Resolves
https://linear.app/arcadedev/issue/TOO-788/mypy-failures-are-silently-dropped-during-arcade-mcp-ci
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> **Low Risk**
> Low risk: primarily CI/Makefile behavior and type-annotation tweaks;
functional logic is unchanged aside from stricter failure propagation in
`make check`.
>
> **Overview**
> **Stops CI from silently ignoring mypy failures.** The `make check`
target now runs `mypy` across `libs/arcade*/` and exits non-zero if any
package fails, reporting the failed libs.
>
> Separately tightens typing to satisfy `mypy` (removing `type: ignore`
on OAuth helpers, adding `cast()`/`Any` annotations for JSON response
shapes and subprocess kwargs, and handling non-`str` `server_address`
hosts), and bumps patch versions for `arcade-mcp` and
`arcade-mcp-server`.
>
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
e79575b13a2d03adf3548104a0064c643f1e21b1. Bugbot is set up for automated
code reviews on this repo. Configure
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<!-- /CURSOR_SUMMARY -->
## Summary
Adds two strictly opt-in env vars that let toolkit developers see
`developer_message` / `stacktrace` content *in* the agent-facing error
message while debugging. Off by default; activation requires a specific
acknowledgement string, not a boolean — `true`/`1` is explicitly
rejected with a warning log.
- `ARCADE_UNSAFE_DEBUG_LEAK_DEVELOPER_MESSAGE_TO_AGENT`
- `ARCADE_UNSAFE_DEBUG_LEAK_STACKTRACE_TO_AGENT`
- Magic ack: `yes-i-accept-leaking-internals-to-the-agent`
Everything goes through a single funnel — `ToolOutputFactory.fail` /
`fail_retry` in `arcade_core/output.py` — so the behavior covers both
the MCP server path and the Arcade Worker path with no call-site
changes. A loud `logger.warning` fires once per process on activation,
and a big header comment in `output.py` tells future maintainers not to
add more flags of this shape (debug info belongs in `logger.debug`, not
in a field that gets shipped to the model and often to end users).
Bumps `arcade-core` 4.6.2 → 4.7.0. Non-breaking, additive.
## Why
Today the project does a lot of work to keep `developer_message` and
`stacktrace` off the agent's context. That's the right default, but it
makes iterating on a new toolkit painful — you end up adding temporary
logging or rebuilds just to see what blew up. This gives toolkit authors
a safe, ugly, loud-on-activation escape hatch.
## Safety design
- Two separate flags so you only leak what you need.
- Magic string (not a boolean) activates the flag. Boolean-style values
are rejected and log a pointer to `output.py`.
- First activation logs a `WARNING` identifying the flag and the risk.
- Flags documented only in `CLAUDE.md`, not in the public README.
- Top-of-file banner in `output.py` explicitly tells maintainers not to
add more flags of this shape.
## Test plan
- [x] Existing test suite passes (1154 tests —
`libs/tests/{core,tool,arcade_mcp_server}`).
- [x] End-to-end smoke test against the built `arcade_core-4.7.0` wheel,
driven through `ToolExecutor.run` (same path toolkits hit). Covered
cases:
- flags off → message unchanged
- `ARCADE_UNSAFE_..._DEVELOPER_MESSAGE_TO_AGENT=true` → flag rejected,
warning logged, message unchanged
- `ARCADE_UNSAFE_..._DEVELOPER_MESSAGE_TO_AGENT=<magic>` → `[DEBUG]
developer_message: ...` appended
- both flags with magic, `ToolRuntimeError` path → developer_message
appended (stacktrace absent because `ToolRuntimeError.stacktrace()`
returned `None`, which is existing behavior)
- stacktrace flag with magic, generic `Exception` path → full
`traceback.format_exc()` appended, activation `WARNING` visible
Made with [Cursor](https://cursor.com)
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> **Medium Risk**
> Adds an opt-in path to include `developer_message` and stacktraces in
agent-facing MCP error messages, which could leak sensitive data if
misconfigured; safeguards (magic ack string + CI/pre-commit guard)
reduce but don’t eliminate risk.
>
> **Overview**
> Adds `arcade_mcp_server/_debug_exposure.py` with two env-gated debug
flags that, only when set to a specific acknowledgement string, append
`developer_message` and/or `stacktrace` into the agent-visible MCP tool
error `message` (and logs one-shot warnings on rejection/activation).
>
> Wires this into the MCP error path in `MCPServer._handle_call_tool`,
documents the flags in `CLAUDE.md`, bumps `arcade-mcp-server` to
`1.21.0`, and adds unit + integration tests plus a pre-commit hook and
GitHub Actions workflow (`scripts/check_debug_leak_flags_off.py`) to
ensure the magic ack string can’t be committed outside a small
allowlist.
>
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
30e242c454128ec7cc62e169c2afd116be735cb5. Bugbot is set up for automated
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<!-- /CURSOR_SUMMARY -->
## Summary
- Adds `NetworkTransportError` — a new sibling to `UpstreamError` under
`ToolExecutionError` — for failures where no complete HTTP response was
received from the upstream service (timeouts, connection errors, pool
exhaustion, DNS failures, decoding issues, redirect exhaustion)
- Routes client-construction bugs (`InvalidURL`, `UnsupportedProtocol`,
`MissingSchema`, `SSLError`, `InvalidHeader`, etc.) to existing
`FatalToolError` instead of `UpstreamError`
- Adds 3 new `ErrorKind` values: `NETWORK_TRANSPORT_RUNTIME_TIMEOUT`,
`_UNREACHABLE`, `_UNMAPPED` — operationally distinct telemetry slices
matching the UpstreamError pattern
- `UpstreamError` is unchanged and reserved for real HTTP responses with
status codes
Addresses Eric's feedback on #820: the `include_status_code=False`
post-init null-out workaround is replaced by a clean class hierarchy
where `NetworkTransportError.status_code` is natively `None`.
