66 pages for onerror.
Titles and paths first, then pages whose text carries it. Each row opens that page as this site last read it.
PDF Processing
Claude Developer Platform · in the page
agents-and-tools/agent-skills/best-practices
…") as f: f.write("") return "" except PermissionError: # Provide alternative instead of failing print(f"Cannot access {path}, using default") return ""…
handle-tool-calls
Claude Developer Platform · in the page
agents-and-tools/tool-use/handle-tool-calls
…e_id": "toolu_01A09q90qw90lq917835lq9", "content": "ConnectionError: the weather service API is not available (HTTP 500)", "is_error": true } ] } ``` Cla…
Beta
Claude Developer Platform · in the page
api/beta
…ernal server error ### Beta Authentication Error - `BetaAuthenticationError object` - `type: "authentication_error"` default: authentication_error - `message: string` default: Authen…
Deployments
Claude Developer Platform · in the page
api/beta/deployments
…`type: "error"` - `error: BetaManagedAgentsDeploymentPausedReasonError` The failed run's error. - `BetaManagedAgentsEnvironmentArchivedDeploymentPausedReasonError object`…
Archive Deployment
Claude Developer Platform · in the page
api/beta/deployments/archive
…`type: "error"` - `error: BetaManagedAgentsDeploymentPausedReasonError` The failed run's error. - `BetaManagedAgentsEnvironmentArchivedDeploymentPausedReasonError object`…
Create Deployment
Claude Developer Platform · in the page
api/beta/deployments/create
…`type: "error"` - `error: BetaManagedAgentsDeploymentPausedReasonError` The failed run's error. - `BetaManagedAgentsEnvironmentArchivedDeploymentPausedReasonError object`…
List Deployments
Claude Developer Platform · in the page
api/beta/deployments/list
…`type: "error"` - `error: BetaManagedAgentsDeploymentPausedReasonError` The failed run's error. - `BetaManagedAgentsEnvironmentArchivedDeploymentPausedReasonError object`…
Pause Deployment
Claude Developer Platform · in the page
api/beta/deployments/pause
…`type: "error"` - `error: BetaManagedAgentsDeploymentPausedReasonError` The failed run's error. - `BetaManagedAgentsEnvironmentArchivedDeploymentPausedReasonError object`…
Get Deployment
Claude Developer Platform · in the page
api/beta/deployments/retrieve
…`type: "error"` - `error: BetaManagedAgentsDeploymentPausedReasonError` The failed run's error. - `BetaManagedAgentsEnvironmentArchivedDeploymentPausedReasonError object`…
Unpause Deployment
Claude Developer Platform · in the page
api/beta/deployments/unpause
…`type: "error"` - `error: BetaManagedAgentsDeploymentPausedReasonError` The failed run's error. - `BetaManagedAgentsEnvironmentArchivedDeploymentPausedReasonError object`…
Update Deployment
Claude Developer Platform · in the page
api/beta/deployments/update
…`type: "error"` - `error: BetaManagedAgentsDeploymentPausedReasonError` The failed run's error. - `BetaManagedAgentsEnvironmentArchivedDeploymentPausedReasonError object`…
Dreams
Claude Developer Platform · in the page
api/beta/dreams
…or - `BetaDreamingError = BetaInvalidRequestError or BetaAuthenticationError or BetaBillingError or 7 more` - `BetaInvalidRequestError object` - `type: "invalid_request_error"` default…
Memories
Claude Developer Platform · in the page
api/beta/memory_stores/memories
…`BetaManagedAgentsError = BetaInvalidRequestError or BetaAuthenticationError or BetaBillingError or 9 more` - `BetaInvalidRequestError object` - `type: "invalid_request_error"` default…
Retrieve Message Batch results
Claude Developer Platform · in the page
api/beta/messages/batches/results
…default: Invalid request - `BetaAuthenticationError object` - `type: "authentication_error"` default: authentication_error - `message…
Events
Claude Developer Platform · in the page
api/beta/sessions/events
…n was processed. format: date-time - `BetaManagedAgentsSessionErrorEvent object` An error event indicating a problem occurred during session execution. - `type: "session.error"`…
List Events
Claude Developer Platform · in the page
api/beta/sessions/events/list
…n was processed. format: date-time - `BetaManagedAgentsSessionErrorEvent object` An error event indicating a problem occurred during session execution. - `type: "session.error"`…
Stream Events
Claude Developer Platform · in the page
api/beta/sessions/events/stream
…n was processed. format: date-time - `BetaManagedAgentsSessionErrorEvent object` An error event indicating a problem occurred during session execution. - `type: "session.error"`…
Threads
