From 7bda699d598c1c87ade4f39fb471cad2380d1059 Mon Sep 17 00:00:00 2001
From: Daren Eiri <dareneiri@gmail.com>
Date: Thu, 9 Apr 2026 16:01:23 -0700
Subject: [PATCH 1/7] initial push for adding new function:
 chat_azure_anthropic

---
 DESCRIPTION                                   |   3 +-
 NAMESPACE                                     |   1 +
 NEWS.md                                       |   4 +
 R/provider-azure-anthropic.R                  | 202 ++++++++++++++++++
 man/chat_anthropic.Rd                         |   1 +
 man/chat_aws_bedrock.Rd                       |   1 +
 man/chat_azure_anthropic.Rd                   | 119 +++++++++++
 man/chat_azure_openai.Rd                      |   1 +
 man/chat_cloudflare.Rd                        |   1 +
 man/chat_databricks.Rd                        |   1 +
 man/chat_deepseek.Rd                          |   1 +
 man/chat_github.Rd                            |   1 +
 man/chat_google_gemini.Rd                     |   1 +
 man/chat_groq.Rd                              |   1 +
 man/chat_huggingface.Rd                       |   1 +
 man/chat_mistral.Rd                           |   1 +
 man/chat_ollama.Rd                            |   1 +
 man/chat_openai.Rd                            |   1 +
 man/chat_openai_compatible.Rd                 |   1 +
 man/chat_openrouter.Rd                        |   1 +
 man/chat_perplexity.Rd                        |   1 +
 man/chat_portkey.Rd                           |   1 +
 .../test-provider-azure-anthropic-24.R        |  19 ++
 .../test-provider-azure-anthropic-47.R        |  17 ++
 .../_snaps/provider-azure-anthropic.md        |  23 ++
 .../testthat/test-provider-azure-anthropic.R  |  88 ++++++++
 26 files changed, 492 insertions(+), 1 deletion(-)
 create mode 100644 R/provider-azure-anthropic.R
 create mode 100644 man/chat_azure_anthropic.Rd
 create mode 100644 tests/testthat/_problems/test-provider-azure-anthropic-24.R
 create mode 100644 tests/testthat/_problems/test-provider-azure-anthropic-47.R
 create mode 100644 tests/testthat/_snaps/provider-azure-anthropic.md
 create mode 100644 tests/testthat/test-provider-azure-anthropic.R

diff --git a/DESCRIPTION b/DESCRIPTION
index 092a284b3..aa50961c6 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -92,11 +92,12 @@ Collate:
     'params.R'
     'provider-any.R'
     'provider-aws.R'
+    'provider-claude.R'
     'provider-openai-compatible.R'
     'provider-azure.R'
+    'provider-azure-anthropic.R'
     'provider-claude-files.R'
     'provider-claude-tools.R'
-    'provider-claude.R'
     'provider-google.R'
     'provider-cloudflare.R'
     'provider-databricks.R'
diff --git a/NAMESPACE b/NAMESPACE
index e748db401..61198380e 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -37,6 +37,7 @@ export(batch_chat_text)
 export(chat)
 export(chat_anthropic)
 export(chat_aws_bedrock)
+export(chat_azure_anthropic)
 export(chat_azure_openai)
 export(chat_claude)
 export(chat_cloudflare)
diff --git a/NEWS.md b/NEWS.md
index 40420b0d9..fab4904ac 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,9 @@
 # ellmer (development version)
 
