CoreEx: Add Subscriber (End-to-End)

Guides you through adding a complete new event or command subscriber in one sitting: gathers all context upfront, identifies the right scenario path, then invokes the appropriate L1 skills in sequence so you are never asked the same question twice.

When to Use

• Adding a brand-new subscriber to an existing CoreEx Subscribe host
• You know the event or command subject and want the full slice — contract, handler, optional orchestration, and tests — in one workflow
• Covers the event-data-sync and business-process scenarios; for a command (queue-based, needs a dedicated receiver in the Subscribe host) prefer `coreex-command-subscribe-e2e`, which also covers topology and Aspire

When Not to Use

• Modifying an existing subscriber handler — invoke coreex-subscriber directly
• Setting up the Subscribe host itself (it does not yet exist) — use coreex-scaffold
• Building an API endpoint — use coreex-api-e2e

Workflow Overview

1. Read Feature Configuration — resolve messaging-provider, outbox-enabled, data-provider (SqlServer / Postgres / Cosmos / None), and rop-enabled from the solution-root AGENTS.md before asking anything.
2. Interview — identify the subject, scenario, DTO needs, and whether state persistence is required; batch all questions into one turn.
3. Execute L1 sequence — invoke each applicable L1 skill in order, passing context resolved in steps 1–2; no repeated questions.
4. Validate — dotnet build; confirm the subscriber is registered and integration tests are present.

For full step-by-step guidance see `references/workflow.md`.

L1 Sequence

Step	Skill	Condition
1	`coreex-contract`	Only if a new event/command DTO type is needed
2	`coreex-db-migration`	Only for business-process scenario when a new local entity table is needed (data-provider ≠ None)
3	`coreex-repository`	Only when Step 2 runs
4	`coreex-app-service`	Only for command and business-process scenarios that need orchestration beyond a direct adapter/sync call
5	`coreex-subscriber`	Always
6	`coreex-test-subscribe`	Always

Scenario Paths at a Glance

Scenario	Steps that run
Command handler — inbound command triggers an app-service action	1 (if new DTO) → 4 → 5 → 6
Event-data-sync — inbound event replicates data into a local store via IXxxSyncAdapter	1 (if new DTO) → 5 → 6
Business-process choreography — inbound event triggers a multi-step business process	1 (if new DTO) → 2 + 3 (if new entity) → 4 → 5 → 6

Key References

• `/.github/instructions/coreex-event-subscribers.instructions.md` — subscriber conventions, ValueValidator, ErrorHandler, subject naming
• `/.github/instructions/coreex-application-services.instructions.md` — app-service orchestration and Result<T> pipeline
• `/.github/instructions/coreex-tests.instructions.md` — subscriber integration test conventions
• `/.github/instructions/coreex-host-setup.instructions.md` — Subscribe host DI registration