feat: add safe artifact delete

docs/current_roadmap.md

@@ -33,16 +33,13 @@ clear operator feedback before adding more architecture.
   [`2026-06-09 product smoke RPC CLI`](superpowers/research/2026-06-09-product-smoke-rpc-cli.md).
 - Completed: `wf artifact inspect` now accepts `--version` as an alias for the
   positional version argument.
+- Completed: `wf artifact delete <artifact_id> <version> --confirm` deletes
+  unreferenced artifact versions and rejects versions still referenced by
+  deployments. Implementation:
+  [`wf artifact delete`](historical/superpowers/plans/2026-06-09-wf-artifact-delete.md).
 - Completed: `wf draft delete <workspace_id> --confirm` exposes existing draft
   workspace deletion as a safe CLI command. Implementation:
   [`wf draft delete CLI/RPC`](historical/superpowers/plans/2026-06-09-wf-draft-delete-cli-rpc.md).
-- Separate cleanup: design artifact deletion before exposing a command.
-  Deployments live in the artifact store and can reference artifact versions, so
-  `wf artifact delete <artifact_id> <version> --confirm` must reject referenced
-  artifacts by default. Active spec:
-  [`artifact delete policy`](superpowers/specs/2026-06-09-artifact-delete-policy.md).
-  Active plan:
-  [`wf artifact delete`](superpowers/plans/2026-06-09-wf-artifact-delete.md).
 - Next docs/ergonomics cleanup: explain raw MCP content-block envelopes returned
   by `cap call`, and only add a text-unwrapping CLI option if the safe behavior
   is explicitly defined.

docs/historical/superpowers/plans/2026-06-09-wf-artifact-delete.md

@@ -43,7 +43,7 @@ Implement the policy in [`artifact delete policy`](../specs/2026-06-09-artifact-
 - Modify: `src/wf_artifacts/store.py`
 - Test: `tests/artifacts/test_store.py`
 
-- [ ] **Step 1: Add failing tests for artifact delete**
+- [x] **Step 1: Add failing tests for artifact delete**
 
 In `tests/artifacts/test_store.py`, add:
 
@@ -99,7 +99,7 @@ def test_file_store_finds_deployments_for_artifact_version(tmp_path) -> None:
     ]
 ```
 
-- [ ] **Step 2: Run store tests and verify failure**
+- [x] **Step 2: Run store tests and verify failure**
 
 Run:
 
@@ -109,7 +109,7 @@ uv run pytest tests/artifacts/test_store.py -q
 
 Expected: FAIL because `delete_artifact` and `deployments_for_artifact` do not exist.
 
-- [ ] **Step 3: Add abstract store methods**
+- [x] **Step 3: Add abstract store methods**
 
 In `WorkflowArtifactStore`, add:
 
@@ -123,7 +123,7 @@ In `WorkflowArtifactStore`, add:
         raise NotImplementedError
 ```
 
-- [ ] **Step 4: Implement file store methods**
+- [x] **Step 4: Implement file store methods**
 
 In `FileWorkflowArtifactStore`, add:
 
@@ -149,7 +149,7 @@ In `FileWorkflowArtifactStore`, add:
 
 Keep sorting behavior from `list_deployments()`; do not add separate sort logic.
 
-- [ ] **Step 5: Run store tests**
+- [x] **Step 5: Run store tests**
 
 Run:
 
@@ -166,7 +166,7 @@ Expected: PASS.
 - Modify: `src/wf_api/surface.py`
 - Test: `tests/wf_api/test_artifact_api.py`
 
-- [ ] **Step 1: Add failing API tests**
+- [x] **Step 1: Add failing API tests**
 
 In `tests/wf_api/test_artifact_api.py`, add tests near `test_inspect_artifact_returns_stable_fields`:
 
@@ -216,7 +216,7 @@ from wf_artifacts import WorkflowDeployment
 
 If `pytest` is already imported in the file after prior edits, do not duplicate it.
 