+* New `chat_azure_anthropic()` enables chatting with Anthropic Claude models
+  hosted on Azure AI Foundry (`*.services.ai.azure.com/anthropic` endpoints),
+  with the same Azure authentication options as `chat_azure_openai()` (#585).
+
 * Fixed three bugs that caused errors when streaming web search results: Claude's `citations_delta` events were mishandled, `server_tool_use` input wasn't parsed from JSON during streaming, and OpenAI's `web_search_call` failed for non-search action types like `open_page` (#941).
 * `chat_aws_bedrock()` gains a `cache` parameter for prompt caching. The default, `"auto"`, enables caching for models known to support it (Anthropic Claude and Amazon Nova) and disables it otherwise (#954).
 * Built-in tools (e.g., `openai_tool_web_search()`, `claude_tool_web_search()`) now include `description` and `annotations` properties, making their metadata consistent with user-defined tools created by `tool()` (#942).
diff --git a/R/provider-azure-anthropic.R b/R/provider-azure-anthropic.R
new file mode 100644
index 000000000..67ba1c0b6
--- /dev/null
+++ b/R/provider-azure-anthropic.R
@@ -0,0 +1,202 @@
+#' @include provider-azure.R
+#' @include provider-claude.R
+NULL
+
+# https://learn.microsoft.com/en-us/azure/ai-services/models/get-started
+
+#' Chat with an Anthropic Claude model hosted on Azure AI Foundry
+#'
+#' @description
+#' [Azure AI Foundry](https://azure.microsoft.com/en-us/products/ai-foundry)
+#' hosts Anthropic Claude models accessible via the
+#' `*.services.ai.azure.com/anthropic` endpoint, using the Anthropic Messages
+#' API format.
+#'
+#' Unlike [chat_azure_openai()], which targets `*.openai.azure.com` endpoints
+#' and uses the OpenAI chat completions format, this function targets Azure AI
+#' Foundry's Anthropic-compatible endpoint.
+#'
+#' ## Authentication
+#'
+#' `chat_azure_anthropic()` supports API keys via the `AZURE_ANTHROPIC_API_KEY`
+#' environment variable and the `credentials` parameter. It also supports:
+#'
+#' - Azure service principals (when the `AZURE_TENANT_ID`, `AZURE_CLIENT_ID`,
+#'   and `AZURE_CLIENT_SECRET` environment variables are set).
+#' - Interactive Entra ID authentication, like the Azure CLI.
+#' - Viewer-based credentials on Posit Connect. Requires the \pkg{connectcreds}
+#'   package.
+#'
+#' @param endpoint Azure AI Foundry endpoint URL with protocol and hostname,
+#'   i.e. `https://{your-project}.services.ai.azure.com/anthropic`. Defaults
+#'   to the value of the `AZURE_ANTHROPIC_ENDPOINT` environment variable.
+#' @param model The model name to use (e.g., `"claude-opus-4-5"`).
+#'   Defaults to `"claude-sonnet-4-5-20250929"`.
+#' @param api_version The API version to use.
+#' @param credentials `r api_key_param("AZURE_ANTHROPIC_API_KEY")`
+#' @inheritParams chat_anthropic
+#' @inherit chat_openai return
+#' @family chatbots
+#' @export
+#' @examples
+#' \dontrun{
+#' chat <- chat_azure_anthropic(
+#'   endpoint = "https://your-project.services.ai.azure.com/anthropic",
+#'   model = "claude-opus-4-5"
+#' )
+#' chat$chat("Tell me three jokes about statisticians")
+#' }
+chat_azure_anthropic <- function(
+  endpoint = azure_anthropic_endpoint(),
+  model = NULL,
+  params = NULL,
+  api_version = NULL,
+  system_prompt = NULL,
+  credentials = NULL,
+  cache = c("5m", "1h", "none"),
+  beta_headers = character(),
+  api_args = list(),
+  api_headers = character(),
+  echo = NULL
+) {
+  check_string(endpoint)
+  params <- params %||% params()
+  api_version <- set_default(api_version, "2024-10-22")
+  model <- set_default(model, "claude-sonnet-4-5-20250929")
+  cache <- arg_match(cache)
+  echo <- check_echo(echo)
+
+  credentials <- as_credentials(
+    "chat_azure_anthropic",
+    default_azure_anthropic_credentials(),
+    credentials = credentials
+  )
+
+  provider <- ProviderAzureAnthropic(
+    name = "Azure/Anthropic",
+    base_url = paste0(endpoint, "/v1"),
+    model = model,
+    params = params,
+    api_version = api_version,
+    credentials = credentials,
+    extra_args = api_args,
+    extra_headers = api_headers,
+    beta_headers = beta_headers,
+    cache = cache
+  )
+
+  Chat$new(provider = provider, system_prompt = system_prompt, echo = echo)
+}
+
+ProviderAzureAnthropic <- new_class(
+  "ProviderAzureAnthropic",
+  parent = ProviderAnthropic,
+  properties = list(
+    api_version = prop_string()
+  )
+)
+
+azure_anthropic_endpoint <- function() {
+  key_get("AZURE_ANTHROPIC_ENDPOINT")
+}
+
+# https://learn.microsoft.com/en-us/azure/ai-services/openai/reference
+method(base_request, ProviderAzureAnthropic) <- function(provider) {
+  req <- request(provider@base_url)
+  req <- ellmer_req_robustify(req, is_transient = function(resp) {
+    resp_status(resp) %in% c(429, 503, 529)
+  })
+  req <- ellmer_req_user_agent(req)
+  # Azure AI Foundry uses api-key header (not x-api-key like standard Anthropic)
+  req <- ellmer_req_credentials(req, provider@credentials(), "api-key")
+  req <- req_url_query(req, `api-version` = provider@api_version)
+
+  if (length(provider@beta_headers) > 0) {
+    req <- req_headers(req, `anthropic-beta` = provider@beta_headers)
+  }
+
+  req <- req_error(req, body = function(resp) {
+    if (resp_content_type(resp) == "application/json") {
+      json <- resp_body_json(resp)
+      paste0(json$error$message, " [", json$error$type, "]")
+    }
+  })
+
+  req
+}
+
+default_azure_anthropic_credentials <- function() {
+  azure_scope <- "https://cognitiveservices.azure.com/.default"
+
+  # Detect viewer-based credentials from Posit Connect.
+  if (has_connect_viewer_token(scope = azure_scope)) {
+    return(function() {
+      token <- connectcreds::connect_viewer_token(scope = azure_scope)
+      list(Authorization = paste("Bearer", token$access_token))
+    })
+  }
+
+  # Detect Azure service principals.
+  tenant_id <- Sys.getenv("AZURE_TENANT_ID")
+  client_id <- Sys.getenv("AZURE_CLIENT_ID")
+  client_secret <- Sys.getenv("AZURE_CLIENT_SECRET")
+  if (nchar(tenant_id) && nchar(client_id) && nchar(client_secret)) {
+    client <- oauth_client(
+      client_id,
+      token_url = paste0(
+        "https://login.microsoftonline.com/",
+        tenant_id,
+        "/oauth2/v2.0/token"
+      ),
+      secret = client_secret,
+      auth = "body",
+      name = "ellmer-azure-anthropic-sp"
+    )
+    return(function() {
+      token <- oauth_token_cached(
+        client,
+        oauth_flow_client_credentials,
+        flow_params = list(scope = azure_scope),
+        reauth = is_testing()
+      )
+      list(Authorization = paste("Bearer", token$access_token))
+    })
+  }
+
+  # If we have an API key, include it in the credentials.
+  api_key <- Sys.getenv("AZURE_ANTHROPIC_API_KEY")
+  if (nchar(api_key)) {
+    return(\() api_key)
+  }
+
+  # Masquerade as the Azure CLI.
+  client_id <- "04b07795-8ddb-461a-bbee-02f9e1bf7b46"
+  if (is_interactive() && !is_hosted_session()) {
+    client <- oauth_client(
+      client_id,
+      token_url = "https://login.microsoftonline.com/common/oauth2/v2.0/token",
+      secret = "",
+      auth = "body",
+      name = paste0("ellmer-", client_id)
+    )
+    return(function() {
+      token <- oauth_token_cached(
+        client,
+        oauth_flow_auth_code,
+        flow_params = list(
+          auth_url = "https://login.microsoftonline.com/common/oauth2/v2.0/authorize",
+          scope = paste(azure_scope, "offline_access"),
+          redirect_uri = "http://localhost:8400",
+          auth_params = list(prompt = "select_account")
+        )
+      )
+      list(Authorization = paste("Bearer", token$access_token))
+    })
+  }
+
+  if (is_testing()) {
+    testthat::skip("no Azure credentials available")
+  }
+
+  cli::cli_abort("No Azure credentials are available.")
+}
diff --git a/man/chat_anthropic.Rd b/man/chat_anthropic.Rd
index 66cc5738a..89aa4be58 100644
--- a/man/chat_anthropic.Rd
+++ b/man/chat_anthropic.Rd
@@ -148,6 +148,7 @@ chat$chat("Tell me three jokes about statisticians")
 \seealso{
 Other chatbots: 
 \code{\link{chat_aws_bedrock}()},
+\code{\link{chat_azure_anthropic}()},
 \code{\link{chat_azure_openai}()},
 \code{\link{chat_cloudflare}()},
 \code{\link{chat_databricks}()},
diff --git a/man/chat_aws_bedrock.Rd b/man/chat_aws_bedrock.Rd
index 29e1840a5..ffa7a0702 100644
--- a/man/chat_aws_bedrock.Rd
+++ b/man/chat_aws_bedrock.Rd
@@ -118,6 +118,7 @@ chat$chat("Tell me three jokes about statisticians")
 \seealso{
 Other chatbots: 
 \code{\link{chat_anthropic}()},
+\code{\link{chat_azure_anthropic}()},
 \code{\link{chat_azure_openai}()},
 \code{\link{chat_cloudflare}()},
 \code{\link{chat_databricks}()},
diff --git a/man/chat_azure_anthropic.Rd b/man/chat_azure_anthropic.Rd
new file mode 100644
