[2026-04-09] Model choice for 3P agents (#60690)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: timrogers <116134+timrogers@users.noreply.github.com>
Co-authored-by: Tim Rogers <timrogers@github.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Sarita Iyer <66540150+saritai@users.noreply.github.com>

Author: 4 people

content/copilot/concepts/agents/about-third-party-agents.md

@@ -45,6 +45,24 @@ The following third-party agents are supported on {% data variables.product.gith
 * [{% data variables.product.prodname_anthropic_claude %}](/copilot/concepts/agents/anthropic-claude)
 * [{% data variables.product.prodname_openai_codex %}](/copilot/concepts/agents/openai-codex)
 
+## AI models for third-party agents
+
+When starting a task with a third-party agent, you can select the AI model used by the agent. You may find that different models perform better, or provide more useful responses, depending on the type of task. For help deciding which model to use, see [AUTOTITLE](/copilot/reference/ai-models/model-comparison).
+
+You can also select **Auto**, which allows {% data variables.copilot.copilot_auto_model_selection %} to choose the best available model on your behalf. For more information, see [AUTOTITLE](/copilot/concepts/auto-model-selection).
+
+The following models are available for each agent:
+
+### {% data variables.product.prodname_openai_codex %}
+
+* Auto
+{% data reusables.copilot.openai-codex-agent-models %}
+
+### {% data variables.product.prodname_anthropic_claude %}
+
+* Auto
+{% data reusables.copilot.anthropic-claude-agent-models %}
+
 ## Usage costs
 
 Coding agents consume **{% data variables.product.prodname_actions %} minutes** and **{% data variables.product.prodname_copilot %} premium requests**. Each agent **session** consumes one premium request.

content/copilot/concepts/agents/anthropic-claude.md

@@ -19,3 +19,12 @@ The {% data variables.product.prodname_anthropic_claude %} coding agent uses the
 Before you can assign tasks to {% data variables.product.prodname_anthropic_claude %} coding agent, it must be enabled. See [AUTOTITLE](/copilot/how-tos/manage-your-account/manage-policies#enabling-or-disabling-third-party-agents-in-your-repositories). 
 
 To learn more about using third-party coding agents, see [AUTOTITLE](/copilot/concepts/agents/about-third-party-agents).
+
+### Supported models
+
+When starting a task with the {% data variables.product.prodname_anthropic_claude %} coding agent, you can select the AI model used by the agent. The following models are available:
+
+* Auto
+{% data reusables.copilot.anthropic-claude-agent-models %}
+
+If you select **Auto**, {% data variables.copilot.copilot_auto_model_selection %} will select the best model based on availability and to help reduce rate limiting. For more information, see [AUTOTITLE](/copilot/concepts/auto-model-selection).

content/copilot/concepts/agents/openai-codex.md

@@ -23,6 +23,15 @@ Before you can assign tasks to {% data variables.product.prodname_openai_codex %
 
 To learn more about using third-party agents on {% data variables.product.github %}, see [AUTOTITLE](/free-pro-team@latest/copilot/concepts/agents/about-third-party-agents).
 
+### Supported models
+
+When starting a task with the {% data variables.product.prodname_openai_codex %} coding agent, you can select the AI model used by the agent. The following models are available:
+
+* Auto
+{% data reusables.copilot.openai-codex-agent-models %}
+
+If you select **Auto**, {% data variables.copilot.copilot_auto_model_selection %} will select the best model based on availability and to help reduce rate limiting. For more information, see [AUTOTITLE](/copilot/concepts/auto-model-selection).
+
 ## {% data variables.product.prodname_vscode_shortname %} extension
 
  Use "Sign in with {% data variables.product.prodname_copilot_short %}" when launching the extension. {% data variables.product.prodname_copilot_short %} users can see this integration in the [Agent Sessions view](https://code.visualstudio.com/docs/copilot/chat/chat-sessions#_agent-sessions-view) in {% data variables.product.prodname_vscode_shortname %} Insiders along with progress on their running tasks. All usage is subject to {% data variables.product.github %} rate limits and billing. See [AUTOTITLE](/copilot/concepts/billing/copilot-requests#premium-features).

content/copilot/concepts/auto-model-selection.md

@@ -2,7 +2,7 @@
 title: 'About {% data variables.product.prodname_copilot_short %} auto model selection'
 allowTitleToDifferFromFilename: true
 shortTitle: 'Auto model selection'
-intro: 'Automatically select models for {% data variables.copilot.copilot_chat_short %} and {% data variables.copilot.copilot_cloud_agent %}.'
+intro: 'Automatically select models for {% data variables.copilot.copilot_chat_short %}, {% data variables.copilot.copilot_cloud_agent %}, and third-party agents.'
 product: '{% data variables.copilot.copilot_auto_model_selection_short_cap_a %} for {% data variables.copilot.copilot_chat_short %} is available with all {% data variables.product.prodname_copilot %} plans. <br>{% data variables.copilot.copilot_auto_model_selection_short_cap_a %} for {% data variables.copilot.copilot_cloud_agent %} is available for {% data variables.copilot.copilot_pro %} and {% data variables.copilot.copilot_pro_plus %} plans.'
 versions:
   feature: copilot
@@ -66,3 +66,19 @@ When you select **Auto** in {% data variables.copilot.copilot_cloud_agent %}, {%
   {% data reusables.copilot.copilot-cloud-agent-auto-models %}
 
 {% data reusables.copilot.change-the-ai-model-copilot-cloud-agent %}
+
+## {% data variables.copilot.copilot_auto_model_selection_short_cap_a %} in {% data variables.product.prodname_openai_codex %}
+
+When you select **Auto** in the {% data variables.product.prodname_openai_codex %} coding agent, {% data variables.copilot.copilot_auto_model_selection_short_cap_a %} currently chooses from the following list of models, subject to your policies and subscription type:
+
+{% data reusables.copilot.openai-codex-agent-models %}
+
+For more information, see [AUTOTITLE](/copilot/concepts/agents/openai-codex).
+
+## {% data variables.copilot.copilot_auto_model_selection_short_cap_a %} in {% data variables.product.prodname_anthropic_claude %}
+
+When you select **Auto** in the {% data variables.product.prodname_anthropic_claude %} coding agent, {% data variables.copilot.copilot_auto_model_selection_short_cap_a %} currently chooses from the following list of models, subject to your policies and subscription type:
+
+{% data reusables.copilot.anthropic-claude-agent-models %}
+
+For more information, see [AUTOTITLE](/copilot/concepts/agents/anthropic-claude).

data/reusables/copilot/anthropic-claude-agent-models.md

@@ -0,0 +1,4 @@
+* {% data variables.copilot.copilot_claude_opus_45 %}
+* {% data variables.copilot.copilot_claude_opus_46 %}
+* {% data variables.copilot.copilot_claude_sonnet_45 %}
+* {% data variables.copilot.copilot_claude_sonnet_46 %}

data/reusables/copilot/openai-codex-agent-models.md

@@ -0,0 +1,3 @@
+* {% data variables.copilot.copilot_gpt_52_codex %}
+* {% data variables.copilot.copilot_gpt_53_codex %}
+* {% data variables.copilot.copilot_gpt_54 %}