-- [ ] **Step 2: Run API tests and verify failure**
+- [x] **Step 2: Run API tests and verify failure**
 
 Run:
 
@@ -226,7 +226,7 @@ uv run pytest tests/wf_api/test_artifact_api.py -q
 
 Expected: FAIL because `WorkflowArtifactApi.delete_artifact` does not exist.
 
-- [ ] **Step 3: Add surface method**
+- [x] **Step 3: Add surface method**
 
 In `src/wf_api/surface.py`, add to `WorkflowArtifactSurface`:
 
@@ -239,7 +239,7 @@ In `src/wf_api/surface.py`, add to `WorkflowArtifactSurface`:
     ) -> dict[str, Any]: ...
 ```
 
-- [ ] **Step 4: Implement API method**
+- [x] **Step 4: Implement API method**
 
 In `src/wf_api/artifacts.py`, add after `inspect_artifact`:
 
@@ -273,7 +273,7 @@ In `src/wf_api/artifacts.py`, add after `inspect_artifact`:
 
 If review objects to the `capability_id` string, use `artifact_capability_id` only if constructing a fake artifact is not required. Do not load the artifact after deletion just to build an event id.
 
-- [ ] **Step 5: Run API tests**
+- [x] **Step 5: Run API tests**
 
 Run:
 
@@ -292,7 +292,7 @@ Expected: PASS.
 - Test: `tests/wf_transport_rpc_http/test_app.py`
 - Test: `tests/wf_transport_rpc_http/test_client.py`
 
-- [ ] **Step 1: Add failing RPC/client tests**
+- [x] **Step 1: Add failing RPC/client tests**
 
 In `tests/wf_transport_rpc_http/test_app.py`, add an app-level method test that saves an artifact then calls:
 
@@ -317,7 +317,7 @@ assert deleted["deleted"] is True
 
 Use existing helpers in those files for building/saving artifacts. If no helper exists, create the artifact through `client.save_artifact(...)` using the existing artifact test payload pattern.
 
-- [ ] **Step 2: Run RPC tests and verify failure**
+- [x] **Step 2: Run RPC tests and verify failure**
 
 Run:
 
@@ -327,7 +327,7 @@ uv run pytest tests/wf_transport_rpc_http/test_app.py tests/wf_transport_rpc_htt
 
 Expected: FAIL because params/method/client method do not exist.
 
-- [ ] **Step 3: Add params model**
+- [x] **Step 3: Add params model**
 
 In `src/wf_transport_rpc_http/models.py`, add:
 
@@ -337,7 +337,7 @@ class DeleteArtifactParams(RpcParamsModel):
     version: int = Field(ge=1)
 ```
 
-- [ ] **Step 4: Register RPC method**
+- [x] **Step 4: Register RPC method**
 
 In `src/wf_transport_rpc_http/methods/artifacts.py`, import `DeleteArtifactParams` and add:
 
@@ -355,7 +355,7 @@ In `src/wf_transport_rpc_http/methods/artifacts.py`, import `DeleteArtifactParam
             raise_workflow_rpc_error(exc)
 ```
 
-- [ ] **Step 5: Add client method**
+- [x] **Step 5: Add client method**
 
 In `src/wf_transport_rpc_http/client/artifacts.py`, add:
 
@@ -369,7 +369,7 @@ In `src/wf_transport_rpc_http/client/artifacts.py`, add:
         )
 ```
 
-- [ ] **Step 6: Run RPC/client tests**
+- [x] **Step 6: Run RPC/client tests**
 
 Run:
 
@@ -385,7 +385,7 @@ Expected: PASS.
 - Modify: `src/wf_cli/commands/artifacts.py`
 - Test: `tests/wf_cli/test_remote_target.py` or `tests/wf_cli/test_artifacts.py`
 
-- [ ] **Step 1: Add CLI tests**
+- [x] **Step 1: Add CLI tests**
 
 Add tests for:
 
