* fix: bound MCP server bring-up timeouts and exclude externalized tool outputs from delivery verification
Two related robustness fixes:
1. MCP server bring-up was unbounded. tool_call_timeout only covered
session.call_tool(); tool discovery (subprocess spawn + initialize +
tools/list) and persistent stdio session initialization could hang
forever, blocking agent construction (and on the Gateway event loop,
the whole process). Add a per-server session_init_timeout
(default DEFAULT_MCP_SESSION_INIT_TIMEOUT = 60s, null disables) that
bounds both discovery and pooled-session initialization. The session
pool's existing cancellation handling tears down a session stuck
mid-creation in its own task.
2. ToolOutputBudgetMiddleware externalizes oversized tool outputs into
outputs/.tool-results/ (configurable tool_output.storage_subdir). The
workspace-change scanner and run delivery verification counted those
files as produced artifacts, so any run that externalized a tool output
without also presenting a real artifact failed with
"Artifact delivery incomplete". Exclude TOOL_RESULTS_DIRNAME via a
shared constant (mirroring BROWSER_FRAMES_DIRNAME) and thread the
configured storage_subdir through snapshot capture so both
workspace-changes events and delivery verification stay clean.
* review: enforce single-segment tool_output.storage_subdir; document discovery-timeout cleanup
Address review feedback:
1. A custom tool_output.storage_subdir with a path separator (e.g.
cache/tool-results) silently no-oped the workspace-scanner exclusion:
os.walk yields one-segment dirnames, so a nested value never matched and
its files were counted as produced artifacts again. ToolOutputConfig now
validates storage_subdir as a single directory name (rejects separators,
.., absolute, empty) with tests, so the exclusion is always sound.
2. The discovery-timeout path now documents why cancellation is safe, mirroring
the session-init note: discovery runs inside the adapter's nested async
context managers, and stdio_client's finally terminates the process tree
(SIGTERM->SIGKILL on POSIX, process-tree on Windows), so a timed-out npx
subprocess and its children are reaped rather than accumulating.
* review: log session-init timeouts and align API response model default with runtime config
Address second-round review feedback:
1. A session-init timeout raised TimeoutError without any log, unlike the
discovery timeout which logs a WARNING. Wrap the bounded get_session in a
try/except that logs the timeout (server name + seconds) and re-raises, so
operators can diagnose tool-call failures caused by hung MCP sessions.
2. McpServerConfigResponse.session_init_timeout defaulted to None while
McpServerConfig defaults to 60s: a server created via PUT /api/mcp/config
without the field was persisted with null (no timeout) while the same
server created in the config file got 60s. Align the response-model default
to DEFAULT_MCP_SESSION_INIT_TIMEOUT so API-created and file-created servers
behave the same; an explicit null still opts out.
* review: narrow the discovery-timeout handler to the bounded wait_for path
The except TimeoutError clause covered both the bounded wait_for branch and
the bare discovery branch. With session_init_timeout opted out (None), a
TimeoutError raised by discovery itself would hit the %.1f format with None:
logging raises TypeError internally, the WARNING is silently dropped, and a
--- Logging error --- traceback goes to stderr.
Narrow the handler to wrap only the wait_for call, where the branch condition
guarantees the timeout value is not None. A discovery-internal TimeoutError on
the opted-out path now falls through to the generic failure handler and is
reported as 'tool discovery failed' with exc_info. Covered by a regression
test that asserts the skip is reported without any broken format.
* feat(mcp): add per-server tool_call_timeout for MCP tool calls
Add a configurable timeout for individual MCP tool calls to prevent
agent runs from blocking indefinitely when an MCP server becomes
unresponsive (e.g., rate-limited HTTP API, hung subprocess).
Uses the MCP SDK's built-in read_timeout_seconds parameter on
ClientSession.call_tool, which handles the timeout within the
session's own task — avoiding cross-task cancellation issues with
the session pool (ref #3379, #3203).
Config field is named tool_call_timeout (not timeout) to avoid
collision with langchain-mcp-adapters' existing timeout field on
HTTP/SSE connections.
Closes#3840
* fix(mcp): read tool_call_timeout from McpServerConfig, not connection dict
The previous implementation put tool_call_timeout into the connection dict
returned by build_server_params, which langchain's create_session then
passed to _create_stdio_session(), causing TypeError. Now reads the timeout
directly from ExtensionsConfig.mcp_servers where the wrapper is built,
keeping it out of the connection dict entirely.
Fixes P1 bug from review on #3843.
* test(mcp): regression test for tool_call_timeout not leaking into connection dict
Adds two tests:
- test_build_server_params_excludes_tool_call_timeout: verifies the connection
dict returned by build_server_params() does NOT contain tool_call_timeout
- test_stdio_tool_call_timeout_does_not_raise_typeerror: end-to-end test that
get_mcp_tools() with a stdio server having tool_call_timeout configured loads
tools without TypeError from _create_stdio_session()
Regression for PR #3843 P1 bug.
