Inline external call without durable fallback

warningexternal-call-inline-without-durable-path

A service that calls a third party synchronously, with no queue or workflow engine attached, has nowhere to park the request when the third party is slow or down. The failure becomes the user's problem instead of a retried job.

Severity: warning
Selects: every node of kind app-server
Components in scope: 99

What it checks

It looks at every node of kind app-server, and fires when:

— all of these hold:
— the node has at least one synchronous outgoing edge to a third-party-api
— this does not hold:
— the node has at least one connected edge joining a workflow-engine or queue

Message

Service '{{node.id}}' calls a third party inline with no queue or workflow engine to fall back to when that call fails.

{{node.id}} style paths are filled in from the node, the edge or the design the finding is about.

Applies to · 99 components

Application server app-server

Tripped by · 12

Reference designs whose broken twin names this rule in its header. The gate reads the same header, and fails when a rule no design trips.

coinbase-exchangereference doordash-deliveryreference grab-georeference hotel-reservationreference hotstar-streamingreference metrics-monitoringreference monzo-platformreference nubank-corereference snapchat-platformreference stripe-paymentsreference whatsapp-messagingreference zerodha-kitereference

Source

1# yaml-language-server: $schema=../schema/rule.schema.json
2# A service that calls a third party synchronously and has no queue or workflow engine
3# attached has nowhere to park the request when the third party is slow or down. The
4# failure becomes the user's problem instead of a retried job.
5# Tripped by: designs/doordash-delivery.broken.yaml
6schemaVersion: "1"
7type: "rule"
8id: "external-call-inline-without-durable-path"
9severity: "warning"
10select:
11  node:
12    kind: "app-server"
13when:
14  all:
15    - hasEdge:
16        direction: "out"
17        mode: "sync"
18        peerKind: "third-party-api"
19    - not:
20        hasEdge:
21          direction: "any"
22          peerKind: ["workflow-engine", "queue"]
23message: "Service '{{node.id}}' calls a third party inline with no queue or workflow engine to fall back to when that call fails."

The same page as markdown, for an agent: /catalogue/rules/external-call-inline-without-durable-path.md