@@ -422,7 +422,7 @@ assert payload["deleted"] is False
 assert payload["blocked_by_deployments"] == ["echo.default"]
 ```
 
-- [ ] **Step 2: Run CLI tests and verify failure**
+- [x] **Step 2: Run CLI tests and verify failure**
 
 Run:
 
@@ -432,7 +432,7 @@ uv run pytest tests/wf_cli/test_remote_target.py -q
 
 Expected: FAIL because `wf artifact delete` does not exist.
 
-- [ ] **Step 3: Implement command**
+- [x] **Step 3: Implement command**
 
 In `src/wf_cli/commands/artifacts.py`, add:
 
@@ -465,7 +465,7 @@ def delete_artifact(
     )
 ```
 
-- [ ] **Step 4: Run CLI tests**
+- [x] **Step 4: Run CLI tests**
 
 Run:
 
@@ -482,7 +482,7 @@ Expected: PASS.
 - Modify: `docs/current_roadmap.md`
 - Modify: `docs/superpowers/specs/2026-06-09-artifact-delete-policy.md`
 
-- [ ] **Step 1: Document command**
+- [x] **Step 1: Document command**
 
 In `docs/wf_cli.md`, add:
 
@@ -492,11 +492,11 @@ wf artifact delete smoke_artifact_20260609 1 --confirm
 
 State that the command refuses to delete artifact versions referenced by deployments, and users should delete deployments first with `wf deploy delete <deployment_id>`.
 
-- [ ] **Step 2: Update roadmap**
+- [x] **Step 2: Update roadmap**
 
 In `docs/current_roadmap.md`, mark artifact delete complete under Priority 1 after implementation. Keep the artifact-delete policy spec linked as current behavior if it remains accurate.
 
-- [ ] **Step 3: Update policy spec status**
+- [x] **Step 3: Update policy spec status**
 
 At the top of `docs/superpowers/specs/2026-06-09-artifact-delete-policy.md`, add:
 
@@ -509,7 +509,7 @@ unreferenced artifact versions and rejects versions referenced by deployments.
 
 ## Task 6: Final Verification
 
-- [ ] **Step 1: Run focused tests**
+- [x] **Step 1: Run focused tests**
 
 Run:
 
@@ -519,7 +519,7 @@ uv run pytest tests/artifacts/test_store.py tests/wf_api/test_artifact_api.py te
 
 Expected: PASS.
 
-- [ ] **Step 2: Run changed-file lint/type checks**
+- [x] **Step 2: Run changed-file lint/type checks**
 
 Run:
 
@@ -530,7 +530,7 @@ uv run basedpyright --level error src/wf_artifacts/store.py src/wf_api/artifacts
 
 Expected: PASS. If global ruff reports unrelated pre-existing errors, scope the final report to changed-file lint and list the unrelated files separately.
 
-- [ ] **Step 3: Optional manual smoke**
+- [x] **Step 3: Optional manual smoke**
 
 Against a running server:
 

docs/superpowers/specs/2026-06-09-artifact-delete-policy.md

@@ -1,7 +1,12 @@
 # Artifact Delete Policy
 
-This is the current design contract for adding artifact deletion. It is separate
+## Status
-from `wf draft delete` because artifact deletion is not only CLI plumbing.
+
+Implemented: `wf artifact delete <artifact_id> <version> --confirm` deletes
+unreferenced artifact versions and rejects versions referenced by deployments.
+
+This is the current design contract for artifact deletion. It is separate from
+`wf draft delete` because artifact deletion is not only CLI plumbing.
 
 ## Current State
 
@@ -9,19 +14,20 @@ from `wf draft delete` because artifact deletion is not only CLI plumbing.
   through CLI/RPC.
 - Deployment deletion already exists and is stored through
   `WorkflowArtifactStore.delete_deployment`.
-- Artifact deletion does **not** exist yet as a store/API operation.
+- Artifact deletion exists as a store/API/RPC/CLI operation for one artifact
+  version at a time.
 - Deployments live in the artifact store area and can reference a specific
   `(artifact_id, version)`.
 
