Anthropic API / Anthropic API

Anthropic Managed Agents: vault_ids not inherited by subagent MCP OAuth calls

Fix subagent dispatch pattern where coordinator agent's vault-based OAuth credentials cannot reach subagent's MCP tool execution context Includes evidence for Anthropic API troubleshooting demand.

Source-backed Last updated May 23, 2026 1 source Needs local verification

Category: Anthropic API
Error signature: MCP OAuth calls fail in subagents — vault_ids parameter exists only on sessions.create, no mechanism to pass credentials when dispatching subagents via agent_toolset
Quick fix: Verify the account session, API key, provider settings, and environment where the failing tool is running.
Updated: May 23, 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

MCP OAuth calls fail in subagents — vault_ids parameter exists only on sessions.create, no mechanism to pass credentials when dispatching subagents via agent_toolset is a Anthropic API failure pattern reported for developers trying to fix subagent dispatch pattern where coordinator agent's vault-based oauth credentials cannot reach subagent's mcp tool execution context. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

Issue #1562 on anthropics/anthropic-sdk-python (open, 1 comment, created 2026-05-18). Coordinator agents with vault_ids can call MCP tools directly but any subagent dispatched via agent_toolset cannot inherit those credentials. Makes vault-backed MCP tools completely unusable in multi-agent patterns. Strong B2B enterprise use case.

Common causes

Issue #1562 on anthropics/anthropic-sdk-python (open, 1 comment, created 2026-05-18). Coordinator agents with vault_ids can call MCP tools directly but any subagent dispatched via agent_toolset cannot inherit those credentials. Makes vault-backed MCP tools completely unusable in multi-agent patterns. Strong B2B enterprise use case.

Quick fixes

Confirm the exact error signature matches MCP OAuth calls fail in subagents — vault_ids parameter exists only on sessions.create, no mechanism to pass credentials when dispatching subagents via agent_toolset.
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 MCP OAuth calls fail in subagents — vault_ids parameter exists only on sessions.create, no mechanism to pass credentials when dispatching subagents via agent_toolset 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 MCP OAuth calls fail in subagents — vault_ids parameter exists only on sessions.create, no mechanism to pass credentials when dispatching subagents via agent_toolset mean in Anthropic API?

MCP OAuth calls fail in subagents — vault_ids parameter exists only on sessions.create, no mechanism to pass credentials when dispatching subagents via agent_toolset indicates the workflow described by "Anthropic Managed Agents: vault_ids not inherited by subagent MCP OAuth calls" failed in a Anthropic API context. Start by confirming the exact signature and the component that emitted it.

What should I check first for MCP OAuth calls fail in subagents — vault_ids parameter exists only on sessions.create, no mechanism to pass credentials when dispatching subagents via agent_toolset?

Check whether this cause matches your environment: Issue #1562 on anthropics/anthropic-sdk-python (open, 1 comment, created 2026-05-18). Coordinator agents with vault_ids can call MCP tools directly but any subagent dispatched via agent_toolset cannot inherit those credentials. Makes vault-backed MCP tools completely unusable in multi-agent patterns. Strong B2B enterprise use case.

Is the MCP OAuth calls fail in subagents — vault_ids parameter exists only on sessions.create, no mechanism to pass credentials when dispatching subagents via agent_toolset guidance source-backed?

The "Anthropic Managed Agents: vault_ids not inherited by subagent MCP OAuth calls" 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 MCP OAuth calls fail in subagents — vault_ids parameter exists only on sessions.create, no mechanism to pass credentials when dispatching subagents via agent_toolset?

For "Anthropic Managed Agents: vault_ids not inherited by subagent MCP OAuth calls", 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 MCP OAuth calls fail in subagents — vault_ids parameter exists only on sessions.create, no mechanism to pass credentials when dispatching subagents via agent_toolset?

For "Anthropic Managed Agents: vault_ids not inherited by subagent MCP OAuth calls", 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.