provider

The provider block declares a model provider the agent may use and how to connect to it. A manifest can contain any number of provider blocks, including several of the same kind. The value of agent.model.provider must be the label of one of them. The kind field determines the provider type and which fields the block accepts.

provider "anthropic" {
  kind   = "anthropic"
  models = ["claude-haiku-4-5"]

  config {
    api_key = secret(runtime("ANTHROPIC_API_KEY"))
  }
}

agent "assistant" {
  graph {
    type = "react"
  }

  model {
    provider = "anthropic"
    name     = "claude-haiku-4-5"
  }
}

Labels

The block label names the provider within the manifest. agent.model.provider refers to a provider by its label, and errors raised by a provider name its label. A label is chosen freely and may equal a kind name.

Shared structure

All provider blocks follow the same general shape. Which model entries models takes, which fields config accepts, and which inference parameters take effect differ per kind and are documented on each kind's reference page.

kind is required and selects the provider type. It is always build-time and cannot be wrapped in runtime().

models is an optional list of model entries. When present it acts as an allowlist: only the named models may be used in agent.model.name when this provider is selected. When absent, any model name is accepted. Each entry is either a plain model name string, or a config object with a name field and an optional params block for model-specific inference parameter overrides:

models = [
  "claude-haiku-4-5",
  {
    name = "claude-sonnet-4-6"
    params {
      max_tokens  = 8192
      temperature = 0.7
    }
  }
]

config is an optional block containing connection settings such as API keys and base URLs. Its fields, and what each falls back to when unset, are documented on each kind's page.

params is an optional block that sets inference parameter defaults for every model request made through this provider. These defaults are baked into every model instance at startup. Individual model entries in the models list can override specific fields by declaring their own params block. Model-level values take precedence over provider-level values.

params {
  max_tokens  = 4096
  temperature = 0.5
}

runtime() may wrap any config or params value to defer its resolution to deployment time. This lets you supply keys, URLs, and parameter values via environment variables without hardcoding them in the manifest.

secret() should additionally wrap any value that is sensitive. Marking a value as secret prevents it from appearing in build artifacts and in the output of agentc inspect. API keys should always be written as secret(runtime("ENV_VAR_NAME")).

Field paths

Each value set in a provider block has a config path under the block's label, and can be set at startup through the AGENT__ environment variable of the same path, as described in Deploy standalone.

A label containing characters other than letters, digits, and underscores is converted to snake case, so the label my-cloud has the path provider.my_cloud. In <model>, every character of the model name other than a letter or digit becomes _, so claude-opus-4-7 becomes claude_opus_4_7.

export AGENT__PROVIDER__ANTHROPIC__API_KEY=your_key_here
export AGENT__PROVIDER__ANTHROPIC__PARAMS__TEMPERATURE=0.2

Kinds