-This means `wf artifact delete <artifact_id> <version>` needs store-level policy,
+This means `wf artifact delete <artifact_id> <version>` enforces store-level
-not just a CLI command.
+policy, not just CLI confirmation.
 
 ## Required Safety Rule
 
 Artifact deletion must not remove an artifact version while any deployment
 references that artifact version.
 
-The first implementation should reject with structured output like:
+Deletion rejects referenced artifacts with structured output like:
 
 ```json
 {
@@ -35,7 +41,7 @@ The first implementation should reject with structured output like:
 The exact response can be adjusted to match existing API payload style, but it
 must include the blocking deployment ids.
 
-## Non-Goals For First Slice
+## Non-Goals
 
 - Do not cascade-delete deployments.
 - Do not delete runs.
@@ -55,7 +61,8 @@ The non-cascade path must remain the default.
 
 ## Implementation Shape
 
-Add store primitives first, then API, then transport, then CLI:
+The implemented shape is store primitives first, then API, then transport, then
+CLI:
 
 1. `WorkflowArtifactStore` gains an artifact-version delete method.
 2. `WorkflowArtifactStore` gains a helper to find deployments referencing
@@ -67,7 +74,7 @@ Add store primitives first, then API, then transport, then CLI:
 
 ## Test Requirements
 
-The first artifact-delete slice should include tests for:
+Artifact deletion should keep tests for:
 
 - Deleting an unreferenced artifact version succeeds.
 - Deleting a missing artifact version is idempotent only if the existing artifact
@@ -88,4 +95,3 @@ the artifact that deployment referenced.
 
 `wf artifact delete <artifact_id> <version>` removes an artifact version only
 after proving no deployment references it.
-

docs/wf_cli.md

@@ -251,6 +251,15 @@ wf artifact inspect concat_ws 1
 Artifacts are immutable saved workflow definitions. List output is compact by
 design; use `inspect` for full details.
 
+Delete an unreferenced artifact version:
+
+```bash
+wf artifact delete smoke_artifact_20260609 1 --confirm
+```
+
+The command refuses to delete artifact versions still referenced by deployments.
+Delete referencing deployments first with `wf deploy delete <deployment_id>`.
+
 ## Deployments
 
 Save a deployment from flags:

src/wf_api/artifacts.py

@@ -276,6 +276,32 @@ class WorkflowArtifactApi:
         artifact = self._artifact_store().get_artifact(artifact_id, version)
         return artifact.model_dump(mode="json")
 
+    async def delete_artifact(
+        self, *, artifact_id: str, version: int
+    ) -> dict[str, Any]:
+        store = self._artifact_store()
+        blockers = store.deployments_for_artifact(artifact_id, version)
+        blocker_ids = [deployment.id for deployment in blockers]
+        if blocker_ids:
+            return {
+                "artifact_id": artifact_id,
+                "version": version,
+                "deleted": False,
+                "blocked_by_deployments": blocker_ids,
+            }
+        store.delete_artifact(artifact_id, version)
+        self.context.events.record_workflow_event(
+            "workflow_artifact_deleted",
+            capability_id=f"{artifact_id}@{version}",
+            payload={"artifact_id": artifact_id, "version": version},
+        )
+        return {
+            "artifact_id": artifact_id,
+            "version": version,
+            "deleted": True,
+            "blocked_by_deployments": [],
+        }
+
 
 def _suggested_self_bindings(required_sources: Sequence[str]) -> dict[str, str]:
     """Suggest local bindings for built-in sources that deploy to themselves."""

src/wf_api/service.py

@@ -95,6 +95,17 @@ class WorkflowApi:
             version=version,
         )
 
+    async def delete_artifact(
+        self,
