One Go interface for every AI model.
📖 skyl-docs.vercel.app — the documentation site.
skyl is a small, dependency-light Go library that lets you talk to Claude, GPT, Gemini, and 400+ other models through a single, stable interface — then switch between them by changing one string.
client := skyl.New(anthropic.New(os.Getenv("ANTHROPIC_API_KEY")))
resp, err := client.Complete(ctx, &skyl.Request{
Model: "claude-opus-5",
Messages: []skyl.Message{skyl.UserText("Explain Go channels in two sentences.")},
})
fmt.Println(resp.Text())Swapping to GPT is a one-line change:
client := skyl.New(openai.New(os.Getenv("OPENAI_API_KEY")))Integrating an AI model into a Go service means writing the same 400 lines every time: request mapping, SSE parsing, retry with jitter, rate-limit backoff, token accounting, error classification. Then your provider ships a new model, or you want to A/B two vendors, and you write it again.
skyl does that once, properly, with tests.
| Provider-agnostic | One Request/Response shape across every vendor |
| Zero-day model support | Model IDs are pass-through strings — new models work the day they launch, with no skyl release |
| No lock-in | Every response carries Raw — the untouched provider JSON — so you are never blocked by our abstraction |
| Streaming that works | Unified SSE with proper context cancellation and no goroutine leaks |
| Honest errors | Typed, classified, errors.Is/errors.As-friendly |
| Small surface | The core module has zero external dependencies. No router, no logger, no framework |
go get github.com/BAGOMBEKA-JOB-DEV/skylRequires Go 1.22+, and the core module has zero external dependencies — so it imposes neither a dependency graph nor a recent toolchain on you. The adapter modules below need Go 1.24+, because the vendor SDKs they wrap do.
The Anthropic adapter is a separate module, because it uses the official Anthropic SDK and that brings a dozen transitive dependencies nobody else should pay for (ADR-0006):
go get github.com/BAGOMBEKA-JOB-DEV/skyl/provider/anthropicNative adapters — full fidelity, including provider-specific features (extended thinking, prompt caching, native tool calling):
| Adapter | Reaches |
|---|---|
provider/anthropic ⁽*⁾ |
Claude Opus 5, Fable 5, Sonnet 5, Haiku 4.5, all 4.x |
provider/openai |
GPT-5.6 (Sol/Terra/Luna), 5.5, 5.4 nano, o-series, gpt-oss |
provider/gemini |
Gemini 3.6 Flash, 3.5/3.1 Flash-Lite, 3 Pro |
⁽*⁾ separate module — install it explicitly, as shown above.
provider/openaicompat — one adapter, configured per host, reaches the
long tail of vendors that speak OpenAI's wire format:
xAI (Grok) · DeepSeek · Mistral · Groq · Together · Fireworks · OpenRouter · Perplexity · Cerebras · DeepInfra · Qwen/DashScope · Moonshot (Kimi) · Z.ai (GLM) · Nvidia NIM · Ollama · vLLM · LM Studio · llama.cpp
// Any OpenAI-compatible endpoint, including local ones.
client := skyl.New(openaicompat.New(
openaicompat.WithBaseURL("http://localhost:11434/v1"),
openaicompat.WithName("ollama"),
))Full details and the model-discovery story: docs/providers.md.
On GitHub Copilot: skyl deliberately does not ship a Copilot provider. Copilot has no public completions API — its REST endpoints are administrative only, and the Copilot SDK's BYOK mode forwards to other vendors' keys. A "Copilot provider" could only be a relabelled OpenAI call, which would be dishonest. See ADR-0005.
gateway/ is a separate module (its own go.mod) that exposes skyl over
HTTP using go-chi — one REST + SSE endpoint
that fans out to any configured provider. Use it when non-Go services need
model access, or when you want API keys held in exactly one place.
go run github.com/BAGOMBEKA-JOB-DEV/skyl/gateway/cmd/skyl-gatewayImporting the core library never pulls in chi. See docs/gateway.md and ADR-0003.
The documentation site is the friendliest way in: a Learn track to read in order, and a Reference track with one page per symbol. It is built from BAGOMBEKA-JOB-DEV/skyl_docs — a separate repository, so a docs change never touches the library's release history. Corrections to the site belong there; corrections to the files below belong here.
The documents in this repository stay authoritative for anything a decision depends on — the feature matrix, the threat model, the ADRs — because they are versioned with the code they describe.
| Document | What it covers |
|---|---|
| docs/idea.md | The problem, the goals, and the explicit non-goals |
| docs/getting-started.md | Install → first call → streaming → tools |
| docs/architecture.md | How the pieces fit and why |
| docs/providers.md | Provider coverage and model discovery |
| docs/gateway.md | The chi HTTP gateway |
| docs/project-plan.md | Milestones, scope, and status |
| docs/roadmap.md | What stands between this and production use |
| docs/feature-matrix.md | Which adapter supports what — including what each one silently ignores |
| docs/data-handling.md | What leaves your process, what is kept, what is logged |
| docs/threat-model.md | Trust boundaries, and what an authenticated gateway caller can do |
| docs/benchmarks.md | Measured allocation and throughput figures |
| docs/migrating.md | Coming from openai-go, anthropic-sdk-go, or langchaingo |
| docs/rules.md | Engineering rules every change must satisfy |
| docs/adr/ | Architecture decision records |
| CONTRIBUTING.md | How to propose and land a change |
| SECURITY.md | Reporting vulnerabilities; credential handling |
Pre-v1, and validated against live provider APIs. Everything here is implemented, unit-tested, contract-tested, exercised end to end over real sockets, and CI-green — and as of 2026-08-05 the integration suite has been run against the real OpenAI, Anthropic and Gemini endpoints and passes.
That last part is the one that took longest to be able to write. Every fake in this test suite was written from the same provider documentation as the adapter it tests, so a wrong field name is wrong identically in both and CI stays green regardless. Only a real call settles it, and one has now been made against each adapter: completions, streaming, tool calls, the multi-turn tool round trip, truncation, and error classification.
Pre-v1 still means what it says. The wire mapping is confirmed; the Go API
is not frozen and may change before v1.0.0 (docs/rules.md §1.2). Live
validation is a snapshot, not a subscription — providers change, and
docs/validating.md is how you re-run it yourself against
your own account and models.
There are three suites, and the third is the one CI cannot run for you:
go test ./... # mapping logic, in process
go test -tags=sandbox ./... # the full stack over real sockets — no keys needed
go test -tags=integration ./...# real providers — needs your keys, costs moneyCI runs the first two on every change. The third needs credentials, so it runs by hand — reproduce it with your own:
export ANTHROPIC_API_KEY=... OPENAI_API_KEY=... GEMINI_API_KEY=...
go test -tags=integration ./provider/
cd provider/anthropic && go test -tags=integration ./...Eight checks per provider, about nine upstream requests, pennies on a small model. docs/validating.md covers what each one proves and how to tell an adapter bug from a model being unhelpful.
To develop against skyl before you have any key, run the local sandbox — it speaks all four providers' wire protocols and costs nothing. See docs/sandbox.md.
go run ./cmd/skyl-sandboxThe API may also change ahead of the v1.0.0 tag. See docs/project-plan.md for what is done and what is next, and CHANGELOG.md for release history.
Apache License 2.0 — see LICENSE.