### Changes
| File | What |
|---|---|
| `arcade-core/errors.py` | 3 new `ErrorKind` values,
`NetworkTransportError` class, `is_network_transport_error` helper |
| `arcade-tdk/providers/http/error_adapter.py` | Full rewrite of httpx +
requests exception routing with 3-way split |
| `arcade-tdk/providers/graphql/error_adapter.py` |
`TransportConnectionFailed`/`TransportProtocolError` →
`NetworkTransportError` |
| `arcade-tdk/errors.py`, `arcade-mcp-server/exceptions.py` | Re-exports
|
| `pyproject.toml` × 3 | Version bumps: core 4.7.0, tdk 3.7.0,
mcp-server 1.20.0 |
| Tests × 3 | 33 new tests, 3 updated (2659 passed, 0 failures) |
### Exception routing table
| Exception | Target | Kind | can_retry |
|---|---|---|---|
| `httpx.HTTPStatusError`, `requests.HTTPError` (with response) |
`UpstreamError` | status-derived | status-derived |
| `httpx.TimeoutException`, `requests.Timeout` | `NetworkTransportError`
| `TIMEOUT` | ✅ |
| `httpx.TransportError`, `requests.ConnectionError` |
`NetworkTransportError` | `UNREACHABLE` | ✅ |
| `httpx.DecodingError`, `TooManyRedirects`, fallback |
`NetworkTransportError` | `UNMAPPED` | varies |
| `httpx.InvalidURL`/`UnsupportedProtocol`/`LocalProtocolError`,
`requests.MissingSchema`/`SSLError`/etc. | `FatalToolError` |
`TOOL_RUNTIME_FATAL` | ❌ |
### Engine companion PR
ArcadeAI/monorepo — `feat/network-transport-error-kinds` adds the 3
`ErrorKind` constants to Go schemas + OpenAPI docs. No engine logic
changes needed (ErrorKind is a string alias, retry uses `can_retry` flag
only, telemetry auto-slices).
## Test plan
- [x] 2659 existing tests pass (0 failures)
- [x] 33 new routing + class tests added
- [x] mypy clean on arcade-core, arcade-tdk
- [ ] Verify engine telemetry dashboard auto-surfaces new
`NETWORK_TRANSPORT_*` kinds after deploy
🤖 Generated with [Claude Code](https://claude.com/claude-code)
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> **Medium Risk**
> Changes the error taxonomy and classification helpers used for
retries/telemetry, so misclassification could affect operational
behavior, but the change is additive and covered by new tests.
>
> **Overview**
> Adds a new error category for outbound request failures that never
yield a complete upstream response: `NetworkTransportError` (sibling to
`UpstreamError`) plus
`ErrorKind.NETWORK_TRANSPORT_RUNTIME_{TIMEOUT,UNREACHABLE,UNMAPPED}` and
matching `is_network_transport_error` classification helpers on both
`ToolkitError` and the wire-model `ToolCallError`.
>
> Re-exports `NetworkTransportError` from `arcade-tdk` and
`arcade-mcp-server`, bumps package versions (`arcade-core` 4.7.0,
`arcade-tdk` 3.7.0, `arcade-mcp-server` 1.20.0) and dependency minimums,
and expands `core/test_errors.py` to cover the new kind
invariants/defaults and classification behavior.
>
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
d2b89078729c6a67ba42684dc98445352238bc1d. Bugbot is set up for automated
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<!-- /CURSOR_SUMMARY -->
---------
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
## Summary
- Improve tool call error messages across 4 libraries (arcade-core,
arcade-tdk, arcade-mcp-server, arcade-serve) so agents can self-correct
and Datadog can facet on structured fields
- Guard empty error messages, enrich input validation errors with
field-level detail, fix `@tool` decorator fallback formatting, surface
`additional_prompt_content` in MCP responses, and add structured log
extras for Datadog
- Addresses the 3 worst error patterns: generic "Error in tool input
deserialization", bare `KeyError` values, and empty `FatalToolError`
messages
**Linear:** TOO-627
**Plan:** `docs/plans/2026-04-08-improve-error-messages-handoff.md`
## Tasks
- [ ] Task 1: Guard empty error messages (arcade-core)
- [ ] Task 2: Enrich input validation error messages (arcade-core)
- [ ] Task 3: Improve `@tool` decorator error fallback (arcade-tdk)
- [ ] Task 4: Fix MCP agent-facing error response (arcade-mcp-server)
- [ ] Task 5: Add structured log extras in BaseWorker (arcade-serve)
- [ ] Task 6: Add structured log extras in MCP server
(arcade-mcp-server)
## Test plan
- [ ] Each task has dedicated unit tests verifying the new behavior
- [ ] `make test` passes after all tasks
- [ ] `make check` (ruff + mypy) passes
- [ ] Verify the 3 worst error patterns now produce actionable messages
🤖 Generated with [Claude Code](https://claude.com/claude-code)
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> **Medium Risk**
> Touches cross-library error formatting and logging behavior used in
production tool execution paths; while mostly additive/guardrails, it
changes agent-visible messages and Datadog log facets, which could
impact client expectations and alerting.
>
> **Overview**
> Improves tool-call error handling across core/runtime, MCP transport,
worker transport, and the TDK to make agent-visible failures more
actionable while *reducing sensitive-data leakage*.
>
> In `arcade-core`, empty error messages now get placeholders,
`ToolOutputFactory.fail*` defaults blank messages, and input validation
errors are rewritten as field-level summaries that intentionally omit
rejected values (avoiding Pydantic echo of secrets). The `@tool`
fallback in `arcade-tdk` no longer surfaces `str(exception)` to agents;
it returns exception *type-only* in `message` while preserving full
detail in `developer_message`.
>
> Adds a shared `build_tool_error_log_extra` helper and updates
`arcade-serve` + `arcade-mcp-server` to emit consistent structured
WARNING logs (`error_*`, `tool_name`, optional toolkit/version) for
Datadog, while MCP error responses now append
`additional_prompt_content` and force `structuredContent=None` on
failures per spec. Includes extensive new tests and bumps package
versions (`arcade-core` 4.6.2, `arcade-tdk` 3.6.1, `arcade-mcp-server`
1.19.3, `arcade-serve` 3.2.3).
>
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
e5c7ebcaf56176cfbd8e6d1f2b6295352abd0ec0. Bugbot is set up for automated
code reviews on this repo. Configure
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<!-- /CURSOR_SUMMARY -->
---------
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
We recently added outputSchema support for our MCP tools (not yet for
worker routes yet). Today, we always return structuredContent. On tool
execution errors we return structuredContent: {"error": "..."} with
isError: True, even when that shape does not match the tool’s declared
outputSchema. Since the MCP spec says clients SHOULD validate
structuredContent against outputSchema, some clients reject these
responses.
Since structuredContent is optional, we’re going to omit it when
isError: true.