Claude Developer Platform · in the page
api/beta/sessions/threads
…n was processed. format: date-time - `BetaManagedAgentsSessionErrorEvent object` An error event indicating a problem occurred during session execution. - `type: "session.error"`…
Events
Claude Developer Platform · in the page
api/beta/sessions/threads/events
…n was processed. format: date-time - `BetaManagedAgentsSessionErrorEvent object` An error event indicating a problem occurred during session execution. - `type: "session.error"`…
List Session Thread Events
Claude Developer Platform · in the page
api/beta/sessions/threads/events/list
…n was processed. format: date-time - `BetaManagedAgentsSessionErrorEvent object` An error event indicating a problem occurred during session execution. - `type: "session.error"`…
Stream Session Thread Events
Claude Developer Platform · in the page
api/beta/sessions/threads/events/stream
…n was processed. format: date-time - `BetaManagedAgentsSessionErrorEvent object` An error event indicating a problem occurred during session execution. - `type: "session.error"`…
Batches
Claude Developer Platform · in the page
api/messages/batches
…ng` default: Invalid request - `AuthenticationError object` - `type: "authentication_error"` default: authentication_error - `message…
Retrieve Message Batch results
Claude Developer Platform · in the page
api/messages/batches/results
…ng` default: Invalid request - `AuthenticationError object` - `type: "authentication_error"` default: authentication_error - `message…
fast-mode
Claude Developer Platform · in the page
build-with-claude/fast-mode
…( anthropic.APIStatusError, anthropic.APIConnectionError, ) as error: if isinstance(error, anthropic.APIStatusError) and error.status_code < 500: rai…
API usage primer for Claude
Claude Developer Platform · in the page
claude_api_primer
…l_use_id": "toolu_01A09q90qw90lq917835lq9", "content": "ConnectionError: the weather service API is not available (HTTP 500)", "is_error": true } ] } ``` ### Invalid tool name If C…
For Amazon Bedrock support
Claude Developer Platform · in the page
cli-sdks-libraries/sdks/python
…], model="claude-opus-5-5", ) except anthropic.APIConnectionError as e: print("The server could not be reached") print(e.__cause__) # an underlying Exception, likely raised within…
Automatically handles tool execution loop
Claude Developer Platform · in the page
cli-sdks-libraries/sdks/ruby
…opic::Model::CLAUDE_OPUS_5_5 ) rescue Anthropic::Errors::APIConnectionError => e puts("The server could not be reached") puts(e.cause) # an underlying Exception, likely raised within `net/http`…
typescript
Claude Developer Platform · in the page
cli-sdks-libraries/sdks/typescript
…0 | `BadRequestError` | | 401 | `AuthenticationError` | | 403 | `PermissionDeniedError` | | 404 | `NotFoundError` | | 409 | `Conflic…
events-and-streaming
Claude Developer Platform · in the page
managed-agents/events-and-streaming
…ak; } else if (streamEvent.Value is BetaManagedAgentsSessionErrorEvent error) { Console.WriteLine($"\n[Error: {error.Error?.Message ?? "unknown"}]"); break;…
spawn.sh: called once per claimed work item
Claude Developer Platform · in the page
managed-agents/self-hosted-sandboxes
…ers=headers) except standardwebhooks.WebhookVerificationError: return {"error": "signature verification failed"}, 401 if event.data.type != "session…
self-hosted-sandboxes-workers
Claude Developer Platform · in the page
managed-agents/self-hosted-sandboxes-workers
…headers=headers) except standardwebhooks.WebhookVerificationError: return {"error": "signature verification failed"}, 401 if event.data.type != "session.status_…
Hosting the Agent SDK
Claude Code CLI · in the page
agent-sdk/hosting
…o start Claude Code](/docs/en/agent-sdk/troubleshooting.md#cliconnectionerror-failed-to-start-claude-code). * **Claude Code process exits mid-run**: the error your application receives depends on the…
Agent SDK reference - Python
Claude Code CLI · in the page
agent-sdk/python
…not found. ```python theme={null} class CLINotFoundError(CLIConnectionError): def __init__( self, message: str = "Claude Code not found", cli_path: str | None = None ): """…
Troubleshoot the Agent SDK
Claude Code CLI · in the page
agent-sdk/troubleshooting
…ocs/en/errors.md#find-your-error) | | `CLINotFoundError`, `CLIConnectionError`, `ProcessError`, `Claude Code process exited with code N`, `Claude Code returned an error result`, `structured_output` is…
Deploy Claude apps gateway on AWS
Claude Code CLI · in the page
