes | Yes | Yes | Yes | Yes | No | Uses Responses API; auto-finalize missing structured output on OpenAI when enabled. |
| Anthropic (Claude) | Yes | Yes | Yes | Yes | Yes | No | Requires max_tokens (Alloy uses 2048 if unset). |
| Google Gemini | Yes | Yes | Yes | Yes | Yes | No | Requires max_tool_turns configured; uses google-genai. |
| Ollama (local) | Yes | Yes | Yes | Yes | No | No | Two APIs: native /api/chat (JSON Schema via format, full Ollama options) and OpenAI‑compatible Chat Completions. Default is native; config auto‑routes ollama:*gpt-oss* to compat unless overridden via extra["ollama_api"]. |
| Fake (offline) | Yes | No | Yes (deterministic stub) | Yes | No | No | Offline backend for CI/examples; not for production. |
Note: “Streaming + Structured” is not yet supported. Streaming outputs currently stay text-only.
Ollama specifics
- API selection:
extra["ollama_api"] = "native" | "openai_chat". Default:native; config auto‑routesollama:*gpt-oss*toopenai_chatunless explicitly set. - Native API advantages: strict structured outputs with
format={JSON Schema}, Ollama‑specific options (e.g.,num_predict,num_ctx). - OpenAI‑compat advantages: drop‑in with OpenAI clients (e.g., gpt‑oss). Some Ollama knobs are not exposed here.
- Limitations: streaming is currently text-only; typed/object streaming is not yet supported. Ollama streaming remains text-only (no tools or structured outputs while streaming). Tool calling requires a tool‑capable model.
Migration notes
- Model naming may change; prefer lightweight defaults (e.g.,
gpt-5-mini,gemini-2.5-flash). - Tool result shapes and limits vary; Alloy normalizes common cases and raises clear errors where not supported.
- See Guide → Streaming for exact streaming semantics and preview status.