+        *,
+        artifact_id: str,
+        version: int,
+    ) -> dict[str, Any]:
+        return await self.artifacts.delete_artifact(
+            artifact_id=artifact_id,
+            version=version,
+        )
+
     async def save_artifact(
         self,
         artifact: dict[str, Any],

src/wf_api/surface.py

@@ -137,6 +137,13 @@ class WorkflowArtifactSurface(Protocol):
         version: int,
     ) -> dict[str, Any]: ...
 
+    async def delete_artifact(
+        self,
+        *,
+        artifact_id: str,
+        version: int,
+    ) -> dict[str, Any]: ...
+
 
 class WorkflowDeploymentSurface(Protocol):
     """Deployment methods exposed by workflow frontends."""

src/wf_artifacts/store.py

@@ -43,6 +43,14 @@ class WorkflowArtifactStore:
     def list_deployments(self) -> list[WorkflowDeployment]:
         raise NotImplementedError
 
+    def delete_artifact(self, artifact_id: str, version: int) -> None:
+        raise NotImplementedError
+
+    def deployments_for_artifact(
+        self, artifact_id: str, version: int
+    ) -> list[WorkflowDeployment]:
+        raise NotImplementedError
+
     def delete_deployment(self, deployment_id: str) -> None:
         raise NotImplementedError
 
@@ -118,6 +126,24 @@ class FileWorkflowArtifactStore(WorkflowArtifactStore):
             )
         return deployments
 
+    def delete_artifact(self, artifact_id: str, version: int) -> None:
+        """Remove one immutable artifact version from the store."""
+        path = self._artifact_dir(artifact_id) / self._artifact_filename(version)
+        if not path.exists():
+            raise KeyError(f"unknown workflow artifact {artifact_id}@{version}")
+        path.unlink()
+
+    def deployments_for_artifact(
+        self, artifact_id: str, version: int
+    ) -> list[WorkflowDeployment]:
+        """Return deployments that currently reference one artifact version."""
+        return [
+            deployment
+            for deployment in self.list_deployments()
+            if deployment.artifact_id == artifact_id
+            and deployment.artifact_version == version
+        ]
+
     def delete_deployment(self, deployment_id: str) -> None:
         """Remove one mutable deployment binding record from the store."""
         path = self._deployment_path(deployment_id)

src/wf_cli/commands/artifacts.py

@@ -96,3 +96,31 @@ def _resolve_artifact_version(
         return version_option
     assert version_arg is not None
     return version_arg
+
+
+@app.command("delete")
+def delete_artifact(
+    ctx: typer.Context,
+    artifact_id: Annotated[str, typer.Argument(help="Artifact id.")],
+    version: Annotated[int, typer.Argument(min=1, help="Artifact version.")],
+    confirm: Annotated[
+        bool,
+        typer.Option(
+            "--confirm",
+            help="Required confirmation for deleting an artifact version.",
+        ),
+    ] = False,
+) -> None:
+    """Delete one unreferenced artifact version."""
+    if not confirm:
+        raise typer.BadParameter("pass --confirm to delete an artifact version")
+    context = load_cli_context(ctx)
+    emit_json(
+        run_cli_operation(
+            context,
+            context.handlers.delete_artifact(
+                artifact_id=artifact_id,
+                version=version,
+            ),
+        )
+    )

src/wf_transport_rpc_http/client/artifacts.py

@@ -38,3 +38,11 @@ class RpcArtifactClientMixin:
         self: RpcCaller, artifact: dict[str, Any]
     ) -> dict[str, Any]:
         return await self._call("workflow.artifacts.save", {"artifact": artifact})
+
+    async def delete_artifact(
+        self: RpcCaller, *, artifact_id: str, version: int
+    ) -> dict[str, Any]:
+        return await self._call(
+            "workflow.artifacts.delete",