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> **Medium Risk**
> Changes the shape of tool error responses across the MCP server, which
may break clients or tools that previously relied on
`structuredContent["error"]` for failures. Behavior is more
spec-compliant but touches core request/response paths and test
expectations.
>
> **Overview**
> Prevents MCP tool error responses from violating a tool’s declared
`outputSchema` by **always setting `structuredContent=None` when
`isError=True`** (server execution errors, unknown tools, middleware
exceptions, and `Context.tools.call_raw` JSON-RPC errors).
>
> Updates requirement-failure error formatting to put the human-friendly
message in `content[0]` and (when present) serialize extra
machine-readable fields (e.g. `authorization_url`, `llm_instructions`)
into an additional `content` item. Examples and integration/unit tests
are updated to read errors from `content[0].text`, and
`arcade-mcp-server` is bumped to `1.19.2`.
>
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
4213bdd4aa44362de85c30f5f31c576243c132d5. Bugbot is set up for automated
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<!-- /CURSOR_SUMMARY -->
When a tool’s output TypedDict uses total=False, MCP clients reject the
response with:
```
MCP error -32602: Structured content does not match the tool's output schema
```
Note that the bug also exists for the Engine transport
(/worker/tools/execute), but since the engine doesn't validate the
output schema, the bug never surfaced. This PR addresses the problem
holistically (MCP and Engine) in preparation for a future where the
Engine transport validates output schemas.
Two bugs combined to cause this:
1. Schema: The outputSchema had no required array and declared all
fields as strict types (e.g. "type": "string"), making every field look
mandatory and non-null.
2. Serialization: model_dump() on TypedDict-derived Pydantic models
emitted None for absent optional fields. A tool returning {"name":
"hello"} produced {"name": "hello", "optional_field": null} which is a
value the schema forbids.
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> **Medium Risk**
> Adjusts core schema generation and MCP JSON Schema conversion for
TypedDicts, affecting how tool input/output contracts are emitted and
validated across clients; mistakes could break compatibility or
validation behavior.
>
> **Overview**
> Fixes MCP/engine validation failures for `TypedDict(total=False)`
outputs by ensuring absent optional keys are **omitted from serialized
output** and that emitted schemas correctly describe **required vs
optional** keys.
>
> `arcade-core` now tracks `required_keys`/`inner_required_keys` and
per-field `nullable` in `ValueSchema`, derives required sets from
TypedDict `__required_keys__`, and unwraps `Optional[T]` to support
optional nested TypedDicts; TypedDict-derived Pydantic models now
`model_dump(exclude_unset=True)` to avoid leaking missing fields as
`null`.
>
> `arcade-mcp-server` JSON Schema conversion now emits `required` arrays
(including for arrays of objects), supports `nullable` by generating
`type: [<type>, "null"]` (and `enum` including `None`), and treats
nullable top-level objects as valid unwrapped output schemas. Adds
focused unit/end-to-end tests plus an expanded example server
demonstrating total-false, mixed required/optional, nullable, and
optional-nested TypedDict outputs, and bumps package
versions/dependencies accordingly.
>
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
53fe8365f613053599130520b75f30b614b465ca. Bugbot is set up for automated
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<!-- /CURSOR_SUMMARY -->
Resolves
https://linear.app/arcadedev/issue/TOO-590/add-resources-support-to-server-framework
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> **Medium Risk**
> Adds new resource registration/reading semantics (including URI
templates and duplicate/multiple-match policies) and changes JSON Schema
generation for tool I/O, which may affect MCP client compatibility and
runtime behavior across servers.
>
> **Overview**
> **Adds first-class MCP Resources support across `arcade-mcp-server`.**
`MCPApp` can now register resources at build time via
`add_resource`/`@resource` plus convenience `add_text_resource` and
`add_file_resource`, and passes these through to `MCPServer` for startup
loading (including `ResourceTemplate` URIs with `{param}` and `{param*}`
matching).
>
> **Extends `ResourceManager` behavior.** Resource reads now coerce
handler return types (including raw `bytes` to base64
`BlobResourceContents`), support template matching with
overlap/multiple-match detection, and introduce configurable duplicate
handling policies.
>
> **Improves tool schema + MCP Apps linking.** Tool input/output JSON
Schema generation is refactored to recursively expand nested `json`
schemas and ensure `outputSchema` is always an object (wrapping
non-object returns in a `result` property); `MCPApp` also supports
attaching arbitrary tool `_meta` extensions (e.g., `ui.resourceUri`)
applied at server start.
>
> Adds two new example servers (`resources`, `tools_with_output_schema`)
and broad test coverage for resource templates, static/file resources,
meta extensions, and schema wrapping/recursion.
>
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
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<!-- /CURSOR_SUMMARY -->
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
**Implements**: [SEP-2448: server execution telemetry]
(https://github.com/modelcontextprotocol/modelcontextprotocol/pull/2448)
**Description:**
**The Observability Gap (The Problem)**
MCP clients propagate trace context to servers, but server-side
execution remains a black box. The client sees a single tools/call or
resources/read span; everything the server does (auth checks, policy
evaluation, API calls, sub-tool invocations) is invisible. In
cross-organization deployments, clients and servers use separate
observability backends with no shared collector access, making
traditional span export useless.
<img width="1015" height="450" alt="Screenshot 2026-03-23 at 3 43 21 PM"
src="https://github.com/user-attachments/assets/58c817b5-fee6-46a3-9877-d523a25368ad"
/>
**Server Execution Telemetry (The Solution)**
Servers advertise serverExecutionTelemetry and return a curated slice of
their execution spans directly in _meta.otel of the response. Clients
ingest these verbatim OTLP spans into their own collector, stitching
server-side execution into their distributed trace; no shared
infrastructure required. The black box becomes transparent.
<img width="945" height="574" alt="Screenshot 2026-03-23 at 3 43 44 PM"
src="https://github.com/user-attachments/assets/38d97c94-aa73-4e62-9b4e-3264600e5ed0"
/>
.
**Summary:**
Implement MCP serverExecutionTelemetry capability that enables
cross-organization distributed tracing by returning server-side
OpenTelemetry spans to clients inline via _meta.otel.traces.
