`multiagents setup` does not propagate MULTIAGENTS_PORT into codex/claude/gemini config

[papajade55-debug]

Summary

When the user exports a custom MULTIAGENTS_PORT in the environment before running multiagents setup, the setup correctly starts the broker on that port, but does not write the port back into the agent configuration files. As a result, the configured agents (Claude Code, Codex CLI, Gemini CLI) will connect to the default :7899 broker instead of the one the user intended.

Related to (but not the same as) #1, which fixed orchestrator-server.ts to honor MULTIAGENTS_PORT. This issue is about setup / install-mcp.

Reproduction

# State before: clean codex config (no multiagents section)
grep -c "mcp_servers.multiagents" ~/.codex/config.toml
# → 0

# Run setup with a non-default port
MULTIAGENTS_PORT=7900 multiagents setup
# → Broker starts on :7900 (correct)

# Check what ended up in the agent config
grep -A5 "mcp_servers.multiagents" ~/.codex/config.toml

Actual output:

[mcp_servers.multiagents]
command = "/usr/bin/bun"
args = ["/home/.../multiagents/server.ts", "--agent-type", "codex"]
default_approval_mode = "approve"

Expected output (when MULTIAGENTS_PORT is set in env):

[mcp_servers.multiagents]
command = "/usr/bin/bun"
args = ["/home/.../multiagents/server.ts", "--agent-type", "codex"]
default_approval_mode = "approve"
env = { MULTIAGENTS_PORT = "7900" }

The same gap exists for Claude Code (~/.claude.json → mcpServers.multiagents.env) and Gemini CLI (~/.gemini/settings.json → mcpServers.multiagents.env).

Impact

Users who run two brokers side by side (e.g. a legacy broker on :7899 and multiagents on :7900 during a migration window) see their agents silently connect to the wrong broker, producing symptoms like:

• list_peers returns empty
• send_message looks like it succeeded but teammates never see the message
• Orchestrator /sessions/* returns 404 (the exact scenario that fix(orchestrator): honor MULTIAGENTS_PORT env var for broker URL #1 patched)

Suggested fix

In cli/install-mcp.ts:

1. Detect process.env.MULTIAGENTS_PORT at setup time.
2. In upsertCodexMultiagentsSection, append an env entry when the port differs from DEFAULT_BROKER_PORT.
3. Same for the Claude and Gemini JSON writers — already easier since both configs already support env.

Happy to submit a PR if you want — just wanted to flag it first since the fix surface touches three writers.

Environment

• multiagents@0.4.8 (npm)
• Linux Mint 22.3 / Ubuntu 24.04 noble
• Bun 1.3.9
• Codex CLI 0.122.0, Claude Code 2.1.116, Gemini CLI 0.38.2