+            {"artifact_id": artifact_id, "version": version},
+        )

src/wf_transport_rpc_http/methods/artifacts.py

@@ -7,7 +7,12 @@ import fastapi_jsonrpc as jsonrpc
 from wf_server import WorkflowServer
 
 from ..errors import WorkflowRpcError, raise_workflow_rpc_error
-from ..models import InspectArtifactParams, ListArtifactsParams, SaveArtifactParams
+from ..models import (
+    DeleteArtifactParams,
+    InspectArtifactParams,
+    ListArtifactsParams,
+    SaveArtifactParams,
+)
 from ..params import RpcParams
 
 
@@ -51,3 +56,15 @@ def register_methods(
             )
         except (ValueError, KeyError, LookupError, FileNotFoundError) as exc:
             raise_workflow_rpc_error(exc)
+
+    @entrypoint.method(name="workflow.artifacts.delete", errors=[WorkflowRpcError])
+    async def workflow_artifacts_delete(
+        params: DeleteArtifactParams = RpcParams(),
+    ) -> dict[str, Any]:
+        try:
+            return await server.api.delete_artifact(
+                artifact_id=params.artifact_id,
+                version=params.version,
+            )
+        except (ValueError, KeyError, LookupError, FileNotFoundError) as exc:
+            raise_workflow_rpc_error(exc)

src/wf_transport_rpc_http/models.py

@@ -152,6 +152,11 @@ class InspectArtifactParams(RpcParamsModel):
     version: int = Field(ge=1)
 
 
+class DeleteArtifactParams(RpcParamsModel):
+    artifact_id: str = Field(min_length=1)
+    version: int = Field(ge=1)
+
+
 class ListDeploymentsParams(RpcParamsModel):
     pass
 

tests/artifacts/test_store.py

@@ -219,3 +219,54 @@ def test_file_store_rejects_deployment_lookup_path_traversal(tmp_path) -> None:
 
     with pytest.raises(ValueError, match="deployment_id"):
         store.get_deployment("../outside")
+
+
+def test_file_store_deletes_one_artifact_version(tmp_path) -> None:
+    store = FileWorkflowArtifactStore(tmp_path)
+    store.save_artifact(artifact(1))
+    store.save_artifact(artifact(2))
+
+    store.delete_artifact("summarize_docs", 1)
+
+    with pytest.raises(KeyError, match="unknown workflow artifact"):
+        store.get_artifact("summarize_docs", 1)
+    assert store.get_artifact("summarize_docs", 2).version == 2
+
+
+def test_file_store_delete_artifact_missing_version_raises_key_error(tmp_path) -> None:
+    store = FileWorkflowArtifactStore(tmp_path)
+
+    with pytest.raises(KeyError, match="unknown workflow artifact"):
+        store.delete_artifact("summarize_docs", 1)
+
+
+def test_file_store_finds_deployments_for_artifact_version(tmp_path) -> None:
+    store = FileWorkflowArtifactStore(tmp_path)
+    store.save_deployment(
+        WorkflowDeployment(
+            id="summarize_docs.work",
+            artifact_id="summarize_docs",
+            artifact_version=1,
+        )
+    )
+    store.save_deployment(
+        WorkflowDeployment(
+            id="summarize_docs.personal",
+            artifact_id="summarize_docs",
+            artifact_version=1,
+        )
+    )
+    store.save_deployment(
+        WorkflowDeployment(
+            id="summarize_docs.v2",
+            artifact_id="summarize_docs",
+            artifact_version=2,
+        )
+    )
+
+    blockers = store.deployments_for_artifact("summarize_docs", 1)
+
+    assert [deployment.id for deployment in blockers] == [
+        "summarize_docs.personal",
+        "summarize_docs.work",
+    ]

tests/wf_api/test_artifact_api.py

@@ -7,6 +7,8 @@ from dataclasses import replace
 from pathlib import Path
 from typing import Any
 
+import pytest
+
 from tests.wf_mcp.test_support import echo_tool
 from wf_api.artifacts import WorkflowArtifactApi
 from wf_artifacts import (
@@ -14,6 +16,7 @@ from wf_artifacts import (
     FileWorkflowArtifactStore,
     RequiredCapability,
     WorkflowArtifact,