Server-side (middleware):
- TelemetryPassbackMiddleware intercepts tools/call and resources/read
- ContextVarSpanCollector isolates span collection per-request via
ContextVar
- Propagates traceparent from client request for distributed trace
stitching
- Serializes collected spans to verbatim OTLP JSON (resourceSpans
format), directly POSTable to /v1/traces
- Top-level span filtering by default; full span tree via detailed
opt-in
- Middleware advertises capabilities via get_capabilities() on the
Middleware base class
- Provisional API: FutureWarning emitted until SEP-2448 is ratified
Client-side (reference agent):
- LangChain ReAct agent connects to MCP server via
streamable_http_client with OAuth 2.1
- Detects serverExecutionTelemetry capability at initialization
- Dynamically wraps discovered MCP tools with traceparent propagation
and _meta.otel span request
- Ingests returned server spans into Jaeger (OTLP JSON) and Galileo
(OTLP protobuf)
- Two-act demo: --no-passback (black box) vs default (full server-side
visibility)
Dependencies:
- opentelemetry-api and opentelemetry-sdk added to arcade-mcp-server
Bump arcade-mcp-server version to 1.18.0.
When a stdio server had a tool that didn't return a dict, then:
```
{
"code": "invalid_value",
"values": [
"object"
],
"path": [
"tools",
2,
"outputSchema",
"type"
],
"message": "Invalid input: expected \"object\""
}
```
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> **Medium Risk**
> Changes the generated `outputSchema` shape for all non-`json` return
types by wrapping them under a `result` property, which may affect
clients/tests expecting primitive/array schemas despite being
spec-correct.
>
> **Overview**
> Adjusts MCP tool `outputSchema` generation to **always** emit an
object schema, per the MCP spec that `structuredContent` must be a JSON
object.
>
> `json` outputs remain a direct object schema, while primitive/array
outputs are now wrapped as `{ "type": "object", "properties": {
"result": <inner> } }` (preserving `enum`/`items`), and tests are
expanded to cover these cases. Bumps `arcade-mcp-server` version to
`1.18.0`.
>
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
7dd13bd33d6fdf6ebb778e1a3d9167ca89806f55. This will update automatically
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<!-- /CURSOR_SUMMARY -->
Here's the PR summary:
---
## Enforce semver validation for `MCPApp` versioning
### Problem
`MCPApp.__init__` accepted any string as `version` with no validation.
Invalid versions like `"1.0.0dev"` or `"latest"` silently propagated to
the Engine, where `compareToolVersions` fell back to lexicographic
`strings.Compare` instead of `semver.Compare` — causing incorrect
ordering (e.g. `1.10.0 < 1.9.0`).
### Solution
Validate and normalize `version` at `MCPApp` instantiation time using
the same acceptance rules as Go's `golang.org/x/mod/semver v0.31.0` (the
exact version used by the Engine).
### Changes
**`arcade_mcp_server/_validation.py`** (new file)
- Shared regex constants: `SEMVER_PATTERN` (semver.org spec),
`SHORT_VERSION_PATTERN`, `MAJOR_ONLY_PATTERN`
**`arcade_mcp_server/mcp_app.py`**
- Added `_validate_version()` mirroring the existing `_validate_name()`
pattern
- Added `version` property + setter (validates on mutation too)
- `__init__` now stores `self._version` via `_validate_version()`
**`arcade_mcp_server/settings.py`**
- Added `@field_validator("version")` on `ServerSettings` — covers the
`MCP_SERVER_VERSION` env var path
- Fixed default from `"0.1.0dev"` → `"0.1.0"` (the old default was
itself invalid)
**`pyproject.toml`** — bumped `arcade-mcp-server` `1.17.4` → `1.17.5`
### Normalization pipeline
All inputs are normalized to canonical `MAJOR.MINOR.PATCH` before
storage:
| Input | Stored as |
|-------|-----------|
| `v1.0.0` | `1.0.0` |
| `1.0` / `v1.0` | `1.0.0` |
| `1` / `v1` | `1.0.0` |
### Verification
Validated against `golang.org/x/mod/semver v0.31.0` (Engine's exact
pinned version) — 40/40 accept/reject cases match. The Engine's own
`store_test.go` uses `"1.0"` and `"1.1"` as `ToolkitVersion` values,
confirming short forms are intentionally supported.
### Breaking change
Any user currently passing a non-semver version string (e.g.
`"1.0.0dev"`, `"latest"`) will get a `ValueError` on upgrade. This is
intentional — those versions were silently causing incorrect tool
ordering in the Engine.
Closes TOO-518
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> **Medium Risk**
> Introduces stricter version validation/normalization that will raise
errors for previously-accepted non-semver inputs (including via env
vars), which may break existing consumers depending on lax version
strings.
>
> **Overview**
> **Enforces semver for server versioning** across both `MCPApp` and
`ServerSettings`, rejecting invalid strings and normalizing accepted
inputs (e.g., stripping leading `v`, expanding `1`/`1.2` to
`1.0.0`/`1.2.0`).
>
> Adds shared `normalize_version` logic in
`arcade_mcp_server/_validation.py`, updates `MCPApp` to validate on init
and via a new `version` property/setter, and adds a Pydantic `version`
validator so `MCP_SERVER_VERSION` is checked. Defaults are updated from
`0.1.0dev` to `0.1.0`, tests are expanded to cover accept/reject cases,
and the package version is bumped to `1.17.5`.
>
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
2ceabacb25372e67eef9720b901c1ee2b214868f. This will update automatically
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---------
Co-authored-by: Eric Gustin <34000337+EricGustin@users.noreply.github.com>
Resolves TOO-201
Documentation PR for this is here:
https://github.com/ArcadeAI/docs/pull/626
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> **Medium Risk**
> Changes how environment variables/secrets are discovered and loaded,
which can subtly alter runtime behavior depending on directory structure
and existing env vars; bounded traversal and added tests reduce but
don’t eliminate this risk.
>
> **Overview**
> **Improves `.env` discovery across the MCP server and CLI.** Adds
`find_env_file()` (bounded by the nearest `pyproject.toml` by default)
and switches settings loading, `arcade deploy`, `arcade configure` stdio
env injection, and provider API-key resolution to use it.
>
> Updates dev reload to also watch the discovered `.env` even when it
lives outside the current working directory, adjusts `deploy --secrets
all` to only run when a `.env` was found, and moves the minimal
scaffold’s `.env.example` to the project root with updated
tests/integration checks. Version bumps align examples and top-level
deps with `arcade-mcp-server` `1.17.4` and `arcade-mcp` `1.11.2`.
