From 64c259c3e87fb193fa24bc70abc03df58d3f58e2 Mon Sep 17 00:00:00 2001
From: Claude <noreply@anthropic.com>
Date: Sun, 6 Sep 2026 15:16:11 +0000
Subject: [PATCH] fix(cli): fresh path keeps auto -> anyrouter/auto for
 first-turn failover (#58)
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anyr claude with no --model now leaves ANYROUTER_MODEL_MODE=auto and
ANTHROPIC_MODEL=anyrouter/auto on a fresh install, instead of pinning the
most-used catalog model id. Pinning a single model disables anyrouter/auto's
health-aware cross-model failover chain — the first turn can then land on a
degraded SKU with no fallback.

The /models lookup still contributes the context-window probe used for
Claude's 1M-context suffix. most_used_model_id is retained for the models
list UI, which still shows the user's pinned auto model.

Docs: clarify --model auto default in help text.
---
 src/cmd/launch.rs | 15 ++++++++-------
 src/help.rs       |  5 ++++-
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/src/cmd/launch.rs b/src/cmd/launch.rs
index e77fea4..fbd1430 100644
--- a/src/cmd/launch.rs
+++ b/src/cmd/launch.rs
@@ -2,7 +2,7 @@ use std::collections::BTreeMap;
 
 use crate::auth::acquire_api_key;
 use crate::config::{write_config, DEFAULT_PROFILE};
-use crate::http::{fetch_models, most_used_model_id};
+use crate::http::fetch_models;
 use crate::install::ensure_tool_installed;
 use crate::key::{
     load_config_if_present, profile_for_agent, resolve_base_url, resolve_launch_api_key,
@@ -44,14 +44,15 @@ pub(crate) fn resolve_session_model(
             context_window: None,
         };
     };
-    let id = if is_auto_model(&requested) {
-        most_used_model_id(&models).unwrap_or(requested)
-    } else {
-        requested
-    };
+    // Keep `auto` / `anyrouter/auto` as-is so the gateway applies the full
+    // preset failover chain on the first turn — pinning a single concrete model
+    // here would defeat anyrouter/auto's cross-model failover (north star:
+    // "fewer models that work"). The live `/models` lookup still contributes the
+    // context-window probe used for Claude's 1M-context suffix decision below.
+    let id = requested;
     let context_window = models
         .iter()
-        .find(|m| catalog_model_id(&m.id) == id)
+        .find(|m| is_auto_model(&m.id))
         .and_then(|m| m.context_length);
     ResolvedModel { id, context_window }
 }
diff --git a/src/help.rs b/src/help.rs
index c482879..c76bbfb 100644
--- a/src/help.rs
+++ b/src/help.rs
@@ -12,7 +12,10 @@ Launches the coding agent through AnyRouter (signs in first if needed).
 
 Options:
   --yes, --ok           Skip confirmation prompts (login / install)
-  --model auto|<id>     Session model. \"auto\" picks the most-used catalog model
+  --model auto|<id>     Session model. Default (no flag) = \"auto\" → \
+anyrouter/auto on a fresh install; \"auto\" resolves to the most-used \
+catalog model on an authed key, else anyrouter/auto. Omit to let failover \
+pick the best stable model per turn.
   --haiku <id>          Claude /model haiku and subagents
   --sonnet <id>         Claude /model sonnet
   --opus <id>           Claude /model opus