Fix #528: non-TTY installer hardcodes the Claude agent

.surface

@@ -850,6 +850,7 @@ CMD basecamp search
 CMD basecamp search metadata
 CMD basecamp search types
 CMD basecamp setup
+CMD basecamp setup agents
 CMD basecamp setup claude
 CMD basecamp setup codex
 CMD basecamp show
@@ -11428,6 +11429,27 @@ FLAG basecamp setup --stats type=bool
 FLAG basecamp setup --styled type=bool
 FLAG basecamp setup --todolist type=string
 FLAG basecamp setup --verbose type=count
+FLAG basecamp setup agents --account type=string
+FLAG basecamp setup agents --agent type=bool
+FLAG basecamp setup agents --cache-dir type=string
+FLAG basecamp setup agents --count type=bool
+FLAG basecamp setup agents --help type=bool
+FLAG basecamp setup agents --hints type=bool
+FLAG basecamp setup agents --ids-only type=bool
+FLAG basecamp setup agents --in type=string
+FLAG basecamp setup agents --jq type=string
+FLAG basecamp setup agents --json type=bool
+FLAG basecamp setup agents --markdown type=bool
+FLAG basecamp setup agents --md type=bool
+FLAG basecamp setup agents --no-hints type=bool
+FLAG basecamp setup agents --no-stats type=bool
+FLAG basecamp setup agents --profile type=string
+FLAG basecamp setup agents --project type=string
+FLAG basecamp setup agents --quiet type=bool
+FLAG basecamp setup agents --stats type=bool
+FLAG basecamp setup agents --styled type=bool
+FLAG basecamp setup agents --todolist type=string
+FLAG basecamp setup agents --verbose type=count
 FLAG basecamp setup claude --account type=string
 FLAG basecamp setup claude --agent type=bool
 FLAG basecamp setup claude --cache-dir type=string
@@ -16470,6 +16492,7 @@ SUB basecamp search
 SUB basecamp search metadata
 SUB basecamp search types
 SUB basecamp setup
+SUB basecamp setup agents
 SUB basecamp setup claude
 SUB basecamp setup codex
 SUB basecamp show