>
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---------
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
When `python -m arcade_mcp_server` was executed, we would get the
following Runtime Warning:
```
<frozen runpy>:128: RuntimeWarning: 'arcade_mcp_server.__main__' found in sys.modules after import of package 'arcade_mcp_server', but prior to execution of 'arcade_mcp_server.__main__'; this may result in unpredictable behaviour
```
This PR resolves this. This PR is mainly just moving existing functions
to new locations; a refactor
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> **Low Risk**
> Primarily a module-organization refactor with minimal behavior change;
main risk is import-path regressions for internal callers and stdio/CLI
startup wiring.
>
> **Overview**
> Fixes the `python -m arcade_mcp_server` runtime warning by refactoring
`arcade_mcp_server.__main__` to be a thin CLI entrypoint and moving its
reusable logic into import-safe modules.
>
> Extracts stdio execution and tool discovery into a new
`arcade_mcp_server.stdio_runner` (`initialize_tool_catalog`,
`run_stdio_server`) and moves `setup_logging` into `logging_utils`,
updating `MCPApp`, the FastAPI `worker`, and tests to import from the
new locations. Bumps package version to `1.17.3`.
>
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<!-- CURSOR_SUMMARY -->
> [!NOTE]
> **Medium Risk**
> Touches authentication/login flow, credentials-file permissions, and
subprocess lifecycle behavior across platforms; while mostly defensive,
regressions could impact login or process management on Windows/macOS
runners.
>
> **Overview**
> Improves Windows/cross-platform reliability across the CLI and MCP
server: OAuth login now binds the callback server to `127.0.0.1`, avoids
slow loopback reverse-DNS, adds a configurable callback timeout
(`--timeout` + env default), and opens URLs via a Windows-friendly
`_open_browser` to avoid flashing console windows.
>
> Centralizes CLI output via a shared `console` that forces UTF-8 on
Windows, standardizes UTF-8 file reads/writes throughout, tightens
credentials-file permissions on Windows using `icacls`, and adds shared
Windows subprocess helpers for **no-window** process creation and
graceful termination (used by `deploy`, MCP reload, and usage-tracking
worker).
>
> Updates client configuration UX/robustness (Windows AppData resolution
via `platformdirs`, Cursor config path fallbacks + compatibility writes,
overwrite warnings, absolute `uv` path for GUI clients, safer path
display) and improves `deploy` child-process handling to avoid
pipe-buffer deadlocks while giving better debug-aware error messages.
>
> Expands CI to run tests on Linux/Windows/macOS, adds a no-auth CLI
integration workflow, disables usage tracking in toolkits CI, and adds
extensive regression tests for Windows signals, subprocess cleanup,
UTF-8, and config-path edge cases; bumps `arcade-core` to `4.4.2` and
`arcade-mcp-server` to `1.17.2` (with updated dependency pin).
>
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Add Attio to the wellknown OAuth2 provider classes so toolkits can use
Attio(scopes=[...]) instead of OAuth2(id=..., scopes=[...]).
---------
Co-authored-by: Eric Gustin <eric@arcade.dev>
When running `arcade_mcp_server` with `workers > 1`, uvicorn spawns
worker subprocesses that directly call `create_arcade_mcp_factory()`
without going through `main()`. Since `setup_logging()` is only called
in `main()`, these subprocesses have no logging configuration, causing:
1. Standard Python logging not intercepted by Loguru
2. DEBUG-level logs from libraries like urllib3 appearing when OTEL is
enabled
3. Inconsistent log formats between main process and workers
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> **Medium Risk**
> Touches process-wide logging initialization for uvicorn worker
subprocesses, which can affect log levels/handlers and output across the
server. Functional impact is limited to observability but could change
verbosity when OTEL or libraries emit logs.
>
> **Overview**
> Fixes multi-worker/reload mode logging by configuring Loguru inside
`create_arcade_mcp_factory()` (using `ARCADE_MCP_DEBUG` to set `INFO` vs
`DEBUG`) so uvicorn-spawned worker subprocesses get the same
logging/interception as `main()`.
>
> Adds regression tests that assert the factory filters DEBUG logs by
default and enables them when `ARCADE_MCP_DEBUG=true`, and bumps
`arcade-mcp-server` to `1.15.2`.
>
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<!-- /CURSOR_SUMMARY -->
1. Resolves
[TOO-363](https://linear.app/arcadedev/issue/TOO-363/arcade-deploy-fails-when-additional-deps-are-added-to-the-server).
2. Resolves
[TOO-364](https://linear.app/arcadedev/issue/TOO-364/arcade-cores-tool-skip-logic-is-missing-case-for-direct-execution).
3. Resolves
[TOO-358](https://linear.app/arcadedev/issue/TOO-358/missing-evals-error-message-shows-wrong-command).
4. Resolves
[TOO-365](https://linear.app/arcadedev/issue/TOO-365/arcade-evals-unit-tests-are-hanging).
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> **Medium Risk**
> Medium risk because it changes how `arcade deploy` spawns the server
process and adjusts toolkit discovery skip logic, which can affect
deployments and tool discovery; however, the changes are small and
covered by new unit/integration tests.
>
> **Overview**
> `arcade deploy` now starts the validation server using the project’s
`.venv` interpreter (via `find_python_interpreter`) instead of the CLI’s
own `sys.executable`, preventing missing dependency failures when the
CLI is installed in an isolated env.
>
> `arcade-core`’s `Toolkit.tools_from_directory` skip logic is hardened
to also skip the currently executing entrypoint by module name
(`__main__.__spec__.name`) when file paths don’t match (e.g., bundled
execution). CLI error printing now escapes plain messages to avoid rich
markup issues, and `arcade-evals` lock acquisition accepts an optional
timeout default.
>
> Adds unit tests for the new toolkit skip behavior and an integration
test that boots the MCP server via direct Python invocation to mirror
deployment behavior, and bumps `arcade-core`, `arcade-mcp-server`, and
root dependency versions accordingly.
>
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The 'MCP server started' events would fail to send to posthog if the CLI
was not installed. This PR fixes this by moving PostHog from being a
dependency of the CLI to a dependency of arcade-core.
<!-- CURSOR_SUMMARY -->
> [!NOTE]
> Aligns versions and dependency ranges across the CLI and server
packages; removes an unnecessary dependency.
>
> - Bump `arcade-mcp-server` to `1.14.2` and `arcade-mcp` to `1.8.1`
> - Update `arcade-core` constraint to `>=4.2.1,<5.0.0`; CLI now
requires `arcade-mcp-server>=1.14.2`
> - Remove `posthog` from CLI dependencies
>
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https://github.com/ArcadeAI/docs/pull/622 moved a lot of files to new
URLs
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> Updates references to Arcade docs after site restructure and bumps
package versions.
