Model discovery

Runtime discovery is the canonical answer to “what can this configured installation offer?”

llmshim models
curl http://localhost:3000/v1/models

Both commands filter the built-in registry to providers with configured API keys. The proxy returns id, provider, and unprefixed name; the CLI prints the ID and display label.

Registered catalog

The current registry contains 27 entries, newest first within each provider. This page mirrors src/models.rs; use runtime discovery rather than parsing this table in applications.

OpenAI

Anthropic

Google Gemini

xAI

Spec metadata

Each registry entry can also carry spec metadata beyond its identity, so a consumer can read a model's facts from one place instead of maintaining its own parallel table:

Support is tri-state: Supported, Unsupported, or Unknown. Unknown is honest, not a bug — llmshim never guesses a spec to fill a cell. As of the 2026-07-16 snapshot, context window, output ceiling, and capabilities are populated from official provider docs (platform.claude.com, developers.openai.com, ai.google.dev, docs.x.ai), and reasoning is cross-checked against the provider clamp logic. What's deliberately left Unknown/None:

• parallel_tool_calls for most models (providers rarely document it per model);
• xAI max_output_tokens (not published) and per-model streaming.

A few documented exceptions are recorded honestly too — e.g. gpt-5.5-pro has streaming: Unsupported and gpt-5.4-pro has structured_output: Unsupported. Note also that Gemini publishes an input limit rather than a combined total, so context_window_tokens is the input window with max_output_tokens separate.

reasoning is deliberately a single flag — "does this model accept a reasoning control at all." The detailed per-tier mapping is not duplicated here; it lives in the reasoning guide and the provider transforms.

Look up one model's full spec from the Rust crate:

#![allow(unused)]
fn main() {
if let Some(m) = llmshim::models::spec("openai/gpt-5.6-sol") {
    println!("{}: reasoning = {:?}", m.label, m.capabilities.reasoning);
}
}

spec() accepts a full id ("openai/gpt-5.6-sol") or a bare name ("gpt-5.6-sol") and returns None for unregistered models. These specs are a point-in-time snapshot pinned by the crate version, exactly like the list above.

Catalog is not an allowlist

The Router does not check explicit model names against this registry. If a provider is registered, provider/arbitrary-model-id is routed to that provider with arbitrary-model-id unchanged. A bare, unregistered model name works only when its prefix identifies a provider (gpt, o1, o3, o4, claude, gemini, or grok).

OpenRouter is intentionally not enumerated above — its catalog is large and dynamic. Any openrouter/<vendor>/<model> slug routes through (e.g. openrouter/anthropic/claude-sonnet-4.5, openrouter/meta-llama/llama-3.1-70b-instruct:nitro); the slug's internal slash and :variant suffix are preserved. Because its slugs collide with other providers' prefixes, OpenRouter has no bare-model inference — always address it explicitly as openrouter/….

Self-hosted vLLM / SGLang are likewise not enumerated. Set VLLM_BASE_URL or SGLANG_BASE_URL (with an optional *_API_KEY) and address the served model as vllm/<served-model> or sglang/<served-model> — e.g. sglang/Qwen/Qwen3.6-35B-A3B-FP8. Local vs remote is just the base-URL value.

Rust applications can also define one-level Router aliases with Router::alias. Those aliases are not part of the static registry and are not configured by the stock CLI or proxy. See Models and the Router.