* fix(mcp): only pass read_timeout_seconds when tool_call_timeout is set
When tool_call_timeout is None, don't pass read_timeout_seconds=None to
session.call_tool(). This avoids breaking existing tests that assert on
exact call_tool arguments without the extra kwarg.
* docs(mcp): clarify stdio tool timeout
* feat(mcp): support custom tool interceptors via extensions_config.json
Add a generic extension point for registering custom MCP tool
interceptors through `extensions_config.json`. This allows downstream
projects to inject per-request header manipulation, auth context
propagation, or other cross-cutting concerns without modifying
DeerFlow source code.
Interceptors are declared as Python callable paths in a new
`mcpInterceptors` array field and loaded via the existing
`resolve_variable` reflection mechanism:
```json
{
"mcpInterceptors": [
"my_package.mcp.auth:build_auth_interceptor"
]
}
```
Each entry must resolve to a no-arg builder function that returns an
async interceptor compatible with `MultiServerMCPClient`'s
`tool_interceptors` interface.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
* test(mcp): add unit tests for custom tool interceptors
Cover all branches of the mcpInterceptors loading logic:
- valid interceptor loaded and appended to tool_interceptors
- multiple interceptors loaded in declaration order
- builder returning None is skipped
- resolve_variable ImportError logged and skipped
- builder raising exception logged and skipped
- absent mcpInterceptors field is safe (no-op)
- custom interceptors coexist with OAuth interceptor
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
* Potential fix for pull request finding
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
* fix(mcp): validate mcpInterceptors type and fix lint warnings
Address review feedback:
1. Validate mcpInterceptors config value before iterating:
- Accept a single string and normalize to [string]
- Ignore None silently
- Log warning and skip for non-list/non-string types
2. Fix ruff F841 lint errors in tests:
- Rename _make_mock_env to _make_patches, embed mock_client
- Remove unused `as mock_cls` bindings where not needed
- Extract _get_interceptors() helper to reduce repetition
3. Add two new test cases for type validation:
- test_mcp_interceptors_single_string_is_normalized
- test_mcp_interceptors_invalid_type_logs_warning
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
* fix(mcp): validate interceptor return type and fix import mock path
Address review feedback:
1. Validate builder return type with callable() check:
- callable interceptor → append to tool_interceptors
- None → silently skip (builder opted out)
- non-callable → log warning with type name and skip
2. Fix test mock path: resolve_variable is a top-level import in
tools.py, so mock deerflow.mcp.tools.resolve_variable instead of
deerflow.reflection.resolve_variable to correctly intercept calls.
3. Add test_custom_interceptor_non_callable_return_logs_warning to
cover the new non-callable validation branch.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
* docs(mcp): add mcpInterceptors example and documentation
- Add mcpInterceptors field to extensions_config.example.json
- Add "Custom Tool Interceptors" section to MCP_SERVER.md with
configuration format, example interceptor code, and edge case
behavior notes
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---------
Co-authored-by: IECspace <IECspace@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Co-authored-by: Willem Jiang <willem.jiang@gmail.com>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
* Refactor sandbox state management and improve Docker integration
- Removed FileSandboxStateStore and SandboxStateStore classes for a cleaner architecture.
- Enhanced LocalContainerBackend to handle port allocation retries and introduced environment variable support for sandbox host configuration.
- Updated Paths class to include host_base_dir for Docker volume mounts and ensured proper permissions for sandbox directories.
- Modified ExtensionsConfig to improve error handling when loading configuration files and adjusted environment variable resolution.
- Updated sandbox configuration to include a replicas option for managing concurrent sandbox containers.
- Improved logging and context management in SandboxMiddleware for better sandbox lifecycle handling.
- Enhanced network port allocation logic to bind to 0.0.0.0 for compatibility with Docker.
- Updated Docker Compose files to ensure proper volume management and environment variable configuration.
- Created scripts to ensure necessary configuration files are present before starting services.
- Cleaned up unused MCP server configurations in extensions_config.example.json.
* Address Copilot review suggestions from PR #1068 (#9)
---------
Co-authored-by: Copilot <198982749+Copilot@users.noreply.github.com>
add oauth schema to MCP server config (extensions_config.json)
support client_credentials and refresh_token grants
implement token manager with caching and pre-expiry refresh
inject OAuth Authorization header for MCP tool discovery and tool calls
extend MCP gateway config models to read/write OAuth settings
update docs and examples for OAuth configuration
add unit tests for token fetch/cache and header injection
- Add type, url, and headers fields to MCP server config
- Update MCP client to handle stdio, sse, and http transports
- Add todos field to ThreadState
- Add Deerflow branding requirement to frontend-design skill
- Update extensions_config.example.json with SSE/HTTP examples
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
