feat: assign issues to milestones on create/update (#22)

Add a `milestone` argument to `create_issue` and `update_issue` accepting
either a numeric milestone id or a title (resolved case-insensitively against
open and closed milestones, with a clear error for unknown titles). On
`update_issue`, `milestone: 0` clears the milestone. A BeforeValidator rejects
booleans so they are not silently coerced to an id.

Gitea Projects (Kanban boards) were investigated for #22 and are intentionally
left unsupported: Gitea 1.26.2 exposes no project endpoints in its REST API.
Documented this in api-reference.md and refreshed the (stale) write-mode tool
list to cover all 16 write tools.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/aegis_gitea_mcp/gitea_client.py

@@ -621,6 +621,41 @@ class GiteaClient:
             )
         return ids
 
+    async def _resolve_milestone_id(
+        self, owner: str, repo: str, milestone: int | str, *, correlation_id: str
+    ) -> int:
+        """Resolve a milestone id or title to a numeric milestone id.
+
+        Gitea's issue API requires a numeric milestone id. An integer is used
+        as-is (``0`` clears the milestone); a string is resolved
+        case-insensitively against the repository's milestones (open or closed)
+        and raises a clear error when no title matches.
+        """
+        if isinstance(milestone, int):
+            return milestone
+        title = milestone.strip()
+        existing = await self._request(
+            "GET",
+            f"/api/v1/repos/{quote(owner, safe='')}/{quote(repo, safe='')}/milestones",
+            params={"state": "all", "limit": 100},
+            correlation_id=correlation_id,
+        )
+        by_title: dict[str, int] = {}
+        if isinstance(existing, list):
+            for item in existing:
+                if isinstance(item, dict):
+                    m_title = str(item.get("title", ""))
+                    m_id = item.get("id")
+                    if m_title and isinstance(m_id, int):
+                        by_title[m_title.lower()] = m_id
+        match = by_title.get(title.lower())
+        if match is None:
+            raise GiteaError(
+                f"Unknown milestone for {owner}/{repo}: {title}. "
+                "Create it first with create_milestone."
+            )
+        return match
+
     async def create_issue(
         self,
         owner: str,
@@ -630,6 +665,7 @@ class GiteaClient:
         body: str,
         labels: list[str] | None = None,
         assignees: list[str] | None = None,
+        milestone: int | str | None = None,
     ) -> dict[str, Any]:
         """Create repository issue."""
         correlation_id = str(
@@ -642,6 +678,10 @@ class GiteaClient:
             )
         if assignees:
             payload["assignees"] = assignees
+        if milestone is not None:
+            payload["milestone"] = await self._resolve_milestone_id(
+                owner, repo, milestone, correlation_id=correlation_id
+            )
         result = await self._request(
             "POST",
             f"/api/v1/repos/{quote(owner, safe='')}/{quote(repo, safe='')}/issues",
@@ -659,8 +699,12 @@ class GiteaClient:
         title: str | None = None,
         body: str | None = None,
         state: str | None = None,
+        milestone: int | str | None = None,
     ) -> dict[str, Any]:
         """Update issue fields."""
+        correlation_id = str(
+            self.audit.log_tool_invocation(tool_name="update_issue", result_status="pending")
+        )
         payload: dict[str, Any] = {}
         if title is not None:
             payload["title"] = title
@@ -668,13 +712,15 @@ class GiteaClient:
             payload["body"] = body
         if state is not None:
             payload["state"] = state
+        if milestone is not None:
+            payload["milestone"] = await self._resolve_milestone_id(
+                owner, repo, milestone, correlation_id=correlation_id
+            )
         result = await self._request(
             "PATCH",
             f"/api/v1/repos/{quote(owner, safe='')}/{quote(repo, safe='')}/issues/{index}",
             json_body=payload,
-            correlation_id=str(
-                self.audit.log_tool_invocation(tool_name="update_issue", result_status="pending")
-            ),
+            correlation_id=correlation_id,
         )
         return result if isinstance(result, dict) else {}
 

src/aegis_gitea_mcp/mcp_protocol.py

@@ -464,6 +464,10 @@ AVAILABLE_TOOLS: list[MCPTool] = [
                 "body": {"type": "string", "default": ""},
                 "labels": {"type": "array", "items": {"type": "string"}, "default": []},
                 "assignees": {"type": "array", "items": {"type": "string"}, "default": []},
+                "milestone": {
+                    "type": ["integer", "string"],
+                    "description": "Milestone id or title to assign the issue to",
+                },
             },
             "required": ["owner", "repo", "title"],
             "additionalProperties": False,
@@ -472,7 +476,7 @@ AVAILABLE_TOOLS: list[MCPTool] = [
     ),
     _tool(
         "update_issue",
-        "Update issue title/body/state (write-mode only).",
+        "Update issue title/body/state/milestone (write-mode only).",
         {
             "type": "object",
             "properties": {
@@ -482,6 +486,10 @@ AVAILABLE_TOOLS: list[MCPTool] = [
                 "title": {"type": "string"},
                 "body": {"type": "string"},
                 "state": {"type": "string", "enum": ["open", "closed"]},
+                "milestone": {
+                    "type": ["integer", "string"],
+                    "description": "Milestone id or title to assign; 0 clears the milestone",
+                },
             },
             "required": ["owner", "repo", "issue_number"],
             "additionalProperties": False,

src/aegis_gitea_mcp/tools/arguments.py

@@ -4,7 +4,14 @@ from __future__ import annotations
 
 from typing import Annotated, Literal
 
-from pydantic import AfterValidator, BaseModel, ConfigDict, Field, model_validator
+from pydantic import (
+    AfterValidator,
+    BaseModel,
+    BeforeValidator,
+    ConfigDict,
+    Field,
+    model_validator,
+)
 
