A small change in Claude Code v2.1.185 has an outsized impact for anyone running long, complex, or multi-agent sessions: the stream-stall detection timeout has been doubled from 10 seconds to 20 seconds.

It’s a one-line change in substance, but it meaningfully reduces the rate of premature retries that have frustrated developers running sophisticated agentic workflows.

What Changed in v2.1.185

Claude Code uses client-side stream-stall detection to figure out when an API response has gone silent. When SSE tokens stop arriving for a certain amount of time, the client assumes something has gone wrong and retries the request.

In v2.1.185, two things changed:

  1. The silence threshold increased from 10s to 20s — the client now waits twice as long before deciding the stream has stalled
  2. The status message is clearer — instead of the previous "No response from API · Retrying in…", users now see "Waiting for API response · will retry…"

The new message is more accurate: it reflects that the client is actively waiting on the API rather than assuming failure has already occurred.

Why This Matters for Multi-Agent Workflows

If you’re running multi-agent setups — orchestrators spawning subagents, parallel task runners, or sessions with heavy tool use — you’ve likely hit this before. The scenario goes like this:

  1. Your agent invokes a tool or delegates to a subagent
  2. The operation takes longer than 10 seconds to return (maybe it’s hitting a slow API, doing a database lookup, or the LLM is generating a very long response)
  3. Claude Code decides the stream has stalled and retries
  4. Now you have duplicate requests in flight — or worse, a partially-completed operation that gets re-attempted

With the 20-second threshold, legitimate slow operations are far less likely to trigger a false stall detection. The change is particularly beneficial for:

  • Complex tool chains with multiple sequential API calls
  • Agentic tasks involving file system operations or database queries
  • Sessions run on slower hardware or through network proxies
  • Long-context generation where the model is producing lengthy structured output

What Stays the Same

This is a client-side change only. It does not affect Anthropic’s backend streaming behavior or the actual retry logic (still exponential backoff, default max 10 retries). The environment variable CLAUDE_CODE_MAX_RETRIES still lets you tune retry counts.

It also doesn’t change anything about how the API handles the actual requests — this is purely about when Claude Code decides to initiate a retry.

Common Causes of Stream Stalls

If you’re seeing the stall message frequently even after this update, common culprits include:

  • Network instability — particularly on VPNs or unreliable connections
  • Proxy interference — corporate proxies can buffer SSE streams unexpectedly
  • Very complex tool use — operations that require extensive model reasoning before responding
  • Temporary API slowdowns — Anthropic’s infrastructure occasionally runs slower during peak periods

Upgrading to v2.1.185 gives your sessions more breathing room to complete legitimate long-running operations before the retry fires.

How to Check Your Version

If you’re using Claude Code and want to verify you’re on v2.1.185 or later:

# Check installed Claude Code version
# Refer to official Claude Code documentation for the exact version command

Keep Claude Code updated via your package manager to receive reliability improvements as they ship.

The Bigger Picture

This change reflects a broader maturation of Claude Code’s multi-agent story. Earlier versions were optimized for quick, interactive sessions. As the tool is increasingly used for long-running autonomous workflows — background agents, pipeline stages, overnight batch jobs — the defaults need to accommodate that reality.

Doubling the stall timeout is exactly the kind of pragmatic adjustment that shows the team is paying attention to how developers are actually using the tool in production. It’s not glamorous, but it’s the kind of fix that makes complex agentic systems meaningfully more reliable.

Sources

  1. Claude Code Releases — GitHub (anthropics/claude-code)
  2. @ClaudeCodeLog — X/Twitter (community changelog)
  3. Claude Code Error Handling Documentation — code.claude.com

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