index 000000000..92eded9b6
--- /dev/null
+++ b/man/chat_azure_anthropic.Rd
@@ -0,0 +1,119 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/provider-azure-anthropic.R
+\name{chat_azure_anthropic}
+\alias{chat_azure_anthropic}
+\title{Chat with an Anthropic Claude model hosted on Azure AI Foundry}
+\usage{
+chat_azure_anthropic(
+  endpoint = azure_anthropic_endpoint(),
+  model = NULL,
+  params = NULL,
+  api_version = NULL,
+  system_prompt = NULL,
+  credentials = NULL,
+  cache = c("5m", "1h", "none"),
+  beta_headers = character(),
+  api_args = list(),
+  api_headers = character(),
+  echo = NULL
+)
+}
+\arguments{
+\item{endpoint}{Azure AI Foundry endpoint URL with protocol and hostname,
+i.e. \verb{https://\{your-project\}.services.ai.azure.com/anthropic}. Defaults
+to the value of the \code{AZURE_ANTHROPIC_ENDPOINT} environment variable.}
+
+\item{model}{The model name to use (e.g., \code{"claude-opus-4-5"}).
+Defaults to \code{"claude-sonnet-4-5-20250929"}.}
+
+\item{params}{Common model parameters, usually created by \code{\link[=params]{params()}}.}
+
+\item{api_version}{The API version to use.}
+
+\item{system_prompt}{A system prompt to set the behavior of the assistant.}
+
+\item{credentials}{Override the default credentials. You generally should not need this argument; instead set the \code{AZURE_ANTHROPIC_API_KEY} environment variable. The best place to set this is in \code{.Renviron},
+which you can easily edit by calling \code{usethis::edit_r_environ()}.
+
+If you do need additional control, this argument takes a zero-argument function that returns either a string (the API key), or a named list (added as additional headers to every request).}
+
+\item{cache}{How long to cache inputs? Defaults to "5m" (five minutes).
+Set to "none" to disable caching or "1h" to cache for one hour.
+
+See details below.}
+
+\item{beta_headers}{Optionally, a character vector of beta headers to opt-in
+claude features that are still in beta.}
+
+\item{api_args}{Named list of arbitrary extra arguments appended to the body
+of every chat API call. Combined with the body object generated by ellmer
+with \code{\link[=modifyList]{modifyList()}}.}
+
+\item{api_headers}{Named character vector of arbitrary extra headers appended
+to every chat API call.}
+
+\item{echo}{One of the following options:
+\itemize{
+\item \code{none}: don't emit any output (default when running in a function).
+\item \code{output}: echo text and tool-calling output as it streams in (default
+when running at the console).
+\item \code{all}: echo all input and output.
+}
+
+Note this only affects the \code{chat()} method.}
+}
+\value{
+A \link{Chat} object.
+}
+\description{
+\href{https://azure.microsoft.com/en-us/products/ai-foundry}{Azure AI Foundry}
+hosts Anthropic Claude models accessible via the
+\verb{*.services.ai.azure.com/anthropic} endpoint, using the Anthropic Messages
+API format.
+
+Unlike \code{\link[=chat_azure_openai]{chat_azure_openai()}}, which targets \verb{*.openai.azure.com} endpoints
+and uses the OpenAI chat completions format, this function targets Azure AI
+Foundry's Anthropic-compatible endpoint.
+\subsection{Authentication}{
+
+\code{chat_azure_anthropic()} supports API keys via the \code{AZURE_ANTHROPIC_API_KEY}
+environment variable and the \code{credentials} parameter. It also supports:
+\itemize{
+\item Azure service principals (when the \code{AZURE_TENANT_ID}, \code{AZURE_CLIENT_ID},
+and \code{AZURE_CLIENT_SECRET} environment variables are set).
+\item Interactive Entra ID authentication, like the Azure CLI.
+\item Viewer-based credentials on Posit Connect. Requires the \pkg{connectcreds}
+package.
+}
+}
+}
+\examples{
+\dontrun{
+chat <- chat_azure_anthropic(
+  endpoint = "https://your-project.services.ai.azure.com/anthropic",
+  model = "claude-opus-4-5"
+)
+chat$chat("Tell me three jokes about statisticians")
+}
+}
+\seealso{
+Other chatbots: 
+\code{\link{chat_anthropic}()},
+\code{\link{chat_aws_bedrock}()},
+\code{\link{chat_azure_openai}()},
+\code{\link{chat_cloudflare}()},
+\code{\link{chat_databricks}()},
+\code{\link{chat_deepseek}()},
+\code{\link{chat_github}()},
+\code{\link{chat_google_gemini}()},
+\code{\link{chat_groq}()},
+\code{\link{chat_huggingface}()},
+\code{\link{chat_mistral}()},
+\code{\link{chat_ollama}()},
+\code{\link{chat_openai}()},
+\code{\link{chat_openai_compatible}()},
+\code{\link{chat_openrouter}()},
+\code{\link{chat_perplexity}()},
+\code{\link{chat_portkey}()}
+}
+\concept{chatbots}
diff --git a/man/chat_azure_openai.Rd b/man/chat_azure_openai.Rd
index 64fb46afb..48c8ed903 100644
--- a/man/chat_azure_openai.Rd
+++ b/man/chat_azure_openai.Rd
@@ -89,6 +89,7 @@ chat$chat("Tell me three jokes about statisticians")
 Other chatbots: 
 \code{\link{chat_anthropic}()},
 \code{\link{chat_aws_bedrock}()},
+\code{\link{chat_azure_anthropic}()},
 \code{\link{chat_cloudflare}()},
 \code{\link{chat_databricks}()},
 \code{\link{chat_deepseek}()},
diff --git a/man/chat_cloudflare.Rd b/man/chat_cloudflare.Rd
index 139416eb9..0f80ca818 100644
--- a/man/chat_cloudflare.Rd
+++ b/man/chat_cloudflare.Rd
@@ -78,6 +78,7 @@ chat$chat("Tell me three jokes about statisticians")
 Other chatbots: 
 \code{\link{chat_anthropic}()},
 \code{\link{chat_aws_bedrock}()},
+\code{\link{chat_azure_anthropic}()},
 \code{\link{chat_azure_openai}()},
 \code{\link{chat_databricks}()},
 \code{\link{chat_deepseek}()},
diff --git a/man/chat_databricks.Rd b/man/chat_databricks.Rd
index 9bb467f2a..84996ffc4 100644
--- a/man/chat_databricks.Rd
+++ b/man/chat_databricks.Rd
@@ -89,6 +89,7 @@ chat$chat("Tell me three jokes about statisticians")
 Other chatbots: 
 \code{\link{chat_anthropic}()},
 \code{\link{chat_aws_bedrock}()},
+\code{\link{chat_azure_anthropic}()},
 \code{\link{chat_azure_openai}()},
 \code{\link{chat_cloudflare}()},
 \code{\link{chat_deepseek}()},
diff --git a/man/chat_deepseek.Rd b/man/chat_deepseek.Rd
index a2965b7a3..77a7a5d72 100644
--- a/man/chat_deepseek.Rd
+++ b/man/chat_deepseek.Rd
@@ -74,6 +74,7 @@ chat$chat("Tell me three jokes about statisticians")
 Other chatbots: 
 \code{\link{chat_anthropic}()},
 \code{\link{chat_aws_bedrock}()},
+\code{\link{chat_azure_anthropic}()},
 \code{\link{chat_azure_openai}()},
 \code{\link{chat_cloudflare}()},
 \code{\link{chat_databricks}()},
diff --git a/man/chat_github.Rd b/man/chat_github.Rd
index 255bcf251..9f6645003 100644
--- a/man/chat_github.Rd
+++ b/man/chat_github.Rd
@@ -83,6 +83,7 @@ chat$chat("Tell me three jokes about statisticians")
 Other chatbots: 
 \code{\link{chat_anthropic}()},
 \code{\link{chat_aws_bedrock}()},
+\code{\link{chat_azure_anthropic}()},
 \code{\link{chat_azure_openai}()},
 \code{\link{chat_cloudflare}()},
 \code{\link{chat_databricks}()},
diff --git a/man/chat_google_gemini.Rd b/man/chat_google_gemini.Rd
index efbfcb8f2..6ecd38c04 100644
--- a/man/chat_google_gemini.Rd
+++ b/man/chat_google_gemini.Rd
@@ -113,6 +113,7 @@ chat$chat("Tell me three jokes about statisticians")
 Other chatbots: 
 \code{\link{chat_anthropic}()},
 \code{\link{chat_aws_bedrock}()},
+\code{\link{chat_azure_anthropic}()},
 \code{\link{chat_azure_openai}()},
 \code{\link{chat_cloudflare}()},
 \code{\link{chat_databricks}()},
diff --git a/man/chat_groq.Rd b/man/chat_groq.Rd
index 72a6ba94e..d5c83d88f 100644
--- a/man/chat_groq.Rd
+++ b/man/chat_groq.Rd
@@ -69,6 +69,7 @@ chat$chat("Tell me three jokes about statisticians")
 Other chatbots: 
 \code{\link{chat_anthropic}()},
 \code{\link{chat_aws_bedrock}()},
+\code{\link{chat_azure_anthropic}()},
 \code{\link{chat_azure_openai}()},
 \code{\link{chat_cloudflare}()},
 \code{\link{chat_databricks}()},
diff --git a/man/chat_huggingface.Rd b/man/chat_huggingface.Rd
index 565cb0072..0314bbe21 100644
--- a/man/chat_huggingface.Rd
+++ b/man/chat_huggingface.Rd
@@ -77,6 +77,7 @@ chat$chat("Tell me three jokes about statisticians")
 Other chatbots: 
 \code{\link{chat_anthropic}()},
 \code{\link{chat_aws_bedrock}()},
+\code{\link{chat_azure_anthropic}()},
 \code{\link{chat_azure_openai}()},
 \code{\link{chat_cloudflare}()},
 \code{\link{chat_databricks}()},
diff --git a/man/chat_mistral.Rd b/man/chat_mistral.Rd
index f4238746c..e78306860 100644
--- a/man/chat_mistral.Rd
+++ b/man/chat_mistral.Rd
@@ -74,6 +74,7 @@ chat$chat("Tell me three jokes about statisticians")
 Other chatbots: 
 \code{\link{chat_anthropic}()},
 \code{\link{chat_aws_bedrock}()},
+\code{\link{chat_azure_anthropic}()},
 \code{\link{chat_azure_openai}()},
 \code{\link{chat_cloudflare}()},
 \code{\link{chat_databricks}()},
diff --git a/man/chat_ollama.Rd b/man/chat_ollama.Rd
index 622da3362..cb472ccaf 100644
--- a/man/chat_ollama.Rd
+++ b/man/chat_ollama.Rd
@@ -90,6 +90,7 @@ chat$chat("Tell me three jokes about statisticians")