claude-apps-gateway-on-aws
…atalog already does this | | ECS task stops with `ResourceInitializationError` before the gateway logs anything | The execution role can't read the Secrets Manager secrets, or the private subnets have…
Extend Claude with skills
Claude Code CLI · in the page
skills
…result["size"] += child["size"] except PermissionError: pass return result def generate_html(data: dict, stats: dict, output: Path) -> None: ext_sizes = stats["…
Build an MCP client
Model Context Protocol · in the page
docs/2024-11-05/develop/build-client
…uired environment variables are set * `Anthropic::Errors::AuthenticationError`: Check your `.env` file has a valid `ANTHROPIC_API_KEY` **Rust** [You can find the complete code for this tutorial here…
Build an MCP client
Model Context Protocol · in the page
docs/2025-03-26/develop/build-client
…uired environment variables are set * `Anthropic::Errors::AuthenticationError`: Check your `.env` file has a valid `ANTHROPIC_API_KEY` **Rust** [You can find the complete code for this tutorial here…
Build an MCP client
Model Context Protocol · in the page
docs/2025-06-18/develop/build-client
…uired environment variables are set * `Anthropic::Errors::AuthenticationError`: Check your `.env` file has a valid `ANTHROPIC_API_KEY` **Rust** [You can find the complete code for this tutorial here…
Build an MCP client
Model Context Protocol · in the page
docs/2025-11-25/develop/build-client
…uired environment variables are set * `Anthropic::Errors::AuthenticationError`: Check your `.env` file has a valid `ANTHROPIC_API_KEY` **Rust** [You can find the complete code for this tutorial here…
Build an MCP client
Model Context Protocol · in the page
docs/2026-07-28/develop/build-client
…uired environment variables are set * `Anthropic::Errors::AuthenticationError`: Check your `.env` file has a valid `ANTHROPIC_API_KEY` **Rust** [You can find the complete code for this tutorial here…
Build an MCP server
Model Context Protocol · in the page
docs/2026-07-28/develop/build-server
…over stdio: ```typescript theme={null} serveStdio(createServer, { onerror: (error) => console.error("Weather MCP Server error:", error), }); console.error("Weather MCP Server running on stdio"); `…
Architecture overview
Model Context Protocol · in the page
docs/2026-07-28/learn/architecture
…sted version, it rejects the request with an `UnsupportedProtocolVersionError` listing the versions it does support, and the client retries with a mutually supported version. 2. **Capability Discover…
Versioning
Model Context Protocol · in the page
docs/2026-07-28/learn/versioning
…the requested version, it responds with an [`UnsupportedProtocolVersionError`](/specification/2026-07-28/basic/versioning#protocol-version-negotiation) listing the versions it does support. The clien…
Debugging
Model Context Protocol · in the page
docs/2026-07-28/tools/debugging
…protocol versions the server supports. An `UnsupportedProtocolVersionError` (`-32022`) lists the server's supported versions in its `data` field 5. Check the [per-request `_meta` fields](/spe…
Understanding Authorization in MCP
Model Context Protocol · in the page
docs/2026-07-28/tutorials/security/authorization
…that list straight in raises a pydantic # ValidationError that the broad `except` below turns into a # silent 401. We already confirmed this server's resource i…
Build an MCP client
Model Context Protocol · in the page
docs/draft/develop/build-client
…uired environment variables are set * `Anthropic::Errors::AuthenticationError`: Check your `.env` file has a valid `ANTHROPIC_API_KEY` **Rust** [You can find the complete code for this tutorial here…
Build an MCP server
Model Context Protocol · in the page
docs/draft/develop/build-server
…over stdio: ```typescript theme={null} serveStdio(createServer, { onerror: (error) => console.error("Weather MCP Server error:", error), }); console.error("Weather MCP Server running on stdio"); `…
Architecture overview
Model Context Protocol · in the page
docs/draft/learn/architecture
…sted version, it rejects the request with an `UnsupportedProtocolVersionError` listing the versions it does support, and the client retries with a mutually supported version. 2. **Capability Discover…
Versioning
Model Context Protocol · in the page
docs/draft/learn/versioning
…the requested version, it responds with an [`UnsupportedProtocolVersionError`](/specification/draft/basic/versioning#protocol-version-negotiation) listing the versions it does support. The client can…