Claude Code / AI Coding Tools

OAuth completes but Bearer token never sent to MCP server — Claude Code needs re-authentication

Fix Claude Code MCP OAuth flow where token acquisition appears successful but the server continues requesting authentication, requiring manual restart or re-login Includes evidence for Claude Code troubleshooting demand.

Source-backed Last updated June 10, 2026 3 sources Needs local verification

Category: AI Coding Tools
Error signature: Claude Code OAuth authentication completes but MCP server stays in 'Needs authentication' state; Bearer token never sent to downstream server
Quick fix: Verify the account session, API key, provider settings, and environment where the failing tool is running.
Updated: June 10, 2026
Verification status: Source-backed
Evidence: 3 public source URLs

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 Claude Code, 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

Claude Code OAuth authentication completes but MCP server stays in 'Needs authentication' state; Bearer token never sent to downstream server is a Claude Code failure pattern reported for developers trying to fix claude code mcp oauth flow where token acquisition appears successful but the server continues requesting authentication, requiring manual restart or re-login. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

Issues #46140, #60260, #65408 on anthropics/claude-code report OAuth flow bugs: completion succeeds but token is not honored, causing persistent auth loops. Affects paid users relying on Claude Code in production development workflows. AI coding tool broken = significant commercial value boost. Category mapping: Claude Code specific auth/MCP bug → AI Coding Tools.

Common causes

Issues #46140, #60260, #65408 on anthropics/claude-code report OAuth flow bugs: completion succeeds but token is not honored, causing persistent auth loops. Affects paid users relying on Claude Code in production development workflows. AI coding tool broken = significant commercial value boost. Category mapping: Claude Code specific auth/MCP bug → AI Coding Tools.

Quick fixes

Confirm the exact error signature matches Claude Code OAuth authentication completes but MCP server stays in 'Needs authentication' state; Bearer token never sent to downstream server.
Check the Claude Code account, local tool state, and provider configuration involved in the failing workflow.
Verify the account session, API key, provider settings, and environment where the failing tool is running.

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 Claude Code OAuth authentication completes but MCP server stays in 'Needs authentication' state; Bearer token never sent to downstream server exactly before applying the quick fix.
Compare the failing environment with Claude Code 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 Claude Code OAuth authentication completes but MCP server stays in 'Needs authentication' state; Bearer token never sent to downstream server mean in Claude Code?

Claude Code OAuth authentication completes but MCP server stays in 'Needs authentication' state; Bearer token never sent to downstream server indicates the workflow described by "OAuth completes but Bearer token never sent to MCP server — Claude Code needs re-authentication" failed in a AI Coding Tools context. Start by confirming the exact signature and the component that emitted it.

What should I check first for Claude Code OAuth authentication completes but MCP server stays in 'Needs authentication' state; Bearer token never sent to downstream server?

Check whether this cause matches your environment: Issues #46140, #60260, #65408 on anthropics/claude-code report OAuth flow bugs: completion succeeds but token is not honored, causing persistent auth loops. Affects paid users relying on Claude Code in production development workflows. AI coding tool broken = significant commercial value boost. Category mapping: Claude Code specific auth/MCP bug → AI Coding Tools.

Is the Claude Code OAuth authentication completes but MCP server stays in 'Needs authentication' state; Bearer token never sent to downstream server guidance source-backed?

The "OAuth completes but Bearer token never sent to MCP server — Claude Code needs re-authentication" page is labeled source-backed. It has 3 public source URLs from github.com, so use that evidence status when deciding how much additional verification you need.

When should I avoid the quick fix for Claude Code OAuth authentication completes but MCP server stays in 'Needs authentication' state; Bearer token never sent to downstream server?

For "OAuth completes but Bearer token never sent to MCP server — Claude Code needs re-authentication", avoid applying "Verify the account session, API key, provider settings, and environment where the failing tool is running." 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 Claude Code OAuth authentication completes but MCP server stays in 'Needs authentication' state; Bearer token never sent to downstream server?

For "OAuth completes but Bearer token never sent to MCP server — Claude Code needs re-authentication", collect the failing Claude Code command or request, non-secret configuration, versions, timestamps, request IDs when available, and the smallest reproduction that still triggers the signature.