 Other chatbots: 
 \code{\link{chat_anthropic}()},
 \code{\link{chat_aws_bedrock}()},
+\code{\link{chat_azure_anthropic}()},
 \code{\link{chat_azure_openai}()},
 \code{\link{chat_cloudflare}()},
 \code{\link{chat_databricks}()},
diff --git a/man/chat_openai.Rd b/man/chat_openai.Rd
index 7f660b04e..60a6de656 100644
--- a/man/chat_openai.Rd
+++ b/man/chat_openai.Rd
@@ -97,6 +97,7 @@ chat$chat("Tell me three funny jokes about statisticians")
 Other chatbots: 
 \code{\link{chat_anthropic}()},
 \code{\link{chat_aws_bedrock}()},
+\code{\link{chat_azure_anthropic}()},
 \code{\link{chat_azure_openai}()},
 \code{\link{chat_cloudflare}()},
 \code{\link{chat_databricks}()},
diff --git a/man/chat_openai_compatible.Rd b/man/chat_openai_compatible.Rd
index 794d29b43..94637b1fd 100644
--- a/man/chat_openai_compatible.Rd
+++ b/man/chat_openai_compatible.Rd
@@ -81,6 +81,7 @@ chat$chat("What is the difference between a tibble and a data frame?")
 Other chatbots: 
 \code{\link{chat_anthropic}()},
 \code{\link{chat_aws_bedrock}()},
+\code{\link{chat_azure_anthropic}()},
 \code{\link{chat_azure_openai}()},
 \code{\link{chat_cloudflare}()},
 \code{\link{chat_databricks}()},
diff --git a/man/chat_openrouter.Rd b/man/chat_openrouter.Rd
index f5ceac9e2..ef3f5ac06 100644
--- a/man/chat_openrouter.Rd
+++ b/man/chat_openrouter.Rd
@@ -66,6 +66,7 @@ chat$chat("Tell me three jokes about statisticians")
 Other chatbots: 
 \code{\link{chat_anthropic}()},
 \code{\link{chat_aws_bedrock}()},
+\code{\link{chat_azure_anthropic}()},
 \code{\link{chat_azure_openai}()},
 \code{\link{chat_cloudflare}()},
 \code{\link{chat_databricks}()},
diff --git a/man/chat_perplexity.Rd b/man/chat_perplexity.Rd
index dc2e93641..8c4b627e6 100644
--- a/man/chat_perplexity.Rd
+++ b/man/chat_perplexity.Rd
@@ -75,6 +75,7 @@ chat$chat("Tell me three jokes about statisticians")
 Other chatbots: 
 \code{\link{chat_anthropic}()},
 \code{\link{chat_aws_bedrock}()},
+\code{\link{chat_azure_anthropic}()},
 \code{\link{chat_azure_openai}()},
 \code{\link{chat_cloudflare}()},
 \code{\link{chat_databricks}()},
diff --git a/man/chat_portkey.Rd b/man/chat_portkey.Rd
index 20d11a401..cb5c500fa 100644
--- a/man/chat_portkey.Rd
+++ b/man/chat_portkey.Rd
@@ -81,6 +81,7 @@ chat$chat("Tell me three jokes about statisticians")
 Other chatbots: 
 \code{\link{chat_anthropic}()},
 \code{\link{chat_aws_bedrock}()},
+\code{\link{chat_azure_anthropic}()},
 \code{\link{chat_azure_openai}()},
 \code{\link{chat_cloudflare}()},
 \code{\link{chat_databricks}()},
diff --git a/tests/testthat/_problems/test-provider-azure-anthropic-24.R b/tests/testthat/_problems/test-provider-azure-anthropic-24.R
new file mode 100644
index 000000000..e971b5a6b
--- /dev/null
+++ b/tests/testthat/_problems/test-provider-azure-anthropic-24.R
@@ -0,0 +1,19 @@
+# Extracted from test-provider-azure-anthropic.R:24
+
+# setup ------------------------------------------------------------------------
+library(testthat)
+test_env <- simulate_test_env(package = "ellmer", path = "..")
+attach(test_env, warn.conflicts = FALSE)
+
+# test -------------------------------------------------------------------------
+turn <- UserTurn(
+    contents = list(ContentText("What is 1 + 1?"))
+  )
+endpoint <- "https://example.services.ai.azure.com/anthropic"
+p <- ProviderAzureAnthropic(
+    name = "Azure/Anthropic",
+    base_url = paste0(endpoint, "/v1"),
+    model = "claude-opus-4-5",
+    api_version = "2024-10-22",
+    credentials = \() "key"
+  )
diff --git a/tests/testthat/_problems/test-provider-azure-anthropic-47.R b/tests/testthat/_problems/test-provider-azure-anthropic-47.R
new file mode 100644
index 000000000..743f496b9
--- /dev/null
+++ b/tests/testthat/_problems/test-provider-azure-anthropic-47.R
@@ -0,0 +1,17 @@
+# Extracted from test-provider-azure-anthropic.R:47
+
+# setup ------------------------------------------------------------------------
+library(testthat)
+test_env <- simulate_test_env(package = "ellmer", path = "..")
+attach(test_env, warn.conflicts = FALSE)
+
+# test -------------------------------------------------------------------------
+endpoint <- "https://example.services.ai.azure.com/anthropic"
+p <- ProviderAzureAnthropic(
+    name = "Azure/Anthropic",
+    base_url = paste0(endpoint, "/v1"),
+    model = "claude-opus-4-5",
+    api_version = "2024-10-22",
+    credentials = \() "key",
+    beta_headers = c("feature-a", "feature-b")
+  )
diff --git a/tests/testthat/_snaps/provider-azure-anthropic.md b/tests/testthat/_snaps/provider-azure-anthropic.md
new file mode 100644
index 000000000..ed65b9c1f
--- /dev/null
+++ b/tests/testthat/_snaps/provider-azure-anthropic.md
@@ -0,0 +1,23 @@
+# defaults are reported
+
+    Code
+      . <- chat_azure_anthropic("https://example.services.ai.azure.com/anthropic")
+    Message
+      Using api_version = "2024-10-22".
+      Using model = "claude-sonnet-4-5-20250929".
+
+# service principal authentication requests look correct
+
+    Code
+      str(request_summary(req))
+    Output
+      List of 3
+       $ url    : chr "https://login.microsoftonline.com/aaaa0a0a-bb1b-cc2c-dd3d-eeeeee4e4e4e/oauth2/v2.0/token"
+       $ headers:List of 1
+        ..$ Accept: chr "application/json"
+       $ body   :List of 4
+        ..$ grant_type   : 'AsIs' chr "client_credentials"
+        ..$ scope        : 'AsIs' chr "https%3A%2F%2Fcognitiveservices.azure.com%2F.default"
+        ..$ client_id    : 'AsIs' chr "id"
+        ..$ client_secret: 'AsIs' chr "secret"
+
diff --git a/tests/testthat/test-provider-azure-anthropic.R b/tests/testthat/test-provider-azure-anthropic.R
new file mode 100644
index 000000000..62a40d70c
--- /dev/null
+++ b/tests/testthat/test-provider-azure-anthropic.R
@@ -0,0 +1,88 @@
+# Defaults ----------------------------------------------------------------
+
+test_that("defaults are reported", {
+  withr::local_envvar(AZURE_ANTHROPIC_API_KEY = "key")
+  expect_snapshot(
+    . <- chat_azure_anthropic("https://example.services.ai.azure.com/anthropic")
+  )
+})
+
+# Authentication ----------------------------------------------------------
+
+test_that("Azure Anthropic request headers are generated correctly", {
+  turn <- UserTurn(
+    contents = list(ContentText("What is 1 + 1?"))
+  )
+  endpoint <- "https://example.services.ai.azure.com/anthropic"
+
+  p <- ProviderAzureAnthropic(
+    name = "Azure/Anthropic",
+    base_url = paste0(endpoint, "/v1"),
+    model = "claude-opus-4-5",
+    params = list(),
+    extra_args = list(),
+    extra_headers = character(),
+    credentials = \() "key",
+    beta_headers = character(),
+    cache = "none",
+    api_version = "2024-10-22"
+  )
+  req <- chat_request(p, FALSE, list(turn))
+  headers <- req_get_headers(req, "reveal")
+
+  # Uses api-key header, not x-api-key like standard Anthropic
+  expect_equal(headers$`api-key`, "key")
+  expect_null(headers$`x-api-key`)
+  # No anthropic-version header; Azure uses api-version query param instead
+  expect_null(headers$`anthropic-version`)
+  # api-version appears as a query parameter
+  expect_match(req$url, "api-version=2024-10-22")
+})
+
+test_that("beta headers are forwarded correctly", {
+  endpoint <- "https://example.services.ai.azure.com/anthropic"
+
+  p <- ProviderAzureAnthropic(
+    name = "Azure/Anthropic",
+    base_url = paste0(endpoint, "/v1"),
+    model = "claude-opus-4-5",
+    params = list(),
+    extra_args = list(),
+    extra_headers = character(),
+    credentials = \() "key",
+    beta_headers = c("feature-a", "feature-b"),
+    cache = "none",
+    api_version = "2024-10-22"
+  )
+  req <- base_request(p)
+  headers <- req_get_headers(req)
+  expect_equal(headers$`anthropic-beta`, "feature-a,feature-b")
+})
+
+test_that("service principal authentication requests look correct", {
+  withr::local_envvar(
+    AZURE_TENANT_ID = "aaaa0a0a-bb1b-cc2c-dd3d-eeeeee4e4e4e",
+    AZURE_CLIENT_ID = "id",
+    AZURE_CLIENT_SECRET = "secret"
+  )
+  local_mocked_responses(function(req) {
+    expect_snapshot(str(request_summary(req)))
+    response_json(body = list(access_token = "token"))
+  })
+  source <- default_azure_anthropic_credentials()
+  expect_equal(source(), list(Authorization = "Bearer token"))
+})
+
+test_that("tokens can be requested from a Connect server", {
+  skip_if_not_installed("connectcreds")
+
+  connectcreds::local_mocked_connect_responses(token = "token")
+  credentials <- default_azure_anthropic_credentials()
+  expect_equal(credentials(), list(Authorization = "Bearer token"))
+})
+
+test_that("API key is read from AZURE_ANTHROPIC_API_KEY", {
+  withr::local_envvar(AZURE_ANTHROPIC_API_KEY = "my-key")
+  credentials <- default_azure_anthropic_credentials()
+  expect_equal(credentials(), "my-key")
+})