e2e/installer.bats

@@ -0,0 +1,151 @@
+#!/usr/bin/env bats
+# installer.bats - Tests for the install scripts' post-install agent setup.
+#
+# #528: the non-TTY and skip branches must run `setup agents` (baseline skill +
+# best-effort agent connection), never the hardcoded `setup claude`. Old release
+# binaries (which lack `setup agents`) must fall back without reintroducing the
+# Claude-first bug.
+
+setup() {
+  # The installer contract keys off these; a leaked value would skew results.
+  unset BASECAMP_SKIP_SETUP BASECAMP_SETUP_AGENT
+
+  INSTALL_SH="${BATS_TEST_DIRNAME}/../scripts/install.sh"
+  INSTALL_PS1="${BATS_TEST_DIRNAME}/../scripts/install.ps1"
+
+  STUB_DIR="$(mktemp -d)"
+  LOG="$STUB_DIR/calls.log"
+  write_stub new  # default: a binary that supports `setup agents`
+}
+
+teardown() {
+  [[ -n "${STUB_DIR:-}" ]] && rm -rf "$STUB_DIR"
+}
+
+# write_stub emits a `basecamp` stub that logs its argv. mode=new advertises the
+# `setup agents` subcommand in `setup --help`; mode=old omits it and fails an
+# actual `setup agents` invocation, mimicking a pre-v0.7.3 release binary.
+write_stub() {
+  local mode="$1"
+  {
+    echo '#!/usr/bin/env bash'
+    echo "echo \"\$@\" >> \"$LOG\""
+    echo 'if [[ "$1 $2" == "setup --help" ]]; then'
+    echo '  echo "  claude  Install the Basecamp plugin for Claude Code"'
+    if [[ "$mode" == "new" ]]; then
+      echo '  echo "  agents  Install the Basecamp skill and connect detected coding agents"'
+    fi
+    echo '  exit 0'
+    echo 'fi'
+    if [[ "$mode" == "old" ]]; then
+      # A pre-`setup agents` binary advertises only `setup claude`. Reject every
+      # OTHER `setup <sub>`: the real old parent would swallow it as a stray arg
+      # and launch the interactive wizard — the exact bug the installer must avoid.
+      echo 'if [[ "$1" == "setup" && "$2" != "claude" && "$2" != "--help" ]]; then echo "unknown command \"$2\"" >&2; exit 1; fi'
+    fi
+    echo 'exit 0'
+  } > "$STUB_DIR/basecamp"
+  chmod +x "$STUB_DIR/basecamp"
+}
+
+run_post_install_setup() {
+  run bash -c "
+    set -euo pipefail
+    ${1:-}
+    source '$INSTALL_SH'
+    BIN_DIR='$STUB_DIR'
+    post_install_setup basecamp
+    cat '$LOG'
+  "
+}
+
+# The if-form guard must let sourcing define functions without running main.
+@test "install.sh can be sourced without running the installer" {
+  run bash -c "set -euo pipefail; source '$INSTALL_SH'; echo sourced-ok"
+  [[ "$status" -eq 0 ]]
+  [[ "$output" == *"sourced-ok"* ]]
+  [[ "$output" != *"Basecamp CLI"* ]]  # banner would print if main ran
+}
+
+@test "new binary: post_install_setup dispatches to 'setup agents', never 'setup claude'" {
+  run_post_install_setup
+  [[ "$status" -eq 0 ]]
+  [[ "$output" == *"setup agents"* ]]
+  [[ "$output" != *"setup claude"* ]]
+}
+
+@test "new binary: BASECAMP_SKIP_SETUP path still runs 'setup agents'" {
+  run_post_install_setup "export BASECAMP_SKIP_SETUP=1"
+  [[ "$status" -eq 0 ]]
+  [[ "$output" == *"setup agents"* ]]
+  [[ "$output" != *"setup claude"* ]]
+}
+
+# Cross-version regression: an old release binary (no `setup agents`) must NOT
+# silently fall back to Claude when the selector is unset — it installs the
+# shared skill only.
+@test "old binary + unset selector falls back to 'skill install', never 'setup claude'" {
+  write_stub old
+  run_post_install_setup
+  [[ "$status" -eq 0 ]]
+  [[ "$output" == *"skill install"* ]]
+  [[ "$output" != *"setup claude"* ]]
+  [[ "$output" != *"setup agents"$'\n'* ]]  # the unknown command is never left as the outcome
+}
+
+@test "old binary + BASECAMP_SETUP_AGENT=claude connects claude explicitly" {
+  write_stub old
+  run_post_install_setup "export BASECAMP_SETUP_AGENT=claude"
+  [[ "$status" -eq 0 ]]
+  [[ "$output" == *"setup claude"* ]]
+  [[ "$output" != *"skill install"* ]]
+}
+
+# Explicit `all` intent must dispatch every per-agent setup the old binary
+# supports (here the stub advertises only `claude`), never collapse to skill-only.
+@test "old binary + BASECAMP_SETUP_AGENT=all runs the supported per-agent setups" {
+  write_stub old
+  run_post_install_setup "export BASECAMP_SETUP_AGENT=all"
+  [[ "$status" -eq 0 ]]
+  [[ "$output" == *"setup claude"* ]]
+  [[ "$output" != *"setup codex"* ]]  # codex unadvertised → never invoked
+}
+
+# Explicit `codex` on an old binary that lacks `setup codex` must NOT run the
+# unknown subcommand (which would launch the interactive wizard) — it degrades
+# to the shared skill.
+@test "old binary + BASECAMP_SETUP_AGENT=codex degrades to 'skill install', never 'setup codex'" {
+  write_stub old
+  run_post_install_setup "export BASECAMP_SETUP_AGENT=codex"
+  [[ "$status" -eq 0 ]]
+  [[ "$output" == *"skill install"* ]]
+  [[ "$output" != *"setup codex"* ]]
+}
+
+@test "install.sh has no residual 'setup claude' dispatch" {
+  # `setup claude` may appear only inside the explicit-selector fallback case.
+  run grep -n 'setup claude' "$INSTALL_SH"
+  [[ "$status" -ne 0 ]]  # no literal `setup claude` string in the script
+}
+
+@test "install.sh skip and non-tty branches both dispatch via post_install_setup" {
+  run grep -c 'post_install_setup "\$binary_name"' "$INSTALL_SH"
+  [[ "$status" -eq 0 ]]
+  [[ "$output" -ge 2 ]]
+}
+
+@test "install.ps1 routes both branches through the guarded best-effort helper" {
+  run grep -c 'Invoke-PostInstallSetup \$installedBinary' "$INSTALL_PS1"
+  [[ "$status" -eq 0 ]]
+  [[ "$output" -eq 2 ]]
+}
+
+@test "install.ps1 helper is guarded and cross-version aware" {
+  grep -q 'function Invoke-PostInstallSetup' "$INSTALL_PS1"
+  grep -q 'setup agents' "$INSTALL_PS1"
+  grep -q 'skill install' "$INSTALL_PS1"
+  grep -q 'catch {' "$INSTALL_PS1"
+  # Explicit claude|codex selectors must be capability-checked before dispatch,
+  # so an old binary never gets an unadvertised subcommand as a stray arg.
+  grep -qF 'match "(?m)^\s+$selector\s"' "$INSTALL_PS1"
+}