>
> - Update docs URLs in `README.md`, `SECURITY.md`, contrib READMEs
(CrewAI, LangChain), and CLI template README to new `/en/...` paths
> - Update `documentation_url` in `arcade_mcp_server/server.py` error
message to the new "compare server types" doc
> - Bump versions: `arcade-mcp-server` to `1.14.1` and root `arcade-mcp`
to `1.7.2`
>
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`arcade-mcp-server` version was not bumped in
https://github.com/ArcadeAI/arcade-mcp/pull/717, so this PR bumps
`arcade-mcp-server`, and then update's `arcade-mcp`'s dependency on
`arcade-mcp-server` by increasing the minimum version
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> Bumps arcade-mcp-server to 1.13.0, updates arcade-mcp to 1.6.2, and
raises related dependency minimums (including example auth server).
>
> - **Versions**:
> - Bump `libs/arcade-mcp-server` project version from `1.12.0` to
`1.13.0`.
> - Bump `arcade-mcp` package version from `1.6.1` to `1.6.2`.
> - **Dependencies**:
> - Raise `arcade-mcp` dependency on `arcade-mcp-server` to `>=1.13.0`
in `pyproject.toml` (including `all` extra).
> - Increase example server
`examples/mcp_servers/authorization/pyproject.toml` minimum
`arcade-mcp-server` to `>=1.12.0`.
>
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Fixes [PLT-720: Refactor CLI to support multiple orgs +
projects](https://linear.app/arcadedev/issue/PLT-720/refactor-cli-to-support-multiple-orgs-projects)
This PR removes the legacy login flow (login to get an API key) from
Arcade CLI. Believe it or not, this flow predates the ability to get an
API key from the Dashboard, or even the Dashboard itself!
Notable changes:
**Legacy handling** - When a user with an existing `credentials.yaml`
updates the CLI, they will get instructions on fixing their old
credentials:
<img width="978" height="146" alt="Screenshot 2025-12-08 at 10 10 37"
src="https://github.com/user-attachments/assets/5aeaef2c-bef7-4642-a2f7-f917b257c94b"
/>
Any commands that require login (non-public commands) will be blocked
with the above message until `arcade logout / arcade login` is performed
again.
**New login flow**
```sh
arcade login
Opening a browser to log you in...
✅ Logged in as nate@arcade.dev.
Active project: Nate Barbettini's organization / Default project
Run 'arcade org list' or 'arcade project list' to see available options.
```
**List and set the active organization**
```sh
arcade org list
┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━┳━━━━━━━━┓
┃ Name ┃ ID ┃ Default ┃ Active ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━╇━━━━━━━━┩
│ Nate Barbettini's organization │ 1c64968e-fdc5-4c55-8612-2ce46cd7881b │ ✓ │ ✓ │
│ Sergio 743 │ 1f1f6184-58dc-4bac-bdde-b9184e43fdf3 │ │ │
└────────────────────────────────┴──────────────────────────────────────┴─────────┴────────┘
Use 'arcade org set <org_id>' to switch organizations.
```
```sh
arcade org set 1c64968e-fdc5-4c55-8612-2ce46cd7881b
✓ Switched to organization: Nate Barbettini's organization
Active project: Default project
```
**List and set the active project**
```sh
arcade project list
Active organization: Nate Barbettini's organization
Use 'arcade org list' and 'arcade org set <org_id>' to switch organizations.
┏━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━┳━━━━━━━━┓
┃ Name ┃ ID ┃ Default ┃ Active ┃
┡━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━╇━━━━━━━━┩
│ Default project │ 35166bf3-6e68-481e-bf16-f747fadc6c22 │ ✓ │ ✓ │
│ Second project │ 62963205-31ea-4fda-9fc4-af10db89c06f │ │ │
└─────────────────┴──────────────────────────────────────┴─────────┴────────┘
Use 'arcade project set <project_id>' to switch projects.
```
```sh
arcade project set 35166bf3-6e68-481e-bf16-f747fadc6c22
✓ Switched to project: Default project
```
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> Migrates CLI to OAuth2 (PKCE) with saved org/project context, adds
org/project commands, rewrites Engine calls to org-scoped endpoints, and
bumps core packages.
>
> - **Auth & Config**
> - Implement OAuth2 Authorization Code + PKCE (`arcade_cli/authn.py`)
with local callback server and Jinja templates.
> - Persist tokens and active `context` (org/project) in
`credentials.yaml` via updated config models
(`arcade_core/config_model.py`).
> - Add token refresh and CLI config fetch utilities
(`arcade_core/auth_tokens.py`).
> - Detect legacy API-key credentials and block protected commands until
re-login; add `whoami` command.
> - **Org/Project Management**
> - New subcommands: `arcade org list|set`, `arcade project list|set`
(fetch via Coordinator).
> - **Engine API usage (org-scoped)**
> - Introduce org/project URL rewriting transports
(`arcade_core/network/org_transport.py`) and helpers
(`get_org_scoped_url`, `get_arcade_client`, `get_auth_headers`).
> - Update `deploy`, `server`, and `secret` commands to use Bearer
tokens and org-scoped paths; adjust log streaming/status, secrets CRUD,
and deployment workflows.
> - **CLI UX**
> - Replace legacy login URLs/constants; add success/failure HTML
templates for browser callback.
> - Tweak `dashboard` to health-check without credentials.
> - Usage tracking now includes `org_id`/`project_id` properties.
> - **Tests**
> - Update tests for dashboard, secrets, utils, and usage identity
(OAuth `/whoami`).
> - **Dependencies & Versions**
> - Bump packages: `arcade-core@4.0.0`, `arcade-mcp-server@1.12.0`,
`arcade-serve@3.2.0`, `arcade-tdk@3.3.0`; add `authlib`.
>
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# Valuable references for the reviewer:
- Docs PR: https://github.com/ArcadeAI/docs/pull/583
- Implements Phase 1 of the following planning doc:
https://linear.app/arcadedev/project/arcade-mcp-supports-mcp-auth-front-door-auth-7cbaa20cb054/overviewhttps://github.com/user-attachments/assets/79ad43fd-f5e8-4793-a1dd-18b35acefdc3
# PR Description
Adds OAuth 2.1 Resource Server authentication to arcade-mcp-server,
enabling HTTP MCP servers to validate Bearer tokens on every request.
