AnthropicProvider — AnthropicProvider • EventStudy

A provider that issues POST {base_url}/v1/messages against the native Anthropic Messages API. The request carries the mandatory max_tokens field and the anthropic-version header; when a schema is supplied it adds a tool-use input_schema block (tools + tool_choice) to obtain structured output, and the response extractor prefers that tool call's structured input while falling back to the first text block — so the provider never crashes when the model replies with plain text instead of a tool call.

The API key is resolved at CALL time from ANTHROPIC_API_KEY (never at construction, never stored on the object) and attached with req_headers_redacted("x-api-key" = key), which redacts the key in every print/error path. Note req_auth_bearer_token does NOT redact an x-api-key header — the redacted-headers helper is mandatory here. A missing key, transport/timeout failure, non-2xx status, malformed body, or missing completion text each degrades to exactly one warning() plus an `es_provider_response` with text = NA_character_ — it never crashes the session and never returns a fabricated completion.

httr2 is required only for this provider and is guarded by requireNamespace() at the top of complete(), so the package installs and R CMD checks cleanly with httr2 absent.

Super class

ProviderBase -> AnthropicProvider

Public fields

max_tokens: Integer max completion tokens (Anthropic REQUIRES this).

Methods

`AnthropicProvider$new()`

Construct an AnthropicProvider. Stores non-secret config only; the API key is resolved at call time inside complete().

Usage

AnthropicProvider$new(
  model,
  base_url = "https://api.anthropic.com",
  max_tokens = 1024L,
  ...
)

Arguments

model: Character model identifier, e.g. "claude-opus-4-8".
base_url: Character base URL. Defaults to the Anthropic cloud endpoint.
max_tokens: Integer maximum number of tokens to generate. The Anthropic Messages API REQUIRES this field; defaults to 1024.
...: Ignored; accepted for forward-compatibility.

`AnthropicProvider$complete()`

Complete a prompt via POST {base_url}/v1/messages. Resolves the key at call time; on a missing key or any HTTP/parse failure returns one warning + NA. Structured output is OPTIONAL: when schema is supplied a tool-use input_schema block is added and the extractor prefers the tool call's input, falling back to the first text block.

Usage

AnthropicProvider$complete(prompt, schema = NULL, ...)

Arguments

prompt: Character prompt.
schema: Optional structured-output schema (list) or NULL.
...: Ignored; accepted for forward-compatibility.

Returns

An `es_provider_response` (see ProviderBase$complete).

`AnthropicProvider$clone()`

The objects of this class are cloneable with this method.

Usage

AnthropicProvider$clone(deep = FALSE)

Arguments

deep: Whether to make a deep clone.

Examples

if (FALSE) { # \dontrun{
# Reads ANTHROPIC_API_KEY from the environment at call time:
p <- AnthropicProvider$new(model = "claude-opus-4-8")
p$complete("Summarise these event-study diagnostics")

# Structured output via a tool-use input_schema:
schema <- list(type = "object",
               properties = list(advice = list(type = "string")))
p$complete("Recommend a test statistic", schema = schema)
} # }