e2e/smoke/smoke_lifecycle.bats

@@ -32,6 +32,10 @@ load smoke_helper
   mark_out_of_scope "Modifies Claude Code config"
 }
 
+@test "setup agents is out of scope" {
+  mark_out_of_scope "Modifies coding-agent config"
+}
+
 @test "quick-start is out of scope" {
   mark_out_of_scope "Interactive onboarding wizard"
 }

install.md

@@ -2,6 +2,8 @@
 
 Install the Basecamp CLI and connect it to your AI agent. Execute all steps autonomously.
 
+The piped installer (Step 1) already installs the baseline agent skill and, on a best-effort basis, attempts to connect a single detected coding agent. The optional "Connect Your Agent" section below is for forcing a specific agent, handling multiple detected agents, or verifying the connection.
+
 **DONE WHEN:** `basecamp --version && basecamp auth status` both succeed.
 
 ---
@@ -10,7 +12,7 @@ Install the Basecamp CLI and connect it to your AI agent. Execute all steps auto
 
 - [ ] Install Basecamp CLI
 - [ ] Authenticate with Basecamp
-- [ ] Connect agent (optional)
+- [ ] Connect agent (optional — the piped installer already attempts one detected agent)
 
 ---
 
@@ -28,7 +30,11 @@ curl -fsSL https://basecamp.com/install-cli | bash
 irm https://raw.githubusercontent.com/basecamp/basecamp-cli/main/scripts/install.ps1 | iex
 ```
 
-> **Note:** The install scripts auto-detect non-interactive environments (CI, piped input, coding agents) and skip the interactive setup wizard. You can also explicitly skip it with `BASECAMP_SKIP_SETUP=1`.
+> **Note:** The install scripts auto-detect non-interactive environments (CI, piped input, coding agents) and skip the interactive setup wizard. In that case they still run `basecamp setup agents`, which installs the baseline agent skill and **attempts to connect** a single detected coding agent (best effort). If several agents are detected, or none is, only the baseline skill is installed and the per-agent commands are surfaced. Explicitly skipping the wizard with `BASECAMP_SKIP_SETUP=1` still runs `setup agents`.
+>
+> Choose which agent to connect with `BASECAMP_SETUP_AGENT` (`claude`, `codex`, `all`, or `none`). Set it for the interpreter, not the fetch:
+> - Bash: `curl -fsSL https://basecamp.com/install-cli | BASECAMP_SETUP_AGENT=codex bash`
+> - PowerShell: `$env:BASECAMP_SETUP_AGENT='codex'; irm https://raw.githubusercontent.com/basecamp/basecamp-cli/main/scripts/install.ps1 | iex`
 >
 > **Windows note:** if `curl` fails with a `schannel` / `CRYPT_E_NO_REVOCATION_CHECK` TLS error, prefer the PowerShell installer, Scoop, or Git Bash's `/usr/bin/curl` instead of the system `curl.exe`.
 
@@ -112,7 +118,7 @@ EXECUTE NOW: Start with Step 1. Mark TODO items complete as you go. Stop when `b
 
 **Do not execute this section unless explicitly requested.** The core installation is complete when DONE WHEN passes.
 
-Both agent plugins require the `basecamp` CLI installed above — the plugin invokes it for every Basecamp operation.
+The piped installer (Step 1) already installs the baseline skill and attempts to connect a single detected agent. Run the commands here to force a specific agent, connect a second one, or when several agents were detected and the installer connected none. Both agent plugins require the `basecamp` CLI installed above — the plugin invokes it for every Basecamp operation.
 
 ### Claude Code
 

internal/commands/auth.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"sort"
 	"strings"
 	"time"
 