This unlocks tool-level authorization and secrets support for HTTP
servers.
- Multiple authorization server support
- Granular token validation options (verify_exp, verify_iat, verify_iss)
- Environment variable configuration
- OAuth discovery metadata endpoint
(/.well-known/oauth-protected-resource)
- Extracts sub claim from token as context.user_id
- Lifts transport restrictions for tools requiring auth/secrets on HTTP
when protected
```python
from arcade_mcp_server import MCPApp
from arcade_mcp_server.resource_server import ResourceServerAuth, AuthorizationServerEntry
resource_server_auth = ResourceServerAuth(
canonical_url="http://127.0.0.1:8000/mcp",
authorization_servers=[
AuthorizationServerEntry(
authorization_server_url="https://auth.example.com",
issuer="https://auth.example.com",
jwks_uri="https://auth.example.com/jwks",
)
],
)
app = MCPApp(name="my_server", version="1.0.0", auth=resource_server_auth)
```
# Testing
Beyond the comprehensive unit tests, I also manually tested end-to-end
with WorkOS Authkit (DCR) and KeyCloak (non-DCR).
# Future Work
- CIMD support
- An `ArcadeResourceServer` to make adding front-door auth super easy
when using Arcade's Auth Server
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> Adds OAuth 2.1 front-door auth (JWKS validation + OAuth discovery) and
propagates user identity to tools, enabling auth/secret-requiring tools
over HTTP.
>
> - **Authentication (Front-Door OAuth 2.1)**
> - New `resource_server` module with `ResourceServerAuth`
(multi-authorization-server, metadata) and `JWKSTokenValidator`
(JWKS-based JWT validation) plus granular validation options.
> - ASGI `ResourceServerMiddleware` validates Bearer tokens on every
HTTP request and injects `resource_owner`.
> - OAuth discovery endpoint via FastAPI router at
`/.well-known/oauth-protected-resource[/<path>]`.
> - **Integration**
> - `MCPApp`/`worker` accept `auth`/`resource_server_validator`, mount
middleware, expose discovery; logs accepted auth servers.
> - HTTP transport (`http_streamable`) carries `SessionMessage` with
`resource_owner` from request → session.
> - `Context`/`Session`/`Server` plumb `resource_owner`; `Server`
selects `user_id` preferring token `sub`.
> - **Behavior Changes**
> - HTTP transport restriction lifted for tools requiring
`authorization`/`secrets` when request is authenticated; otherwise
blocked with actionable error.
> - **Configuration**
> - Env-var based auth config via `MCP_RESOURCE_SERVER_*` in
`MCPSettings.ResourceServerSettings`; `.env` auto-load.
> - **Telemetry**
> - Usage tracking records `resource_server_type` on server start.
> - **Examples**
> - New `examples/mcp_servers/authorization` sample server (HTTP auth,
secrets, Reddit tool) with Docker setup.
> - **Tests**
> - Extensive unit tests for validators, middleware, env config,
multi-AS, transport rules, and app integration.
> - **Version**
> - Bump `arcade-mcp-server` to `1.12.0`; minor docstring tweak in
`__init__.py`.
>
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Resolves TOO-152
Other packages that depend on `arcade_mcp_server` will now be able to
use the type information that `arcade_mcp_server` provides
Avoids mypy errors like the following:
`arcade_google_drive/tools/folders.py:12: error: Argument 1 to
"create_folder" becomes "Any" due to an unfollowed import
[no-any-unimported]`
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> Add `arcade_mcp_server/py.typed` to expose inline type hints and bump
package version to 1.11.2.
>
> - **Types**:
> - Add `arcade_mcp_server/py.typed` to publish inline type hints to
dependents.
> - **Packaging**:
> - Bump `version` in `libs/arcade-mcp-server/pyproject.toml` from
`1.11.1` to `1.11.2`.
>
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Update `arcade-core` and `arcade-tdk` dependency versions to resolve
`ImportError` caused by incompatible `Figma` auth provider imports.
The `Figma` OAuth2 provider was introduced in `arcade-core` 3.3.5.
`arcade-tdk` 3.2.0 and `arcade-mcp-server` 1.10.2 started importing
`Figma`, but their `pyproject.toml` dependency constraints were not
updated to require `arcade-core>=3.3.5`. This led to `ImportError` when
`arcade-tdk` or `arcade-mcp-server` were installed with an older
`arcade-core` version. This PR updates the minimum required versions in
`pyproject.toml` files across `arcade-tdk`, `arcade-mcp-server`, and the
root project to ensure compatibility.
---
Linear Issue:
[TOO-231](https://linear.app/arcadedev/issue/TOO-231/worker-fails-to-start-due-to-arcade-core-auth-import)
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<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> Align dependency minimums to `arcade-core>=3.3.5` and
`arcade-tdk>=3.2.0` and bump package versions across projects.
>
> - **Dependencies**:
> - Raise `arcade-core` minimum to `>=3.3.5,<4.0.0` in
`libs/arcade-mcp-server/pyproject.toml`,
`libs/arcade-tdk/pyproject.toml`, and root `pyproject.toml`.
> - Raise `arcade-tdk` minimum to `>=3.2.0,<4.0.0` in
`libs/arcade-mcp-server/pyproject.toml` and root `pyproject.toml`.
> - **Version bumps**:
> - `libs/arcade-mcp-server` version `1.10.2` → `1.10.3`.
> - `libs/arcade-tdk` version `3.2.0` → `3.2.1`.
> - Root package `arcade-mcp` version `1.5.6` → `1.5.7`.
>
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
abec5dff0d18c9e9c1c5a0ceafa73c67b6af661a. This will update automatically
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---------
Co-authored-by: Cursor Agent <cursoragent@cursor.com>
Closes TOO-192
<!-- CURSOR_SUMMARY -->
---
> [!NOTE]
> Adds a Figma OAuth2 auth provider and wires it through TDK and MCP
server, with tests updated and package versions bumped.
>
> - **Auth**:
> - Add `Figma` OAuth2 provider in
`libs/arcade-core/arcade_core/auth.py`.
> - **Exports**:
> - Expose `Figma` in
`libs/arcade-mcp-server/arcade_mcp_server/auth/__init__.py` and
`libs/arcade-tdk/arcade_tdk/auth/__init__.py` (`__all__`).
> - **Tests**:
> - Add Figma auth requirement test case in
`libs/tests/tool/test_create_tool_definition.py` and import `Figma`.
