Anthropic API / Anthropic API

Managed Agents: vault_ids not inherited by subagents dispatched via agent_toolset — MCP OAuth calls fail

Fix anthropic managed agents subagent dispatch failing with MCP OAuth auth errors due to missing vault credential inheritance Includes evidence for Anthropic API troubleshooting demand.

Source-backed Last updated May 18, 2026 1 source Needs local verification

Category: Anthropic API
Error signature: vault_ids not inherited by subagents dispatched via agent_toolset — MCP OAuth calls fail
Quick fix: Verify the account session, API key, provider settings, and environment where the failing tool is running.
Updated: May 18, 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

vault_ids not inherited by subagents dispatched via agent_toolset — MCP OAuth calls fail is a Anthropic API failure pattern reported for developers trying to fix anthropic managed agents subagent dispatch failing with mcp oauth auth errors due to missing vault credential inheritance. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

GitHub issue #1562 in anthropics/anthropic-sdk-python (opened May 18, 2026). Coordinator agent using sessions.create with vault_ids for MCP OAuth tools cannot pass credentials to subagents spawned via agent_toolset_20260401. All subagent MCP tool calls result in is_error=True auth failures. This blocks multi-agent patterns requiring OAuth-backed MCP servers.

Common causes

GitHub issue #1562 in anthropics/anthropic-sdk-python (opened May 18, 2026). Coordinator agent using sessions.create with vault_ids for MCP OAuth tools cannot pass credentials to subagents spawned via agent_toolset_20260401. All subagent MCP tool calls result in is_error=True auth failures. This blocks multi-agent patterns requiring OAuth-backed MCP servers.

Quick fixes

Confirm the exact error signature matches vault_ids not inherited by subagents dispatched via agent_toolset — MCP OAuth calls fail.
Check the Anthropic API 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 vault_ids not inherited by subagents dispatched via agent_toolset — MCP OAuth calls fail 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 vault_ids not inherited by subagents dispatched via agent_toolset — MCP OAuth calls fail mean in Anthropic API?

vault_ids not inherited by subagents dispatched via agent_toolset — MCP OAuth calls fail indicates the workflow described by "Managed Agents: vault_ids not inherited by subagents dispatched via agent_toolset — MCP OAuth calls fail" failed in a Anthropic API context. Start by confirming the exact signature and the component that emitted it.

What should I check first for vault_ids not inherited by subagents dispatched via agent_toolset — MCP OAuth calls fail?

Check whether this cause matches your environment: GitHub issue #1562 in anthropics/anthropic-sdk-python (opened May 18, 2026). Coordinator agent using sessions.create with vault_ids for MCP OAuth tools cannot pass credentials to subagents spawned via agent_toolset_20260401. All subagent MCP tool calls result in is_error=True auth failures. This blocks multi-agent patterns requiring OAuth-backed MCP servers.

Is the vault_ids not inherited by subagents dispatched via agent_toolset — MCP OAuth calls fail guidance source-backed?

The "Managed Agents: vault_ids not inherited by subagents dispatched via agent_toolset — MCP OAuth calls fail" 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 vault_ids not inherited by subagents dispatched via agent_toolset — MCP OAuth calls fail?

For "Managed Agents: vault_ids not inherited by subagents dispatched via agent_toolset — MCP OAuth calls fail", 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 vault_ids not inherited by subagents dispatched via agent_toolset — MCP OAuth calls fail?

For "Managed Agents: vault_ids not inherited by subagents dispatched via agent_toolset — MCP OAuth calls fail", 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.