From cb276fd2b3f5c67b024a3cedbec210571115305d Mon Sep 17 00:00:00 2001
From: Daren Eiri <dareneiri@gmail.com>
Date: Thu, 9 Apr 2026 21:23:34 -0700
Subject: [PATCH 2/7] resolve authentication issues

---
 R/provider-azure-anthropic.R                  | 34 +------------------
 man/chat_azure_anthropic.Rd                   |  3 --
 .../test-provider-azure-anthropic-24.R        | 16 ++++-----
 .../test-provider-azure-anthropic-47.R        | 14 ++++----
 .../_snaps/provider-azure-anthropic.md        |  1 -
 .../testthat/test-provider-azure-anthropic.R  | 23 ++++++-------
 6 files changed, 26 insertions(+), 65 deletions(-)

diff --git a/R/provider-azure-anthropic.R b/R/provider-azure-anthropic.R
index 67ba1c0b6..855691b40 100644
--- a/R/provider-azure-anthropic.R
+++ b/R/provider-azure-anthropic.R
@@ -32,7 +32,6 @@ NULL
 #'   to the value of the `AZURE_ANTHROPIC_ENDPOINT` environment variable.
 #' @param model The model name to use (e.g., `"claude-opus-4-5"`).
 #'   Defaults to `"claude-sonnet-4-5-20250929"`.
-#' @param api_version The API version to use.
 #' @param credentials `r api_key_param("AZURE_ANTHROPIC_API_KEY")`
 #' @inheritParams chat_anthropic
 #' @inherit chat_openai return
@@ -50,7 +49,6 @@ chat_azure_anthropic <- function(
   endpoint = azure_anthropic_endpoint(),
   model = NULL,
   params = NULL,
-  api_version = NULL,
   system_prompt = NULL,
   credentials = NULL,
   cache = c("5m", "1h", "none"),
@@ -61,7 +59,6 @@ chat_azure_anthropic <- function(
 ) {
   check_string(endpoint)
   params <- params %||% params()
-  api_version <- set_default(api_version, "2024-10-22")
   model <- set_default(model, "claude-sonnet-4-5-20250929")
   cache <- arg_match(cache)
   echo <- check_echo(echo)
@@ -77,7 +74,6 @@ chat_azure_anthropic <- function(
     base_url = paste0(endpoint, "/v1"),
     model = model,
     params = params,
-    api_version = api_version,
     credentials = credentials,
     extra_args = api_args,
     extra_headers = api_headers,
@@ -90,41 +86,13 @@ chat_azure_anthropic <- function(
 
 ProviderAzureAnthropic <- new_class(
   "ProviderAzureAnthropic",
-  parent = ProviderAnthropic,
-  properties = list(
-    api_version = prop_string()
-  )
+  parent = ProviderAnthropic
 )
 
 azure_anthropic_endpoint <- function() {
   key_get("AZURE_ANTHROPIC_ENDPOINT")
 }
 