> - **Versioning**:
> - Bump `arcade-mcp-server` to `1.10.2` and `arcade-tdk` to `3.2.0`.
>
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
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---------
Co-authored-by: Francisco Liberal <francisco@arcade.dev>
This PR does three things:
1. Executes synchronous tool calls in thread pool allowing for up to 4 +
# of CPUs executions in parallel.
2. Makes force quitting via double SIGINT/SIGTERM possible and via
single SIGINT/SIGTERM + graceful shutdown timeout expiry possible, even
if there are active connections.
3. Sets `timeout_graceful_shutdown` to
`ARCADE_UVICORN_TIMEOUT_GRACEFUL_SHUTDOWN` env var if set, else defaults
to 15.
4. Disable the worker health check span to reduce noise
Tradeoffs:
Since this PR introduces executing synchronous tools via `await
asyncio.to_thread(func, **func_args)`, this means that there is no way
for the thread to be killed until it finishes. The ramifications of this
is that the force quitting logic that is also implemented in this PR has
to be very harsh `os._exit(1)` just in case there is a sync tool
actively executing. This means that `MCPApp` teardown logic will not
execute when force quitting is required. Although this was already the
case because we weren't previously able to force quit! This tradeoff is
justified for now since "parallel" tool executions will relieve us of
many worker timeouts that we are seeing in prod.
Future work:
Minimize/eliminate the need for `os._exit(1)` such that `MCPApp`
teardown logic will always execute, even when force quitting. The
solution will likely be moving away from `await asyncio.to_thread(func,
**func_args)` (while maintaining "parallelism" and then utilize the
`TaskTrackerMiddleware` introduced in this PR to cancel all of the
active HTTP requests.
Resolves PLT-713
Server start events were sometimes not being tracked because of a race
condition. Adding 150ms wait for now. Longer term solution:
https://app.clickup.com/t/86b7bm6kp
Other events do not suffer from this issue
#672 was a quick fix. This PR makes it a long term fix.
Whether a tool is added via `MCPApp.add_tools_from_module`,
`MCPApp.add_tool`, or `@app.tool`, the server's version and description
will be the same.
We are now tracking whether a tool call event happens. We track generic
"failure reasons" if the tool call fails. We DO NOT track names of
tools, tool parameters, or any PII.
Event name:
- MCP tool called
Properties:
- is_execution_success
- failure_reason - one of "missing requirements", "transport
restriction", "error during tool execution", "unknown tool", "internal
error calling tool" or doesn't exist in the case of successful tool
execution.
- arcade_mcp_server_version
- runtime_language
- os_type
- os_release
- device_timestamp
As always you can opt out via setting the `ARCADE_USAGE_TRACKING`
environment variable to 0.
# PR Description
Consider this PR the result of a full pass through of this repository.
## Add helper for adding tools to an `MCPApp`
You can now add all of the tools in a module to an `MCPApp` via
`app.add_tools_from_module(...)`
## Edit what `arcade new` generates
First, I updated the backend to use hatchling.
Second, the structure generated before this PR was simple, but did not
create a proper Python module.
This hindered developers in the following ways:
1. Difficult to add the tools in your server to an evaluation suite
2. Difficult to add more than one tool to an MCPApp at a time
3. All other niceties that come with being able to import modules
```
# Before
server/
├── .env.example
├── server.py
└── pyproject.toml
```
This PR updates the structure generated such that a valid Python module
is generated:
```
# After
server/
├── pyproject.toml
└── src/
└── server/
├── __init__.py
├── .env.example
└── server.py
```
## Fix Tool Chaining
`self._ctx.server.executor.run(...)` was being called, but `MCPServer`
does not have an instance of `ToolExecutor` (and it's not intended to be
an instance anyways). I updated `Tool.call_raw` to pass the programmatic
tool call through the `MCPServer._handle_call_tool`. This means that the
programmatic tool calls now go through the same steps that a typical
tool call (initiated by the MCP client) would.
This means that **toolA**, which specifies **requirementsA**, is
permitted to call **toolB**, which specifies **requirementsB**, without
needing to explicitly declare or satisfy **requirementsB**. I believe
this is acceptable because the secrets and/or auth token associated with
**toolB's** `Context` are not exposed to **toolA**, and the secrets
and/or auth token associated with **toolA's** `Context` are not exposed
to **toolB**.
## Fix User Elicitation
1. The read & write streams were created with a maximum queue size of 0.
I increased this to 100.
2. I updated `ServerSession`'s run loop to both read messages from the
stream & process them concurrently. This enables server initiated
requests (like user elicitation and progress reporting) to be handled
while tools are being executed. Otherwise, the server initiated requests
would wait for the tool to finish executing and the tool execution would
wait for the server initiated request to finish.
3.
## Fix Progress Reporting
Progress tokens sent by the client were not being stored. Therefore
there was no way to notify a client with progress updates. I am now
storing the `progressToken`, along with other `_meta` sent from the
client, in the `ServerSession`'s `_request_meta`. I am setting
`_request_meta` whenever the `MCPServer` is handling an incoming message
from a client.
## Fix handling of server names with spaces
Before:
Server name: "The simple server name"
Tool name: whisper_secret
Name seen by client: "The_simple_server_name_WhisperSecret"
After
Server name: "The simple server name"
Tool name: whisper_secret
Name seen by client: "TheSimpleServerName_WhisperSecret"
## Add Integration Tests
The stdio integration test is much more comprehensive than the http
integration test. These tests will let me sleep a bit more at night
## Add Example MCP Servers
Example servers for sampling, user-elicitation, progress reporting,
logging, tool chaining, combining prebuilt tools with custom tools, tool
secrets, tool auth, evaluations, and more!
## Add Docker template
Added a Docker template for running an MCP server in Docker (and removed
the old docker stuff)
Previously, MCPApp did not truly have reload capabilities. Instead, if
`reload=True`, then under the hood we would just change over to the
module execution code path (e.g., `arcade mcp`, or `python -m
arcade_mcp_server`). This was bad because custom `MCPApp` startup code
was not being executed and tools that were not added to `MCPApp`'s
catalog were being discovered and added to the server.
`MCPApp` now contains its own custom reload logic. It doesn't use
uvicorn's reload because uvicorn's discovery & factory pattern wasn't
the best fit for `MCPApp`'s self-contained pattern.
Now when `MCPApp.run(reload=True)` is called, `MCPApp` becomes the
parent process that manages reload itself.
