Anthropic Releases Claude Code v2.1.295 with Strict Hook Controls, Gateway Filters, and MCP Fixes

What changed#

Anthropic has released Claude Code v2.1.295, bringing stricter execution controls for automated hooks, expanded enterprise gateway settings, and critical bug fixes for Model Context Protocol (MCP) integrations.

Key additions and fixes in this release include:

• Hook Failure Safeguards: Command and HTTP hooks now support onFailure: "block". If a configured hook fails to start, times out, or exits with an unexpected code, Claude Code explicitly halts the downstream action instead of letting it execute.
• Gateway Upstream Model Routing and Timeouts: Enterprise gateway upstream configurations now support an optional models array with wildcard (*) matching to restrict which models route to specific backends. Upstreams on Amazon Bedrock, Google Vertex AI, Palantir Foundry, and others can set timeouts.upstream_ttfb_ms to bound initial stream response times before triggering failover or returning a 502 status. Unmanaged environments can enforce custom gateway logins via forceLoginMethod: "gateway" and forceLoginGatewayUrl in user settings.
• Audit Traceability: Gateway inference audit events now output upstream_request_id (sourced from Bedrock, Anthropic, or other upstreams), and successful gateway responses append a matching request-id header to align local telemetry with backend logs.
• Terminal and UI Enhancements: Added support for the Program Status Protocol (OSC 7501) to signal terminal emulators whether Claude Code is active, waiting, or finished. Mods gain $.ui.notify for native system notifications and expanded Button support accepting nested strings and Text children.
• Retry Watchdog Limits: Introduced CLAUDE_CODE_RETRY_WATCHDOG_MAX_WAIT_MS to cap how long unattended watchdog retries wait during persistent 429 and 529 provider rate-limit errors.
• Automatic 1M Context Fallback: If a proxy, Bedrock, Vertex, or Foundry upstream rejects the [1m] extended context beta, Claude Code automatically resends the prompt without the beta header rather than throwing an error.
• MCP and Agent Process Fixes: Remote MCP connections in headless and SDK modes now use exponential backoff (up to 30 seconds) on repeated drops instead of thrashing reconnect loops. Fixed file extension classification so MCP tools returning CSS, JS, XML, fonts, or icons are no longer stored as .bin files. Addressed a timing bug in CLAUDE_AUTO_BACKGROUND_TASKS where subagents were moved to the background before queued edit or shell calls completed.

Why it matters#

Configuring automated agent actions requires deterministic safeguards. Prior to this update, a failed pre-execution validation hook could silently let commands run. Supporting onFailure: "block" closes this gap, continuing the trend of enterprise controls seen in earlier plugin mods and protocol updates.

For teams deploying Claude Code through private API gateways or multi-cloud infrastructure, fine-grained model routing arrays and explicit time-to-first-byte limits prevent hanging requests and model mismatches across Bedrock and Vertex backends. Syncing upstream_request_id across response headers and telemetry event streams also simplifies tracing failure modes in production.

Finally, the MCP stability fixes resolve connection churn during temporary network outages, building on previous session stability and telemetry improvements.

What to do next#

1. Update the CLI: Install or update to v2.1.295 through your preferred package manager.
2. Enforce Hook Fail-Closed Rules: Update command and HTTP hook definitions in your project configuration to include onFailure: "block" for security-critical steps.
3. Configure Gateway Upstreams: If running a custom proxy gateway, update your upstream definitions with specific models lists and define timeouts.upstream_ttfb_ms to manage backend failover behavior.
4. Set Unattended Watchdog Limits: Define CLAUDE_CODE_RETRY_WATCHDOG_MAX_WAIT_MS in headless CI/CD environments to prevent automated agent runs from blocking indefinitely during extended upstream outages.

Sources#

• Claude Code v2.1.295 Release Notes