-# https://learn.microsoft.com/en-us/azure/ai-services/openai/reference
-method(base_request, ProviderAzureAnthropic) <- function(provider) {
-  req <- request(provider@base_url)
-  req <- ellmer_req_robustify(req, is_transient = function(resp) {
-    resp_status(resp) %in% c(429, 503, 529)
-  })
-  req <- ellmer_req_user_agent(req)
-  # Azure AI Foundry uses api-key header (not x-api-key like standard Anthropic)
-  req <- ellmer_req_credentials(req, provider@credentials(), "api-key")
-  req <- req_url_query(req, `api-version` = provider@api_version)
-
-  if (length(provider@beta_headers) > 0) {
-    req <- req_headers(req, `anthropic-beta` = provider@beta_headers)
-  }
-
-  req <- req_error(req, body = function(resp) {
-    if (resp_content_type(resp) == "application/json") {
-      json <- resp_body_json(resp)
-      paste0(json$error$message, " [", json$error$type, "]")
-    }
-  })
-
-  req
-}
-
 default_azure_anthropic_credentials <- function() {
   azure_scope <- "https://cognitiveservices.azure.com/.default"
 
diff --git a/man/chat_azure_anthropic.Rd b/man/chat_azure_anthropic.Rd
index 92eded9b6..093c25909 100644
--- a/man/chat_azure_anthropic.Rd
+++ b/man/chat_azure_anthropic.Rd
@@ -8,7 +8,6 @@ chat_azure_anthropic(
   endpoint = azure_anthropic_endpoint(),
   model = NULL,
   params = NULL,
-  api_version = NULL,
   system_prompt = NULL,
   credentials = NULL,
   cache = c("5m", "1h", "none"),
@@ -28,8 +27,6 @@ Defaults to \code{"claude-sonnet-4-5-20250929"}.}
 
 \item{params}{Common model parameters, usually created by \code{\link[=params]{params()}}.}
 
-\item{api_version}{The API version to use.}
-
 \item{system_prompt}{A system prompt to set the behavior of the assistant.}
 
 \item{credentials}{Override the default credentials. You generally should not need this argument; instead set the \code{AZURE_ANTHROPIC_API_KEY} environment variable. The best place to set this is in \code{.Renviron},
diff --git a/tests/testthat/_problems/test-provider-azure-anthropic-24.R b/tests/testthat/_problems/test-provider-azure-anthropic-24.R
index e971b5a6b..4d948fca2 100644
--- a/tests/testthat/_problems/test-provider-azure-anthropic-24.R
+++ b/tests/testthat/_problems/test-provider-azure-anthropic-24.R
@@ -7,13 +7,13 @@ attach(test_env, warn.conflicts = FALSE)
 
 # test -------------------------------------------------------------------------
 turn <- UserTurn(
-    contents = list(ContentText("What is 1 + 1?"))
-  )
+  contents = list(ContentText("What is 1 + 1?"))
+)
 endpoint <- "https://example.services.ai.azure.com/anthropic"
 p <- ProviderAzureAnthropic(
-    name = "Azure/Anthropic",
-    base_url = paste0(endpoint, "/v1"),
-    model = "claude-opus-4-5",
-    api_version = "2024-10-22",
-    credentials = \() "key"
-  )
+  name = "Azure/Anthropic",
+  base_url = paste0(endpoint, "/v1"),
+  model = "claude-opus-4-5",
+  api_version = "2024-10-22",
+  credentials = \() "key"
+)
diff --git a/tests/testthat/_problems/test-provider-azure-anthropic-47.R b/tests/testthat/_problems/test-provider-azure-anthropic-47.R
index 743f496b9..4ecac106c 100644
--- a/tests/testthat/_problems/test-provider-azure-anthropic-47.R
+++ b/tests/testthat/_problems/test-provider-azure-anthropic-47.R
@@ -8,10 +8,10 @@ attach(test_env, warn.conflicts = FALSE)
 # test -------------------------------------------------------------------------
 endpoint <- "https://example.services.ai.azure.com/anthropic"
 p <- ProviderAzureAnthropic(
-    name = "Azure/Anthropic",
-    base_url = paste0(endpoint, "/v1"),
-    model = "claude-opus-4-5",
-    api_version = "2024-10-22",
-    credentials = \() "key",
-    beta_headers = c("feature-a", "feature-b")
-  )
+  name = "Azure/Anthropic",
+  base_url = paste0(endpoint, "/v1"),
+  model = "claude-opus-4-5",
+  api_version = "2024-10-22",
+  credentials = \() "key",
+  beta_headers = c("feature-a", "feature-b")
+)
diff --git a/tests/testthat/_snaps/provider-azure-anthropic.md b/tests/testthat/_snaps/provider-azure-anthropic.md
index ed65b9c1f..1a5eaaec8 100644
--- a/tests/testthat/_snaps/provider-azure-anthropic.md
+++ b/tests/testthat/_snaps/provider-azure-anthropic.md
@@ -3,7 +3,6 @@
     Code
       . <- chat_azure_anthropic("https://example.services.ai.azure.com/anthropic")
     Message
-      Using api_version = "2024-10-22".
       Using model = "claude-sonnet-4-5-20250929".
 
 # service principal authentication requests look correct
diff --git a/tests/testthat/test-provider-azure-anthropic.R b/tests/testthat/test-provider-azure-anthropic.R
index 62a40d70c..6865a6e35 100644
--- a/tests/testthat/test-provider-azure-anthropic.R
+++ b/tests/testthat/test-provider-azure-anthropic.R
@@ -18,25 +18,23 @@ test_that("Azure Anthropic request headers are generated correctly", {
   p <- ProviderAzureAnthropic(
     name = "Azure/Anthropic",
     base_url = paste0(endpoint, "/v1"),
-    model = "claude-opus-4-5",
+    model = "claude-sonnet-4-6",
     params = list(),
     extra_args = list(),
     extra_headers = character(),
     credentials = \() "key",
     beta_headers = character(),
-    cache = "none",
-    api_version = "2024-10-22"
+    cache = "none"
   )
   req <- chat_request(p, FALSE, list(turn))
   headers <- req_get_headers(req, "reveal")
 
-  # Uses api-key header, not x-api-key like standard Anthropic
-  expect_equal(headers$`api-key`, "key")
-  expect_null(headers$`x-api-key`)
-  # No anthropic-version header; Azure uses api-version query param instead
-  expect_null(headers$`anthropic-version`)
-  # api-version appears as a query parameter
-  expect_match(req$url, "api-version=2024-10-22")
+  # Uses x-api-key and anthropic-version, same as standard Anthropic API
+  expect_equal(headers$`x-api-key`, "key")
+  expect_equal(headers$`anthropic-version`, "2023-06-01")
+  expect_null(headers$`api-key`)
+  # No api-version query parameter
+  expect_no_match(req$url, "api-version")
 })
 
 test_that("beta headers are forwarded correctly", {
@@ -45,14 +43,13 @@ test_that("beta headers are forwarded correctly", {
   p <- ProviderAzureAnthropic(
     name = "Azure/Anthropic",
     base_url = paste0(endpoint, "/v1"),
-    model = "claude-opus-4-5",
+    model = "claude-sonnet-4-6",
     params = list(),
     extra_args = list(),
     extra_headers = character(),
     credentials = \() "key",
     beta_headers = c("feature-a", "feature-b"),
-    cache = "none",
-    api_version = "2024-10-22"
+    cache = "none"
   )
   req <- base_request(p)
   headers <- req_get_headers(req)

From e6af65eb6373cbb75441287318fcd9f9006253e6 Mon Sep 17 00:00:00 2001
From: Daren Eiri <dareneiri@gmail.com>
Date: Thu, 9 Apr 2026 22:00:44 -0700
Subject: [PATCH 3/7] remove default value for model to ensure it's user
 defined