 _REPO_PART_PATTERN = r"^[A-Za-z0-9._-]{1,100}$"
 
@@ -45,6 +52,33 @@ def _validate_git_ref(value: str) -> str:
 GitRef = Annotated[str, AfterValidator(_validate_git_ref)]
 
 
+def _validate_milestone(value: object) -> int | str:
+    """Validate a milestone reference supplied as a numeric id or a title.
+
+    An integer is treated as a milestone id (``0`` clears the milestone on
+    update); a string is treated as a milestone title to resolve. Runs as a
+    ``BeforeValidator`` so ``bool`` (a subclass of ``int`` that Pydantic would
+    otherwise coerce to ``1``/``0``) is rejected on the raw input.
+    """
+    if isinstance(value, bool):
+        raise ValueError("milestone must be a milestone id or title")
+    if isinstance(value, int):
+        if value < 0:
+            raise ValueError("milestone id must be >= 0")
+        return value
+    if isinstance(value, str):
+        title = value.strip()
+        if not title:
+            raise ValueError("milestone title must not be empty")
+        if len(title) > 256:
+            raise ValueError("milestone title must not exceed 256 characters")
+        return title
+    raise ValueError("milestone must be a milestone id or title")
+
+
+MilestoneRef = Annotated[int | str, BeforeValidator(_validate_milestone)]
+
+
 class StrictBaseModel(BaseModel):
     """Strict model base that rejects unexpected fields."""
 
@@ -174,6 +208,9 @@ class CreateIssueArgs(RepositoryArgs):
     body: str = Field(default="", max_length=20_000)
     labels: list[str] = Field(default_factory=list, max_length=20)
     assignees: list[str] = Field(default_factory=list, max_length=20)
+    milestone: MilestoneRef | None = Field(
+        default=None, description="Milestone id or title to assign the issue to"
+    )
 
 
 class UpdateIssueArgs(RepositoryArgs):
@@ -183,12 +220,20 @@ class UpdateIssueArgs(RepositoryArgs):
     title: str | None = Field(default=None, min_length=1, max_length=256)
     body: str | None = Field(default=None, max_length=20_000)
     state: Literal["open", "closed"] | None = Field(default=None)
+    milestone: MilestoneRef | None = Field(
+        default=None, description="Milestone id or title to assign; 0 clears the milestone"
+    )
 
     @model_validator(mode="after")
     def require_change(self) -> UpdateIssueArgs:
         """Require at least one mutable field in update payload."""
-        if self.title is None and self.body is None and self.state is None:
-            raise ValueError("At least one of title, body, or state must be provided")
+        if (
+            self.title is None
+            and self.body is None
+            and self.state is None
+            and self.milestone is None
+        ):
+            raise ValueError("At least one of title, body, state, or milestone must be provided")
         return self
 
 

src/aegis_gitea_mcp/tools/write_tools.py

@@ -30,6 +30,14 @@ from aegis_gitea_mcp.tools.arguments import (
 )
 
 
+def _milestone_title(issue: dict[str, Any]) -> str:
+    """Extract the milestone title from an issue payload, or '' if unset."""
+    milestone = issue.get("milestone")
+    if isinstance(milestone, dict):
+        return limit_text(str(milestone.get("title", "")))
+    return ""
+
+
 async def create_label_tool(gitea: GiteaClient, arguments: dict[str, Any]) -> dict[str, Any]:
     """Create a repository label in write mode."""
     parsed = CreateLabelArgs.model_validate(arguments)
@@ -119,11 +127,13 @@ async def create_issue_tool(gitea: GiteaClient, arguments: dict[str, Any]) -> di
             body=parsed.body,
             labels=parsed.labels,
             assignees=parsed.assignees,
+            milestone=parsed.milestone,
         )
         return {
             "number": issue.get("number", 0),
             "title": limit_text(str(issue.get("title", ""))),
             "state": issue.get("state", ""),
+            "milestone": _milestone_title(issue),
             "url": issue.get("html_url", ""),
         }
     except (GiteaAuthenticationError, GiteaAuthorizationError):
@@ -145,11 +155,13 @@ async def update_issue_tool(gitea: GiteaClient, arguments: dict[str, Any]) -> di
             title=parsed.title,
             body=parsed.body,
             state=parsed.state,
+            milestone=parsed.milestone,
         )
         return {
             "number": issue.get("number", parsed.issue_number),
             "title": limit_text(str(issue.get("title", ""))),
             "state": issue.get("state", ""),
+            "milestone": _milestone_title(issue),
             "url": issue.get("html_url", ""),
         }
     except (GiteaAuthenticationError, GiteaAuthorizationError):