Claude Code 2.1.144 adds `/resume` for background sessions and fixes 75s startup hangs

• ClaudeCodeLog's release post says Claude Code 2.1.144 ships 52 CLI changes, led by /resume support for background sessions and a switch to grep-backed system search.
• According to ClaudeCodeLog's changelog thread, the biggest user-facing fixes are a startup stall that could last up to 75 seconds, long-session terminal corruption, and several background-session regressions.
• ClaudeCodeLog's follow-up post adds a quieter but important prompt change: the edit tool is now explicitly described as doing exact string replacements, and the release adds four new env vars plus a claude-in-chrome model slug.
• The background-session changes line up with a real annoyance that LLMpsycho described earlier, keeping model and effort settings so a resumed session does not make users restate how hard to think.

You can read the official 2.1.144 changelog, inspect the CLI surface diff, and the release also sneaks in a claude-in-chrome model slug plus four new env vars in ClaudeCodeLog's diff summary. The thread is unusually dense for a point release: ClaudeCodeLog's changelog post lists fixes for paginated MCP tool discovery, Bedrock and Vertex model selection, malformed image handling, and background-service wakeups.

The headliner is /resume for background sessions. Sessions started with claude --bg or from agent view now show up beside interactive sessions, marked bg, and background subagent completions now include elapsed time.

The same part of the release cleans up how those sessions persist state. According to ClaudeCodeLog's changelog thread, resumed sessions now keep their existing model instead of inheriting another session's /model choice, while /bg and detach also preserve directories added via /add-dir.

That sounds small until you pair it with LLMpsycho's complaint about waking a session and having to restate model and effort settings. Claude Code is converging on background work as something you return to, not something you restart from memory.

Two changes here are about reproducibility more than features. ClaudeCodeLog's release post says system searches now use grep for consistent, file-based results, and ClaudeCodeLog's follow-up post says the edit tool prompt now explicitly promises exact string replacement.

In practice, the release tightens three behaviors:

• Search uses grep-backed file results, per ClaudeCodeLog's release post.
• Edit is framed as exact string replacement, per ClaudeCodeLog's follow-up post.
• A no-match exit code from egrep, fgrep, git grep, or git diff no longer shows up as a command failure, according to ClaudeCodeLog's changelog thread.

That is a pretty clear bias toward making tool behavior more deterministic inside agent loops.

Most of the 52 changes are cleanup, but a lot of them land on failure modes that would poison long runs. ClaudeCodeLog's changelog thread says startup side-channel API calls now time out after 15 seconds instead of hanging up to 75 seconds when api.anthropic.com is unreachable.

The same post groups a messy set of terminal bugs into one release: missed resize events no longer require Ctrl+L, progressive glyph corruption in very long sessions now self-heals, Windows background-session scrolling works again, and closing the terminal while attached no longer crashes the client.

MCP also gets a real reliability pass. According to ClaudeCodeLog's changelog thread, paginated tools/list responses no longer drop everything after page one, unsupported image MIME types like SVG now get saved to disk and referenced instead of breaking the conversation, and claude mcp list now reports parse errors instead of pretending there are no servers.

The follow-up diff is where the release gets stranger. ClaudeCodeLog's diff summary says 2.1.144 landed just 3 days, 1 hour, 4 minutes, and 35 seconds after 2.1.143, added four prompt files, and increased prompt tokens by 7,681, or 13.6 percent.

It also lists a few concrete additions that the main changelog does not foreground:

• New env vars: CCR_SPAWN_TIMESTAMP_MS, CLAUDE_CODE_ALT_SCREEN_FULL_REPAINT, CLAUDE_PTY_HOST_EXEC, CLAUDE_SECURESTORAGE_CONFIG_DIR, per ClaudeCodeLog's diff summary.
• New model slug: claude-in-chrome, per ClaudeCodeLog's diff summary.
• Prompt mix shift: tool tokens rose from 54.6 percent to 60.0 percent, while system and reminder shares fell, per ClaudeCodeLog's diff summary.

For a low-key patch, that is a meaningful amount of prompt and surface-area churn packed around a bug-fix release.