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Claude Code 2.1.94 to 2.1.97: Mantle for Bedrock, Focus View, and a Fat MCP Memory Leak Patched

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Three releases in two days: Claude Code adds Bedrock via Mantle, a new focus view mode, higher default effort levels — and an MCP bug that was burning 50 MB an hour is finally gone.

Claude Code Release MCP Bedrock NO_FLICKER
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Claude Code shipped three releases back to back over the last 48 hours: 2.1.94 on April 7, then 2.1.96 and finally 2.1.97 on April 8. Sandwiched in there is a Bedrock regression hotfix and a stack of bugs that were clearly hurting people right now.

Highlights from 2.1.94

  • Amazon Bedrock via Mantle: With CLAUDE_CODE_USE_MANTLE=1, Claude Code now talks to Bedrock through Mantle — a clear nod to enterprise customers who have to keep everything inside AWS.
  • Default effort bumped to high: For API key, Bedrock, Vertex, Foundry, Team and Enterprise users, the default effort level moves from medium to high. More tokens, but better results out of the box.
  • Cleaner Slack MCP: Slack tool calls get a compact Slacked #channel header — small UI detail, big quality-of-life improvement.
  • Various fixes: agents stuck after 429 rate limits; Console login on macOS silently failing because of keychain issues; plugin skill hooks defined in YAML frontmatter being ignored.

2.1.96 — the quick hotfix

One issue only: Bedrock requests were dying with 403 'Authorization header is missing' when using AWS_BEARER_TOKEN_BEDROCK or CLAUDE_CODE_SKIP_BEDROCK_AUTH. A regression from 2.1.94, now clean.

2.1.97 — focus view and memory hygiene

The most interesting update is in 2.1.97:

  • Focus view toggle: Ctrl+O now opens a focused view in NO_FLICKER mode.
  • Live subagent indicator: /agents shows ● N running for active subagents.
  • Cedar syntax highlighting: .cedar and .cedarpolicy files are now recognized — small feature, but relevant if you live in AWS IAM land.
  • The big fix: MCP HTTP/SSE connections were leaking around 50 MB of unreleased buffers per hour. The kind of bug that runs for a long time before anyone notices — patched.
  • 429 retries no longer burn all attempts too quickly (better exponential backoff).
  • --dangerously-skip-permissions is no longer silently downgraded after approving writes to protected paths.
  • NO_FLICKER mode: memory leaks, scroll render artifacts and Unicode corruption fixed.

My take

2.1.97 is one of those releases that doesn’t look flashy from the outside but makes long-running sessions noticeably less painful. If you keep Claude Code open for hours — plan mode, cloud agents, MCP servers humming in the background — you’ll feel that 50 MB bug. Nice to see Anthropic shipping polish releases instead of pushing only feature work.

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