+    WorkflowDeployment,
 )
 from wf_mcp.broker import WfMcpService
 from wf_mcp.broker.service.workflow_operation_context import context_from_service
@@ -276,3 +279,39 @@ def test_handler_delegation_for_inspect_artifact(tmp_path: Path) -> None:
     assert handler_result["id"] == api_result["id"]
     assert handler_result["version"] == api_result["version"]
     assert handler_result["title"] == api_result["title"]
+
+
+def test_delete_artifact_deletes_unreferenced_version(tmp_path: Path) -> None:
+    artifact_store = FileWorkflowArtifactStore(tmp_path / "artifacts_delete")
+    api, _service = _artifact_api(artifact_store)
+    artifact_store.save_artifact(_echo_artifact())
+
+    result = asyncio.run(api.delete_artifact(artifact_id="echo", version=1))
+
+    assert result["artifact_id"] == "echo"
+    assert result["version"] == 1
+    assert result["deleted"] is True
+    assert result["blocked_by_deployments"] == []
+    with pytest.raises(KeyError, match="unknown workflow artifact"):
+        artifact_store.get_artifact("echo", 1)
+
+
+def test_delete_artifact_rejects_referenced_version(tmp_path: Path) -> None:
+    artifact_store = FileWorkflowArtifactStore(tmp_path / "artifacts_delete_blocked")
+    api, _service = _artifact_api(artifact_store)
+    artifact_store.save_artifact(_echo_artifact())
+    artifact_store.save_deployment(
+        WorkflowDeployment(
+            id="echo.default",
+            artifact_id="echo",
+            artifact_version=1,
+        )
+    )
+
+    result = asyncio.run(api.delete_artifact(artifact_id="echo", version=1))
+
+    assert result["artifact_id"] == "echo"
+    assert result["version"] == 1
+    assert result["deleted"] is False
+    assert result["blocked_by_deployments"] == ["echo.default"]
+    assert artifact_store.get_artifact("echo", 1).id == "echo"

tests/wf_cli/test_artifacts.py

@@ -22,12 +22,50 @@ class _ArtifactHandlers:
         self.calls.append((artifact_id, version))
         return {"id": artifact_id, "version": version}
 
+    async def delete_artifact(
+        self,
+        *,
+        artifact_id: str,
+        version: int,
+    ) -> dict[str, Any]:
+        self.calls.append((artifact_id, version))
+        return {
+            "artifact_id": artifact_id,
+            "version": version,
+            "deleted": True,
+            "blocked_by_deployments": [],
+        }
+
+
+class _BlockedArtifactHandlers:
+    def __init__(self) -> None:
+        self.calls: list[tuple[str, int]] = []
+
+    async def delete_artifact(
+        self,
+        *,
+        artifact_id: str,
+        version: int,
+    ) -> dict[str, Any]:
+        self.calls.append((artifact_id, version))
+        return {
+            "artifact_id": artifact_id,
+            "version": version,
+            "deleted": False,
+            "blocked_by_deployments": ["echo.default"],
+        }
+
 
 @dataclass(frozen=True)
 class _Context:
     handlers: _ArtifactHandlers
 
 
+@dataclass(frozen=True)
+class _BlockedContext:
+    handlers: _BlockedArtifactHandlers
+
+
 def test_artifact_inspect_accepts_version_option(monkeypatch) -> None:
     handlers = _ArtifactHandlers()
     monkeypatch.setattr(
@@ -57,3 +95,52 @@ def test_artifact_inspect_keeps_positional_version(monkeypatch) -> None:
     assert result.exit_code == 0, result.output
     assert json.loads(result.output) == {"id": "demo_artifact", "version": 3}
     assert handlers.calls == [("demo_artifact", 3)]
+
+
+def test_artifact_delete_requires_confirm(monkeypatch) -> None:
+    handlers = _ArtifactHandlers()
+    monkeypatch.setattr(
+        "wf_cli.commands.artifacts.load_cli_context",
+        lambda _ctx: _Context(handlers=handlers),
+    )
+
+    result = CliRunner().invoke(app, ["artifact", "delete", "echo", "1"])