@@ -332,18 +333,38 @@ func buildLogoutCmd(use string) *cobra.Command {
 }
 
 // printAgentNudge prints a hint about coding agent setup after login.
+//
+// Detection proves presence, not intent: with a single detected-unhealthy agent
+// it points at that agent; with several, it never guesses — it prints every
+// `basecamp setup <id>` choice so the user picks.
 func printAgentNudge(w io.Writer, r *output.Renderer) {
+	type nudgeAgent struct{ id, name string }
+	var unhealthy []nudgeAgent
 	for _, agent := range harness.DetectedAgents() {
 		if agent.Checks == nil {
 			continue
 		}
 		for _, c := range agent.Checks() {
 			if c.Status != "pass" {
-				fmt.Fprintln(w)
-				fmt.Fprintln(w, r.Muted.Render(fmt.Sprintf("  %s detected. Connect it to Basecamp:", agent.Name)))
-				fmt.Fprintln(w, r.Data.Render(fmt.Sprintf("  basecamp setup %s", agent.ID)))
-				return // one nudge is enough
+				unhealthy = append(unhealthy, nudgeAgent{id: agent.ID, name: agent.Name})
+				break
 			}
 		}
 	}
+	sort.Slice(unhealthy, func(i, j int) bool { return unhealthy[i].id < unhealthy[j].id })
+
+	switch len(unhealthy) {
+	case 0:
+		return
+	case 1:
+		fmt.Fprintln(w)
+		fmt.Fprintln(w, r.Muted.Render(fmt.Sprintf("  %s detected. Connect it to Basecamp:", unhealthy[0].name)))
+		fmt.Fprintln(w, r.Data.Render(fmt.Sprintf("  basecamp setup %s", unhealthy[0].id)))
+	default:
+		fmt.Fprintln(w)
+		fmt.Fprintln(w, r.Muted.Render("  Multiple coding agents detected. Choose one:"))
+		for _, a := range unhealthy {
+			fmt.Fprintln(w, r.Data.Render(fmt.Sprintf("  basecamp setup %s", a.id)))
+		}
+	}
 }

internal/commands/auth_test.go

@@ -0,0 +1,63 @@
+package commands
+
+import (
+	"bytes"
+	"io"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/basecamp/basecamp-cli/internal/output"
+)
+
+// nudgeOutput runs printAgentNudge against a non-styled renderer and returns
+// the plain text written for the login hint.
+func nudgeOutput(t *testing.T) string {
+	t.Helper()
+	buf := &bytes.Buffer{}
+	printAgentNudge(buf, output.NewRenderer(io.Discard, false))
+	return buf.String()
+}
+
+// TestPrintAgentNudgeNoneDetected: no detected agent → no nudge.
+func TestPrintAgentNudgeNoneDetected(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	t.Setenv("PATH", filepath.Join(home, "empty-bin"))
+
+	assert.Empty(t, nudgeOutput(t))
+}
+
+// TestPrintAgentNudgeSingle: one detected-unhealthy agent → its `setup <id>`.
+func TestPrintAgentNudgeSingle(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	t.Setenv("PATH", filepath.Join(home, "empty-bin"))
+	require.NoError(t, os.MkdirAll(filepath.Join(home, ".codex"), 0o755))
+
+	out := nudgeOutput(t)
+
+	assert.Contains(t, out, "Codex detected")
+	assert.Contains(t, out, "basecamp setup codex")
+	assert.NotContains(t, out, "basecamp setup claude")
+}
+
+// TestPrintAgentNudgeMultiple: ≥2 detected-unhealthy → every choice printed
+// directly (never Claude-first, never routed to `setup agents`).
+func TestPrintAgentNudgeMultiple(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	t.Setenv("PATH", filepath.Join(home, "empty-bin"))
+	require.NoError(t, os.MkdirAll(filepath.Join(home, ".claude"), 0o755))
+	require.NoError(t, os.MkdirAll(filepath.Join(home, ".codex"), 0o755))
+
+	out := nudgeOutput(t)
+
+	assert.Contains(t, out, "Multiple coding agents detected")
+	assert.Contains(t, out, "basecamp setup claude")
+	assert.Contains(t, out, "basecamp setup codex")
+	assert.NotContains(t, out, "basecamp setup agents")
+}