Upstream sync: add :agent-model to custom-agents (PR #1309)

CHANGELOG.md

@@ -3,6 +3,14 @@ All notable changes to this project will be documented in this file. This change
 
 ## [Unreleased]
 
+### Added (post-v1.0.0-beta.4 sync)
+- **`:agent-model` on custom-agent configs** — Custom agent maps in
+  `:custom-agents` now accept an optional `:agent-model` string (e.g.
+  `"claude-haiku-4.5"`). When set, the runtime attempts to use that model
+  for the agent, falling back to the parent session model if unavailable.
+  Forwarded on the wire as `agentModel` on each entry in `customAgents`
+  for both `session.create` and `session.resume`. (upstream PR #1309)
+
 ### Notes (v1.0.0-beta.4 sync)
 Upstream `v1.0.0-beta.4` shipped no new Node.js SDK API surface relative to
 `v1.0.0-beta.3` — every SDK-visible change in the upstream diff

doc/reference/API.md

@@ -243,7 +243,7 @@ Create a client and session together, ensuring both are cleaned up on exit.
 | `:provider` | map | Provider config for BYOK (see [BYOK docs](../auth/byok.md)). Required key: `:base-url`. Optional: `:provider-type` (`:openai`/`:azure`/`:anthropic`), `:wire-api` (`:completions`/`:responses`), `:api-key`, `:bearer-token`, `:azure-options`, `:headers` (map of HTTP header name→value, sent with each provider request — upstream PR #1094), `:model-id` (string — the model identifier to send to the provider; overrides session `:model`), `:wire-model` (string — model name as sent on the provider wire when it differs from `:model-id`), `:max-input-tokens` (integer — input/prompt token cap; serialized as wire `maxPromptTokens`), `:max-output-tokens` (integer — output token cap). The four override fields were added in upstream PR #966 |
 | `:mcp-servers` | map | MCP server configs keyed by server ID (see [MCP docs](../mcp/overview.md)). Local (stdio) servers: `:mcp-command`, `:mcp-args`, `:mcp-tools`. Remote (HTTP/SSE) servers: `:mcp-server-type` (`:http`/`:sse`), `:mcp-url`, `:mcp-tools`. Spec aliases: `::mcp-stdio-server` = `::mcp-local-server`, `::mcp-http-server` = `::mcp-remote-server` |
 | `:commands` | vector | Command definitions (slash commands). See [Commands](#commands) |
-| `:custom-agents` | vector | Custom agent configs. Each agent map: `:agent-name` (required), `:agent-prompt` (required), `:agent-display-name`, `:agent-description`, `:agent-tools`, `:agent-infer?`, `:agent-skills` (vector of strings), `:mcp-servers` |
+| `:custom-agents` | vector | Custom agent configs. Each agent map: `:agent-name` (required), `:agent-prompt` (required), `:agent-display-name`, `:agent-description`, `:agent-tools`, `:agent-infer?`, `:agent-skills` (vector of strings), `:agent-model` (string, e.g. `"claude-haiku-4.5"`; when set the runtime tries this model for the agent, falling back to the parent session model — upstream PR #1309), `:mcp-servers` |
 | `:default-agent` | map | Built-in/default agent config. Use `{:excluded-tools [...]}` to hide tools from the default agent while leaving them available to custom agents |
 | `:on-permission-request` | fn | **Required.** Permission handler function. Use `copilot/approve-all` to approve everything. |
 | `:streaming?` | boolean | Enable streaming deltas |

src/github/copilot_sdk/specs.clj

@@ -274,11 +274,15 @@
 (s/def ::agent-prompt ::non-blank-string)
 (s/def ::agent-infer? boolean?)
 (s/def ::agent-skills (s/coll-of string?))
+;; Model identifier for the agent (e.g. "claude-haiku-4.5"). When set, the
+;; runtime will attempt to use this model for the agent, falling back to the
+;; parent session model if unavailable. Upstream PR #1309.
+(s/def ::agent-model ::non-blank-string)
 
 (s/def ::custom-agent
   (s/keys :req-un [::agent-name ::agent-prompt]
           :opt-un [::agent-display-name ::agent-description ::agent-tools
-                   ::mcp-servers ::agent-infer? ::agent-skills]))
+                   ::mcp-servers ::agent-infer? ::agent-skills ::agent-model]))
 
 (s/def ::custom-agents (s/coll-of ::custom-agent))
 

test/github/copilot_sdk/integration_test.clj

@@ -3356,6 +3356,57 @@
           agent (first (:customAgents create-params))]
       (is (= ["my-skill"] (:agentSkills agent))))))
 
+;; --- Per-agent model field (upstream PR #1309) ------------------------------
+
+(deftest test-custom-agent-model-spec
+  (testing "::custom-agent spec accepts optional :agent-model field"
+    (is (s/valid? :github.copilot-sdk.specs/custom-agent
+                  {:agent-name "test" :agent-prompt "You are helpful"}))
+    (is (s/valid? :github.copilot-sdk.specs/custom-agent
+                  {:agent-name "test" :agent-prompt "You are helpful"
+                   :agent-model "claude-haiku-4.5"}))
+    (is (not (s/valid? :github.copilot-sdk.specs/custom-agent
+                       {:agent-name "test" :agent-prompt "You are helpful"
+                        :agent-model 42}))
+        ":agent-model must be a string when provided")))
+
+(deftest test-custom-agent-model-on-wire
+  (testing "model field is sent on wire in session.create and session.resume (upstream PR #1309)"
+    (let [seen (atom {})
+          _ (mock/set-request-hook! *mock-server* (fn [method params]
+                                                    (when (#{"session.create" "session.resume"} method)
+                                                      (swap! seen assoc method params))))
+          _ (sdk/create-session *test-client*
+                                {:on-permission-request sdk/approve-all
+                                 :custom-agents [{:agent-name "haiku-agent"
+                                                  :agent-prompt "Hello"
+                                                  :agent-model "claude-haiku-4.5"}]})
+          session-id (sdk/get-last-session-id *test-client*)
+          _ (sdk/resume-session *test-client* session-id
+                                {:on-permission-request sdk/approve-all
+                                 :custom-agents [{:agent-name "haiku-agent-2"
+                                                  :agent-prompt "Hi"
+                                                  :agent-model "gpt-5.4"}]})
+          create-params (get @seen "session.create")
+          resume-params (get @seen "session.resume")]
+      (is (= "claude-haiku-4.5"
+             (get-in create-params [:customAgents 0 :agentModel])))
+      (is (= "gpt-5.4"
+             (get-in resume-params [:customAgents 0 :agentModel]))))))
+
+(deftest test-custom-agent-model-omitted-when-not-set
+  (testing ":agent-model is omitted from wire when not provided"
+    (let [seen (atom {})
+          _ (mock/set-request-hook! *mock-server* (fn [method params]
+                                                    (when (#{"session.create"} method)
+                                                      (swap! seen assoc method params))))
+          _ (sdk/create-session *test-client*
+                                {:on-permission-request sdk/approve-all
+                                 :custom-agents [{:agent-name "no-model"
+                                                  :agent-prompt "Hi"}]})
+          agent (first (get-in @seen ["session.create" :customAgents]))]
+      (is (not (contains? agent :agentModel))))))
+
 ;; --- Default agent config (upstream PR #1098) --------------------------------
 
 (deftest test-default-agent-excluded-tools-on-wire