Anthropic API / Anthropic API

Streaming /v1/messages Drops Mid-Stream With RemoteProtocolError on Long Runs

Fix intermittent streaming disconnections (RemoteProtocolError) on long-running /v1/messages API calls with code_execution and tools Includes evidence for Anthropic API troubleshooting demand.

Source-backed Last updated May 22, 2026 1 source Needs local verification

Category: Anthropic API
Error signature: RemoteProtocolError — Streaming /v1/messages drops mid-stream during long code_execution + skills runs, losing partial responses
Quick fix: Compare the failing environment with a known working setup, then change one configuration value at a time.
Updated: May 22, 2026
Verification status: Source-backed
Evidence: 1 public source URL

Before you change production

This page includes public source URLs in the imported troubleshooting record. Compare those references with your version and environment before applying changes.

Reproduce the smallest failing action and save non-secret logs before changing configuration.
Check versions for Anthropic API, related SDKs, package managers, CI runners, and hosting providers.
Change one setting or dependency at a time, then rerun the same failing command or request.
Avoid destructive commands, credential rotation, billing changes, or security relaxations without a rollback plan.

What this error means

RemoteProtocolError — Streaming /v1/messages drops mid-stream during long code_execution + skills runs, losing partial responses is a Anthropic API failure pattern reported for developers trying to fix intermittent streaming disconnections (remoteprotocolerror) on long-running /v1/messages api calls with code_execution and tools. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

GitHub Issue #1470 opened Apr 29, 2026 by @ypang-anytimeai on anthropics/anthropic-sdk-python. Long-running streaming sessions with code_execution skill consistently drop with WebSocket-level protocol errors. Affects production AI agent pipelines running multi-step reasoning. 3 weeks ago still open. Not in covered-errors.md.

Common causes

GitHub Issue #1470 opened Apr 29, 2026 by @ypang-anytimeai on anthropics/anthropic-sdk-python. Long-running streaming sessions with code_execution skill consistently drop with WebSocket-level protocol errors. Affects production AI agent pipelines running multi-step reasoning. 3 weeks ago still open. Not in covered-errors.md.

Quick fixes

Confirm the exact error signature matches RemoteProtocolError — Streaming /v1/messages drops mid-stream during long code_execution + skills runs, losing partial responses.
Check the Anthropic API account, local tool state, and provider configuration involved in the failing workflow.
Compare the failing environment with a known working setup, then change one configuration value at a time.

Platform/tool-specific checks

Verify the command, editor, extension, or API client that produced the error.
Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
Avoid deleting credentials, local model data, or project settings until the failing scope is clear.

Step-by-step troubleshooting

Capture the exact error message and the command, editor action, or request that triggered it.
Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
Review the source evidence below and compare it with your environment.
Apply one change at a time and rerun the smallest failing action.
Keep the working fix documented for the team or deployment environment.

How to prevent it

Keep provider/tool configuration documented.
Record non-secret diagnostics such as tool version, provider name, model name, and command path.
Add a lightweight check before CI or production workflows depend on the tool.

Diagnostic flow for this page

Match RemoteProtocolError — Streaming /v1/messages drops mid-stream during long code_execution + skills runs, losing partial responses exactly before applying the quick fix.
Compare the failing environment with Anthropic API versions, account scope, provider settings, and deployment context.
Check the listed common causes in order, starting with the cause that best matches your logs.
Use the evidence status below to decide whether to confirm against public sources or official documentation.
Apply one reversible change, rerun the smallest failing action, and keep rollback notes.

FAQ

What does RemoteProtocolError — Streaming /v1/messages drops mid-stream during long code_execution + skills runs, losing partial responses mean in Anthropic API?

RemoteProtocolError — Streaming /v1/messages drops mid-stream during long code_execution + skills runs, losing partial responses indicates the workflow described by "Streaming /v1/messages Drops Mid-Stream With RemoteProtocolError on Long Runs" failed in a Anthropic API context. Start by confirming the exact signature and the component that emitted it.

What should I check first for RemoteProtocolError — Streaming /v1/messages drops mid-stream during long code_execution + skills runs, losing partial responses?

Check whether this cause matches your environment: GitHub Issue #1470 opened Apr 29, 2026 by @ypang-anytimeai on anthropics/anthropic-sdk-python. Long-running streaming sessions with code_execution skill consistently drop with WebSocket-level protocol errors. Affects production AI agent pipelines running multi-step reasoning. 3 weeks ago still open. Not in covered-errors.md.

Is the RemoteProtocolError — Streaming /v1/messages drops mid-stream during long code_execution + skills runs, losing partial responses guidance source-backed?

The "Streaming /v1/messages Drops Mid-Stream With RemoteProtocolError on Long Runs" page is labeled source-backed. It has 1 public source URL from github.com, so use that evidence status when deciding how much additional verification you need.

When should I avoid the quick fix for RemoteProtocolError — Streaming /v1/messages drops mid-stream during long code_execution + skills runs, losing partial responses?

For "Streaming /v1/messages Drops Mid-Stream With RemoteProtocolError on Long Runs", avoid applying "Compare the failing environment with a known working setup, then change one configuration value at a time." when the error text differs, the affected version or provider is different, or the change would touch credentials, billing, DNS, production deploy settings, or irreversible data.

What should I collect before debugging RemoteProtocolError — Streaming /v1/messages drops mid-stream during long code_execution + skills runs, losing partial responses?

For "Streaming /v1/messages Drops Mid-Stream With RemoteProtocolError on Long Runs", collect the failing Anthropic API command or request, non-secret configuration, versions, timestamps, request IDs when available, and the smallest reproduction that still triggers the signature.