---
 R/provider-azure-anthropic.R                      | 7 +++----
 man/chat_azure_anthropic.Rd                       | 5 ++---
 tests/testthat/_snaps/provider-azure-anthropic.md | 7 -------
 tests/testthat/test-provider-azure-anthropic.R    | 7 ++++---
 4 files changed, 9 insertions(+), 17 deletions(-)

diff --git a/R/provider-azure-anthropic.R b/R/provider-azure-anthropic.R
index 855691b40..52649b491 100644
--- a/R/provider-azure-anthropic.R
+++ b/R/provider-azure-anthropic.R
@@ -30,8 +30,7 @@ NULL
 #' @param endpoint Azure AI Foundry endpoint URL with protocol and hostname,
 #'   i.e. `https://{your-project}.services.ai.azure.com/anthropic`. Defaults
 #'   to the value of the `AZURE_ANTHROPIC_ENDPOINT` environment variable.
-#' @param model The model name to use (e.g., `"claude-opus-4-5"`).
-#'   Defaults to `"claude-sonnet-4-5-20250929"`.
+#' @param model The **deployment name** for the model you want to use.
 #' @param credentials `r api_key_param("AZURE_ANTHROPIC_API_KEY")`
 #' @inheritParams chat_anthropic
 #' @inherit chat_openai return
@@ -47,7 +46,7 @@ NULL
 #' }
 chat_azure_anthropic <- function(
   endpoint = azure_anthropic_endpoint(),
-  model = NULL,
+  model,
   params = NULL,
   system_prompt = NULL,
   credentials = NULL,
@@ -58,8 +57,8 @@ chat_azure_anthropic <- function(
   echo = NULL
 ) {
   check_string(endpoint)
+  check_string(model)
   params <- params %||% params()
-  model <- set_default(model, "claude-sonnet-4-5-20250929")
   cache <- arg_match(cache)
   echo <- check_echo(echo)
 
diff --git a/man/chat_azure_anthropic.Rd b/man/chat_azure_anthropic.Rd
index 093c25909..918f5dfba 100644
--- a/man/chat_azure_anthropic.Rd
+++ b/man/chat_azure_anthropic.Rd
@@ -6,7 +6,7 @@
 \usage{
 chat_azure_anthropic(
   endpoint = azure_anthropic_endpoint(),
-  model = NULL,
+  model,
   params = NULL,
   system_prompt = NULL,
   credentials = NULL,
@@ -22,8 +22,7 @@ chat_azure_anthropic(
 i.e. \verb{https://\{your-project\}.services.ai.azure.com/anthropic}. Defaults
 to the value of the \code{AZURE_ANTHROPIC_ENDPOINT} environment variable.}
 
-\item{model}{The model name to use (e.g., \code{"claude-opus-4-5"}).
-Defaults to \code{"claude-sonnet-4-5-20250929"}.}
+\item{model}{The \strong{deployment name} for the model you want to use.}
 
 \item{params}{Common model parameters, usually created by \code{\link[=params]{params()}}.}
 
diff --git a/tests/testthat/_snaps/provider-azure-anthropic.md b/tests/testthat/_snaps/provider-azure-anthropic.md
index 1a5eaaec8..352ed1277 100644
--- a/tests/testthat/_snaps/provider-azure-anthropic.md
+++ b/tests/testthat/_snaps/provider-azure-anthropic.md
@@ -1,10 +1,3 @@
-# defaults are reported
-
-    Code
-      . <- chat_azure_anthropic("https://example.services.ai.azure.com/anthropic")
-    Message
-      Using model = "claude-sonnet-4-5-20250929".
-
 # service principal authentication requests look correct
 
     Code
diff --git a/tests/testthat/test-provider-azure-anthropic.R b/tests/testthat/test-provider-azure-anthropic.R
index 6865a6e35..8b1071019 100644
--- a/tests/testthat/test-provider-azure-anthropic.R
+++ b/tests/testthat/test-provider-azure-anthropic.R
@@ -1,9 +1,10 @@
 # Defaults ----------------------------------------------------------------
 
-test_that("defaults are reported", {
+test_that("model is required", {
   withr::local_envvar(AZURE_ANTHROPIC_API_KEY = "key")
-  expect_snapshot(
-    . <- chat_azure_anthropic("https://example.services.ai.azure.com/anthropic")
+  expect_error(
+    chat_azure_anthropic("https://example.services.ai.azure.com/anthropic"),
+    "model"
   )
 })
 

From f90e909e57f87e744b19e838cba1eb10e9b0fa69 Mon Sep 17 00:00:00 2001
From: Daren Eiri <dareneiri@gmail.com>
Date: Thu, 9 Apr 2026 23:07:22 -0700
Subject: [PATCH 4/7] remove trailing slash at end of url

---
 R/provider-azure-anthropic.R                   |  4 ++--
 man/chat_azure_anthropic.Rd                    |  2 +-
 tests/testthat/test-provider-azure-anthropic.R | 10 ++++++++++
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/R/provider-azure-anthropic.R b/R/provider-azure-anthropic.R
index 52649b491..91e38d48a 100644
--- a/R/provider-azure-anthropic.R
+++ b/R/provider-azure-anthropic.R
@@ -40,7 +40,7 @@ NULL
 #' \dontrun{
 #' chat <- chat_azure_anthropic(
 #'   endpoint = "https://your-project.services.ai.azure.com/anthropic",
-#'   model = "claude-opus-4-5"
+#'   model = "your-deployment-name"
 #' )
 #' chat$chat("Tell me three jokes about statisticians")
 #' }
@@ -70,7 +70,7 @@ chat_azure_anthropic <- function(
 
   provider <- ProviderAzureAnthropic(
     name = "Azure/Anthropic",
-    base_url = paste0(endpoint, "/v1"),
+    base_url = paste0(gsub("/$", "", endpoint), "/v1"),
     model = model,
     params = params,
     credentials = credentials,
diff --git a/man/chat_azure_anthropic.Rd b/man/chat_azure_anthropic.Rd
index 918f5dfba..0dc955356 100644
--- a/man/chat_azure_anthropic.Rd
+++ b/man/chat_azure_anthropic.Rd
@@ -87,7 +87,7 @@ package.
 \dontrun{
 chat <- chat_azure_anthropic(
   endpoint = "https://your-project.services.ai.azure.com/anthropic",
-  model = "claude-opus-4-5"
+  model = "your-deployment-name"
 )
 chat$chat("Tell me three jokes about statisticians")
 }
diff --git a/tests/testthat/test-provider-azure-anthropic.R b/tests/testthat/test-provider-azure-anthropic.R
index 8b1071019..92c61b8f8 100644
--- a/tests/testthat/test-provider-azure-anthropic.R
+++ b/tests/testthat/test-provider-azure-anthropic.R
@@ -8,6 +8,16 @@ test_that("model is required", {
   )
 })
 
+test_that("trailing slash in endpoint is handled correctly", {
+  withr::local_envvar(AZURE_ANTHROPIC_API_KEY = "key")
+  chat <- chat_azure_anthropic(
+    endpoint = "https://example.services.ai.azure.com/anthropic/",
+    model = "claude-sonnet-4-6"
+  )
+  expect_no_match(chat$get_provider()@base_url, "//v1")
+  expect_match(chat$get_provider()@base_url, "/v1$")
+})
+
 # Authentication ----------------------------------------------------------
 
 test_that("Azure Anthropic request headers are generated correctly", {

From 5e163b4081c2634642bd3f5e744fa1c972673249 Mon Sep 17 00:00:00 2001
From: Daren Eiri <dareneiri@gmail.com>
Date: Thu, 9 Apr 2026 23:14:07 -0700
Subject: [PATCH 5/7] update link for docs

---
 R/provider-azure-anthropic.R | 3 +--
 man/chat_azure_anthropic.Rd  | 3 ++-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/R/provider-azure-anthropic.R b/R/provider-azure-anthropic.R
index 91e38d48a..71afcd99c 100644
--- a/R/provider-azure-anthropic.R
+++ b/R/provider-azure-anthropic.R
@@ -2,11 +2,10 @@
 #' @include provider-claude.R
 NULL
 
-# https://learn.microsoft.com/en-us/azure/ai-services/models/get-started
+# https://learn.microsoft.com/en-us/azure/foundry/foundry-models/concepts/endpoints
 
 #' Chat with an Anthropic Claude model hosted on Azure AI Foundry
 #'
-#' @description
 #' [Azure AI Foundry](https://azure.microsoft.com/en-us/products/ai-foundry)
 #' hosts Anthropic Claude models accessible via the
 #' `*.services.ai.azure.com/anthropic` endpoint, using the Anthropic Messages
diff --git a/man/chat_azure_anthropic.Rd b/man/chat_azure_anthropic.Rd
index 0dc955356..8b5e2c87d 100644
--- a/man/chat_azure_anthropic.Rd
+++ b/man/chat_azure_anthropic.Rd
@@ -66,7 +66,8 @@ A \link{Chat} object.
 hosts Anthropic Claude models accessible via the
 \verb{*.services.ai.azure.com/anthropic} endpoint, using the Anthropic Messages
 API format.
-
+}
+\details{
 Unlike \code{\link[=chat_azure_openai]{chat_azure_openai()}}, which targets \verb{*.openai.azure.com} endpoints
 and uses the OpenAI chat completions format, this function targets Azure AI
 Foundry's Anthropic-compatible endpoint.

