Verify tool-calling support before enabling CometAPI agent execution

General
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Verify tool-calling support before enabling CometAPI agent execution

If an AI SDK accepts a tools object, that is not yet a reason to turn on agent execution through CometAPI. Treat the integration as two decisions: whether the selected CometAPI model and route can complete the tool-call exchange you need, and where the resulting tool call will execute.

CometAPI’s documentation describes an OpenAI SDK-format integration: the usual setup changes the base_url and api_key. That is useful compatibility evidence, but it does not prove that every model or route supports tool calls. Before enabling the workflow, run a small contract check against the exact model and route you intend to use. Confirm that it can emit the expected tool-call shape and accept the corresponding tool result; record the model, route, schema, and failure behavior. If that evidence is missing, stop at text generation or choose a verified alternative rather than silently treating SDK compatibility as capability parity.

The execution boundary is a separate design choice. AI SDK documents execute as optional: the application may run the handler in the same process, or forward the call to a client or queue. Make that owner explicit. An in-process handler can be appropriate when the request is short-lived and the process owns its credentials and timeout. Forwarding is the safer boundary when work needs durable ownership, human approval, isolation, or retry policy. Omitting execute does not itself create a queue; your application still has to implement forwarding, correlation, authorization, and result delivery.

A practical checklist is:

  • Verify tool-call support for the exact CometAPI model and endpoint, rather than inferring it from the SDK format.
  • Test schema handling, tool-call and tool-result correlation, and the behavior when the model declines or emits an invalid call.
  • Name one execution owner: local handler, client, or queue. Define timeouts, retries, authorization, and the return path.
  • Keep the workflow disabled until both the model-route contract and the execution boundary are verified.

This approach keeps CometAPI’s API-format compatibility in its proper role: a way to integrate the client, not evidence that an untested model can safely drive your tools. Another provider could supply the same SDK-shaped interface, but changing the provider would change the model-and-route verification target; that is why the CometAPI-specific check remains material to this decision.

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I would split that contract check into two fixtures so a failure points to the right layer.

First, test the actual CometAPI model and route with a side-effect-free tool: for example, lookupTestOrder returning a fixed status for a synthetic order ID. Keep real service credentials out of the handler. Check the emitted arguments, return the fixture result under the corresponding tool-call ID, and inspect the continuation. A text answer that merely looks like a function call should not count as a completed tool exchange. This tests the selected route without risking a real order update.

Second, bypass model generation and inject calls directly into the application’s dispatcher: malformed arguments, an unauthorized order ID, and a duplicate delivery. Assert that rejected calls never reach the handler and that duplicate delivery cannot repeat a mutation. For a mutating tool, I would use an application-owned operation key rather than assume a newly generated tool-call ID identifies the same business action across retries.

These are proposed acceptance tests, not results for any CometAPI model. The useful distinction is that a successful live fixture provides narrow evidence about the model-route exchange, while dispatcher tests check your execution safeguards independently. Neither replaces the other, and the read-only fixture alone is not enough to enable a mutating tool.