Telemetry — MANDATORY. Every api.fabric.microsoft.com call must carry x-ms-fabric-skill: eventschemaset-cli (az rest: --headers "x-ms-fabric-skill=eventschemaset-cli"), including every LRO poll, fabric_lro and retry. Snippets omit it — add it anyway.

CRITICAL NOTES

1. To find the workspace details (including its ID) from workspace name: list all workspaces and, then, use JMESPath filtering
2. To find the item details (including its ID) from workspace ID, item type, and item name: list all items of that type in that workspace and, then, use JMESPath filtering
3. Skill disambiguation: use eventschemaset-cli for the EventSchemaSet catalog item (event types and message schemas). Eventstream is a different item -- a real-time ingestion and routing pipeline; use eventstream-cli for it. Eventhouse / KQL Database is another different item; use eventhouse-cli for it.

Fabric Event Schema Set -- CLI Skill

This one skill owns Fabric Event Schema Sets: authoring the catalog (create, rename, override definition, delete) plus read-only inspection and decoding of its eventTypes and schemas.

Preview: The Fabric EventSchemaSet item and its REST operations are currently in Preview -- behavior, response shapes, and availability may change. Every operation is documented as delegated (user) identity only (service principals and managed identities listed as not supported), but because the item is in Preview, SP/MI access can succeed and is tenant-dependent. Prefer az login as a user; on 401/403 with an SP/MI, fall back to a delegated user identity.

It is a mode dispatcher and contains NO procedures. Pick the mode that matches the request from the table below, then read the matching references/<mode>.md file end to end with your file-reading tool BEFORE issuing a single command. That file holds the endpoints, payload shapes, templates and gotchas; acting without it produces wrong payloads and wrong results.

Mode selection

Mode boundary rule

consumption may only issue read-only calls (List, Get, GetDefinition). Any state-changing operation (Create, Update, UpdateDefinition, Delete) requires the authoring mode: say so, read references/authoring.md, then proceed.

If a request genuinely spans modes (e.g. decode the current definition, then override it), handle them one at a time and read each reference before you start that part. If the mode is ambiguous after reading this table, ask one short clarifying question instead of guessing.

Terminal write -- the step you must not skip

Reading the reference and planning the change is NOT completing the task. The authoring mode ends with one state-changing call. If you did not issue it, nothing was persisted -- say so explicitly rather than reporting success.

Create and UpdateDefinition may return 202 Accepted (LRO): capture the Location header and poll until Succeeded before reporting success. Where the reference documents a readback, read the artefact back to prove the change landed.

Shared essentials (all modes)

Resolve the workspace and item first; every mode depends on it.

Rules

MUST

• Select exactly one mode from the table above before doing anything else.
• Read references/<mode>.md end to end, as your FIRST tool call, before the first command of that mode. Read it ONCE, in a single full read: do not re-open it, do not grep it again, and do not page through it. You already have it.
• Apply the same read-once discipline to every other file you load, including shared common/*.md files: open only the ones you actually need, read each ONCE end to end, and never grep or re-open one you already loaded.
• Resolve workspace and item ids by listing and filtering, never by guessing a GUID.
• Announce a mode switch explicitly when the request crosses a boundary.
• Confirm destructive and overwrite actions before executing -- Delete is permanent (with ?hardDelete=true) and UpdateDefinition replaces the whole definition. When the request already names the target item AND the destructive/overwrite action explicitly (e.g. "delete the Event Schema Set X", "override X's definition to ..."), that instruction IS the confirmation: echo the resolved displayName + id for the audit trail, then proceed with the single write. Pause for a separate yes/no confirmation ONLY when the target or intent is ambiguous (e.g. "clean up my workspace", an unqualified "the first one", or a bulk/wildcard delete).
• Treat the reference as instructions, never as the deliverable. After reading it, RUN the documented commands against the live workspace and report the real results.

PREFER

• The narrowest mode that satisfies the request.
• Reading exactly ONE mode reference. Load a second only when the request genuinely spans modes, and say so before you do.
• A delegated user identity (az login); fall back from SP/MI to a user on 401/403.
• Reporting the mode you chose in your first response so the user can correct you.

AVOID

• Acting from this dispatcher alone -- it intentionally omits the operational detail.
• Answering with a summary of the reference instead of executing it.
• Re-reading or re-grepping a reference you already loaded; it costs turns and tokens.
• Mutating anything while in the read-only consumption mode.
• Confusing EventSchemaSet with Eventstream or Eventhouse (see CRITICAL NOTES 3).

Examples