From 0c07e4e9bb7f7b37d37fa0914e65ac6e1d578b38 Mon Sep 17 00:00:00 2001
From: Daren Eiri <dareneiri@gmail.com>
Date: Thu, 9 Apr 2026 23:22:54 -0700
Subject: [PATCH 6/7] clean up uncesssary files

---
 .../test-provider-azure-anthropic-24.R        | 19 -------------------
 .../test-provider-azure-anthropic-47.R        | 17 -----------------
 .../_snaps/provider-azure-anthropic.md        | 15 ---------------
 .../testthat/test-provider-azure-anthropic.R  | 10 +++++++++-
 4 files changed, 9 insertions(+), 52 deletions(-)
 delete mode 100644 tests/testthat/_problems/test-provider-azure-anthropic-24.R
 delete mode 100644 tests/testthat/_problems/test-provider-azure-anthropic-47.R
 delete mode 100644 tests/testthat/_snaps/provider-azure-anthropic.md

diff --git a/tests/testthat/_problems/test-provider-azure-anthropic-24.R b/tests/testthat/_problems/test-provider-azure-anthropic-24.R
deleted file mode 100644
index 4d948fca2..000000000
--- a/tests/testthat/_problems/test-provider-azure-anthropic-24.R
+++ /dev/null
@@ -1,19 +0,0 @@
-# Extracted from test-provider-azure-anthropic.R:24
-
-# setup ------------------------------------------------------------------------
-library(testthat)
-test_env <- simulate_test_env(package = "ellmer", path = "..")
-attach(test_env, warn.conflicts = FALSE)
-
-# test -------------------------------------------------------------------------
-turn <- UserTurn(
-  contents = list(ContentText("What is 1 + 1?"))
-)
-endpoint <- "https://example.services.ai.azure.com/anthropic"
-p <- ProviderAzureAnthropic(
-  name = "Azure/Anthropic",
-  base_url = paste0(endpoint, "/v1"),
-  model = "claude-opus-4-5",
-  api_version = "2024-10-22",
-  credentials = \() "key"
-)
diff --git a/tests/testthat/_problems/test-provider-azure-anthropic-47.R b/tests/testthat/_problems/test-provider-azure-anthropic-47.R
deleted file mode 100644
index 4ecac106c..000000000
--- a/tests/testthat/_problems/test-provider-azure-anthropic-47.R
+++ /dev/null
@@ -1,17 +0,0 @@
-# Extracted from test-provider-azure-anthropic.R:47
-
-# setup ------------------------------------------------------------------------
-library(testthat)
-test_env <- simulate_test_env(package = "ellmer", path = "..")
-attach(test_env, warn.conflicts = FALSE)
-
-# test -------------------------------------------------------------------------
-endpoint <- "https://example.services.ai.azure.com/anthropic"
-p <- ProviderAzureAnthropic(
-  name = "Azure/Anthropic",
-  base_url = paste0(endpoint, "/v1"),
-  model = "claude-opus-4-5",
-  api_version = "2024-10-22",
-  credentials = \() "key",
-  beta_headers = c("feature-a", "feature-b")
-)
diff --git a/tests/testthat/_snaps/provider-azure-anthropic.md b/tests/testthat/_snaps/provider-azure-anthropic.md
deleted file mode 100644
index 352ed1277..000000000
--- a/tests/testthat/_snaps/provider-azure-anthropic.md
+++ /dev/null
@@ -1,15 +0,0 @@
-# service principal authentication requests look correct
-
-    Code
-      str(request_summary(req))
-    Output
-      List of 3
-       $ url    : chr "https://login.microsoftonline.com/aaaa0a0a-bb1b-cc2c-dd3d-eeeeee4e4e4e/oauth2/v2.0/token"
-       $ headers:List of 1
-        ..$ Accept: chr "application/json"
-       $ body   :List of 4
-        ..$ grant_type   : 'AsIs' chr "client_credentials"
-        ..$ scope        : 'AsIs' chr "https%3A%2F%2Fcognitiveservices.azure.com%2F.default"
-        ..$ client_id    : 'AsIs' chr "id"
-        ..$ client_secret: 'AsIs' chr "secret"
-
diff --git a/tests/testthat/test-provider-azure-anthropic.R b/tests/testthat/test-provider-azure-anthropic.R
index 92c61b8f8..215b450d1 100644
--- a/tests/testthat/test-provider-azure-anthropic.R
+++ b/tests/testthat/test-provider-azure-anthropic.R
@@ -74,7 +74,15 @@ test_that("service principal authentication requests look correct", {
     AZURE_CLIENT_SECRET = "secret"
   )
   local_mocked_responses(function(req) {
-    expect_snapshot(str(request_summary(req)))
+    summary <- request_summary(req)
+    expect_match(
+      summary$url,
+      "login.microsoftonline.com/aaaa0a0a-bb1b-cc2c-dd3d-eeeeee4e4e4e"
+    )
+    expect_match(summary$body$grant_type, "client_credentials")
+    expect_match(summary$body$scope, "cognitiveservices.azure.com")
+    expect_match(summary$body$client_id, "id")
+    expect_match(summary$body$client_secret, "secret")
     response_json(body = list(access_token = "token"))
   })
   source <- default_azure_anthropic_credentials()

From d05272d2922826a300f2b89c7800dcfc7177d9ef Mon Sep 17 00:00:00 2001
From: Daren Eiri <dareneiri@gmail.com>
Date: Fri, 10 Apr 2026 08:40:16 -0700
Subject: [PATCH 7/7] updated formatting in NEWS.md, removed mention of #585
 since that concerns Mistral access through Foundry, which this new
 functionality does not directly address

---
 NEWS.md | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/NEWS.md b/NEWS.md
index fab4904ac..400066372 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,9 +1,6 @@
 # ellmer (development version)
 
-* New `chat_azure_anthropic()` enables chatting with Anthropic Claude models
-  hosted on Azure AI Foundry (`*.services.ai.azure.com/anthropic` endpoints),
-  with the same Azure authentication options as `chat_azure_openai()` (#585).
-
+* New `chat_azure_anthropic()` enables chatting with Anthropic Claude models hosted on Azure AI Foundry (`*.services.ai.azure.com/anthropic` endpoints), with the same Azure authentication options as `chat_azure_openai()`.
 * Fixed three bugs that caused errors when streaming web search results: Claude's `citations_delta` events were mishandled, `server_tool_use` input wasn't parsed from JSON during streaming, and OpenAI's `web_search_call` failed for non-search action types like `open_page` (#941).
 * `chat_aws_bedrock()` gains a `cache` parameter for prompt caching. The default, `"auto"`, enables caching for models known to support it (Anthropic Claude and Amazon Nova) and disables it otherwise (#954).
 * Built-in tools (e.g., `openai_tool_web_search()`, `claude_tool_web_search()`) now include `description` and `annotations` properties, making their metadata consistent with user-defined tools created by `tool()` (#942).