> ## Documentation Index
> Fetch the complete documentation index at: https://docs.evolvingmachines.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Models

> How a model is named on -m, and why one API key covers every provider.

`-m` names the model an arm runs, as the harness knows it. One `EVOLVE_API_KEY` covers every provider: you never configure a provider key for a job, and every model call that goes through the platform's gateway is metered against the trial's spend cap. The cap is airtight only on a task that declares `no-network`; under `allowlist` or `public` an agent can reach a provider directly with a key of its own, and that traffic is neither metered nor capped.

```bash theme={null}
evolve run \
  -d terminal-bench-4@4.0 \
  -a claude \
  -m fable \
  -l 5 \
  --watch
evolve run \
  -d terminal-bench-4@4.0 \
  -a codex \
  -m gpt-6-astra \
  -m gpt-5.6-terra \
  -l 5 \
  --watch
```

`-m` repeats. Each model is one arm, so the second command runs every task twice, once per model. Every arm must name a model; there is no default.

With a provider key of your own enabled, model calls bill that provider account instead of credits; the cap still applies, and a zero credit balance still refuses a job create, resume or retry.

## The rosters

Each harness has its own roster of model names. These are the names the SDK ships at this release. The platform publishes the live list for each harness in its capability document, which the SDK reads with `meta()`.

<Tabs>
  <Tab title="claude">
    `fable`, `opus`, `sonnet`, `haiku`, `opus[1m]`, `sonnet[1m]`, `glm-5.3`, `glm-5.3-flash`, `openrouter/deepseek/deepseek-v4.1-flash`, `fireworks/deepseek-v4.1-flash`
  </Tab>

  <Tab title="codex">
    `gpt-6-astra`, `gpt-5.6-sol`, `gpt-5.6-terra`, `gpt-5.6-luna`, `gpt-5.5`, `gpt-5.3-codex`
  </Tab>

  <Tab title="gemini">
    `gemini-3.5-flash`, `gemini-3.5-flash-lite`, `gemini-3.1-pro-preview`
  </Tab>

  <Tab title="qwen">
    `qwen3.7-max`, `qwen3.7-plus`, `qwen3.6-flash`
  </Tab>

  <Tab title="kimi">
    `kimi-k3`, `kimi-k2.7-code`, `kimi-k3-raptor`, `kimi-k2p7-code-raptor`
  </Tab>

  <Tab title="opencode">
    `openrouter/anthropic/claude-fable-5.1`, `openrouter/anthropic/claude-opus-5`, `openrouter/anthropic/claude-sonnet-5`, `openrouter/anthropic/claude-haiku-4.5`, `openrouter/openai/gpt-6-astra`, `openrouter/openai/gpt-5.6-sol`, `openrouter/openai/gpt-5.6-terra`, `openrouter/openai/gpt-5.6-luna`, `openrouter/google/gemini-3.6-flash`, `openrouter/qwen/qwen3.7-max`, `openrouter/moonshotai/kimi-k3`, `openrouter/z-ai/glm-5.3`, `openrouter/z-ai/glm-5.3-flash`, `openrouter/deepseek/deepseek-v4.1-flash`, `fireworks/deepseek-v4.1-flash`
  </Tab>

  <Tab title="droid">
    `claude-fable-5.1`, `claude-opus-5`, `claude-sonnet-5`, `claude-haiku-4-5`, `gpt-6-astra`, `gpt-5.6-sol`, `gpt-5.6-terra`, `gpt-5.6-luna`, `gemini-3.6-flash`, `qwen3.7-max`, `kimi-k3`, `glm-5.3`, `glm-5.3-flash`, `openrouter/deepseek/deepseek-v4.1-flash`, `fireworks/deepseek-v4.1-flash`
  </Tab>
</Tabs>

## Reasoning effort

`--effort <value>` sets the reasoning effort for every arm. The values each harness accepts are in the [capability document](/sdk-reference/meta), under its `effort_support`: `gemini` accepts no effort value, `qwen` switches thinking on or off rather than taking a level, and the other five harnesses take a level. An effort a harness cannot honor is refused with `invalid_input` when the job is created, never silently skipped.

An omitted effort resolves to the harness's own default and is stamped as if declared: every trial echoes it on `agent_info.reasoning_effort`, and the job's `stats.evals` keys carry it as the segment before the dataset, `agent__model__effort__dataset`. Effort is part of an arm's identity: the same agent and model at two efforts are two arms.

## The analyzer's and the checker's model

The analyzer and the checker run on the `claude` roster. Their default model is `openrouter/deepseek/deepseek-v4.1-flash`; `-m` on `evolve analyze` and `evolve check`, and `--analyze-model` on `evolve run`, pick another.

<Card title="Agents" icon="bot" href="/core-concepts/agents">
  The seven harnesses, and how to bring your own.
</Card>