+
+    assert result.exit_code != 0
+    assert "confirm" in result.output.lower()
+
+
+def test_artifact_delete_confirmed_succeeds(monkeypatch) -> None:
+    handlers = _ArtifactHandlers()
+    monkeypatch.setattr(
+        "wf_cli.commands.artifacts.load_cli_context",
+        lambda _ctx: _Context(handlers=handlers),
+    )
+
+    result = CliRunner().invoke(
+        app, ["artifact", "delete", "echo", "1", "--confirm"]
+    )
+
+    assert result.exit_code == 0, result.output
+    payload = json.loads(result.output)
+    assert payload["artifact_id"] == "echo"
+    assert payload["version"] == 1
+    assert payload["deleted"] is True
+    assert handlers.calls == [("echo", 1)]
+
+
+def test_artifact_delete_blocked_returns_blocker_ids(monkeypatch) -> None:
+    handlers = _BlockedArtifactHandlers()
+    monkeypatch.setattr(
+        "wf_cli.commands.artifacts.load_cli_context",
+        lambda _ctx: _BlockedContext(handlers=handlers),
+    )
+
+    result = CliRunner().invoke(
+        app, ["artifact", "delete", "echo", "1", "--confirm"]
+    )
+
+    assert result.exit_code == 0, result.output
+    payload = json.loads(result.output)
+    assert payload["deleted"] is False
+    assert payload["blocked_by_deployments"] == ["echo.default"]

tests/wf_transport_rpc_http/test_app.py

@@ -336,6 +336,31 @@ async def test_rpc_draft_workspace_delete(tmp_path) -> None:
         assert payload["result"]["deleted"] is True
 
 
+async def test_rpc_artifact_delete(tmp_path) -> None:
+    server = build_local_static_workflow_server(tmp_path / "store")
+    await server.api.create_artifact_from_plan(
+        artifact_id="delete_artifact",
+        version=1,
+        title="Delete Me",
+        plan=_constant_plan(),
+        outcomes=["ok"],
+        source_bindings={"wf.std": "wf.std"},
+    )
+
+    app = create_rpc_app(server)
+    transport = httpx.ASGITransport(app=app)
+    async with httpx.AsyncClient(transport=transport, base_url="http://test") as client:
+        payload = await _rpc(
+            client,
+            "workflow.artifacts.delete",
+            {"artifact_id": "delete_artifact", "version": 1},
+        )
+        assert payload["result"]["artifact_id"] == "delete_artifact"
+        assert payload["result"]["version"] == 1
+        assert payload["result"]["deleted"] is True
+        assert payload["result"]["blocked_by_deployments"] == []
+
+
 def _constant_plan() -> RawWorkflowPlan:
     return RawWorkflowPlan.model_validate(
         {

tests/wf_transport_rpc_http/test_client.py

@@ -346,3 +346,29 @@ async def test_rpc_workflow_client_deletes_draft_workspace(tmp_path) -> None:
         deleted_again = await client.delete_draft_workspace(workspace_id="delete-me")
         assert deleted_again["workspace_id"] == "delete-me"
         assert deleted_again["deleted"] is False
+
+
+async def test_rpc_workflow_client_deletes_artifact(tmp_path) -> None:
+    server = build_local_static_workflow_server(tmp_path / "store")
+    await server.api.create_artifact_from_plan(
+        artifact_id="delete_artifact",
+        version=1,
+        title="Delete Me",
+        plan=_constant_plan(),
+        outcomes=["ok"],
+        source_bindings={"wf.std": "wf.std"},
+    )
+
+    app = create_rpc_app(server)
+    transport = httpx.ASGITransport(app=app)
+    async with httpx.AsyncClient(
+        transport=transport, base_url="http://test"
+    ) as http_client:
+        client = RpcWorkflowApiClient(
+            url="http://test/rpc", timeout_seconds=5, http_client=http_client
+        )
+        deleted = await client.delete_artifact(artifact_id="delete_artifact", version=1)
+
+    assert deleted["deleted"] is True
+    assert deleted["artifact_id"] == "delete_artifact"
+    assert deleted["version"] == 1