MCP: name-based resolution for Projects fields

README.md

@@ -1068,7 +1068,8 @@ The following sets of tools are available:
   - **Required OAuth Scopes**: `read:project`
   - **Accepted OAuth Scopes**: `project`, `read:project`
   - `field_id`: The field's ID. Required for 'get_project_field' method. (number, optional)
-  - `fields`: Specific list of field IDs to include in the response when getting a project item (e.g. ["102589", "985201", "169875"]). If not provided, only the title field is included. Only used for 'get_project_item' method. (string[], optional)
+  - `field_names`: Specific list of field names to include in the response when getting a project item (e.g. ["Status", "Priority"]). Resolved server-side to field IDs — pass this instead of 'fields' when you only know the human-readable names. Only used for 'get_project_item' method. (string[], optional)
+  - `fields`: Specific list of field IDs to include in the response when getting a project item (e.g. ["102589", "985201", "169875"]). If neither 'fields' nor 'field_names' is provided, only the title field is included. Only used for 'get_project_item' method. (string[], optional)
   - `item_id`: The item's ID. Required for 'get_project_item' method. (number, optional)
   - `method`: The method to execute (string, required)
   - `owner`: The owner (user or organization login). The name is not case sensitive. (string, optional)
@@ -1081,7 +1082,8 @@ The following sets of tools are available:
   - **Accepted OAuth Scopes**: `project`, `read:project`
   - `after`: Forward pagination cursor from previous pageInfo.nextCursor. (string, optional)
   - `before`: Backward pagination cursor from previous pageInfo.prevCursor (rare). (string, optional)
-  - `fields`: Field IDs to include when listing project items (e.g. ["102589", "985201"]). CRITICAL: Always provide to get field values. Without this, only titles returned. Only used for 'list_project_items' method. (string[], optional)
+  - `field_names`: Field names to include when listing project items (e.g. ["Status", "Priority"]). Resolved server-side to field IDs — pass this instead of 'fields' when you only know the human-readable names. Names that fail to resolve return a structured error. Only used for 'list_project_items' method. (string[], optional)
+  - `fields`: Field IDs to include when listing project items (e.g. ["102589", "985201"]). CRITICAL: Always provide to get field values. Without this (and without 'field_names'), only titles returned. Only used for 'list_project_items' method. (string[], optional)
   - `method`: The action to perform (string, required)
   - `owner`: The owner (user or organization login). The name is not case sensitive. (string, required)
   - `owner_type`: Owner type (user or org). If not provided, will automatically try both. (string, optional)
@@ -1093,10 +1095,10 @@ The following sets of tools are available:
   - **Required OAuth Scopes**: `project`
   - `body`: The body of the status update (markdown). Used for 'create_project_status_update' method. (string, optional)
   - `field_name`: The name of the iteration field (e.g. 'Sprint'). Required for 'create_iteration_field' method. (string, optional)
-  - `issue_number`: The issue number (use when item_type is 'issue' for 'add_project_item' method). Provide either issue_number or pull_request_number. (number, optional)
-  - `item_id`: The project item ID. Required for 'update_project_item' and 'delete_project_item' methods. (number, optional)
-  - `item_owner`: The owner (user or organization) of the repository containing the issue or pull request. Required for 'add_project_item' method. (string, optional)
-  - `item_repo`: The name of the repository containing the issue or pull request. Required for 'add_project_item' method. (string, optional)
+  - `issue_number`: The issue number. Required for 'add_project_item' when item_type is 'issue'. Also accepted by 'update_project_item' to resolve the item by issue number (combine with item_owner and item_repo). (number, optional)
+  - `item_id`: The project item ID. Required for 'delete_project_item'. For 'update_project_item', provide either item_id, or (item_owner + item_repo + issue_number) to resolve the item by issue. (number, optional)
+  - `item_owner`: The owner (user or organization) of the repository containing the issue or pull request. Required for 'add_project_item' method. Also accepted by 'update_project_item' when resolving the item by issue number. (string, optional)
+  - `item_repo`: The name of the repository containing the issue or pull request. Required for 'add_project_item' method. Also accepted by 'update_project_item' when resolving the item by issue number. (string, optional)
   - `item_type`: The item's type, either issue or pull_request. Required for 'add_project_item' method. (string, optional)
   - `iteration_duration`: Duration in days for iterations of the field (e.g. 7 for weekly, 14 for bi-weekly). Required for 'create_iteration_field' method. (number, optional)
   - `iterations`: Custom iterations for 'create_iteration_field' method. Only set this when you need iterations with varying durations, breaks between them, or specific titles. Otherwise omit it: GitHub auto-creates three iterations of 'iteration_duration' days starting on 'start_date', which is the right choice for most cases. (object[], optional)
@@ -1109,7 +1111,7 @@ The following sets of tools are available:
   - `status`: The status of the project. Used for 'create_project_status_update' method. (string, optional)
   - `target_date`: The target date of the status update in YYYY-MM-DD format. Used for 'create_project_status_update' method. (string, optional)
   - `title`: The project title. Required for 'create_project' method. (string, optional)
-  - `updated_field`: Object consisting of the ID of the project field to update and the new value for the field. To clear the field, set value to null. Example: {"id": 123456, "value": "New Value"}. Required for 'update_project_item' method. (object, optional)
+  - `updated_field`: Object describing the field to update and its new value. Required for 'update_project_item'. Two shapes are accepted: (1) by ID — {"id": 123456, "value": "..."}; (2) by name — {"name": "Status", "value": "In Progress"}. For single-select fields, option-name resolution requires the by-name shape; on the by-ID shape, pass the option ID. Set value to null to clear the field. (object, optional)
 
 </details>
 

pkg/errors/error.go

@@ -2,6 +2,7 @@ package errors
 
 import (
 	"context"
+	"encoding/json"
 	stderrors "errors"
 	"fmt"
 	"net/http"
@@ -218,3 +219,48 @@ func NewGitHubAPIStatusErrorResponse(ctx context.Context, message string, resp *
 	err := fmt.Errorf("unexpected status %d: %s", resp.StatusCode, string(body))
 	return NewGitHubAPIErrorResponse(ctx, message, resp, err)
 }
+
+// StructuredResolutionError is a machine-readable error returned by name-resolution
+// helpers (e.g. resolving a project field or single-select option by name). Agents
+// can parse the JSON body to self-correct without re-prompting.
+//
+// Kind values:
+//   - "field_not_found"      — no project field matches the supplied name
+//   - "field_ambiguous"      — more than one project field shares the supplied name
+//   - "option_not_found"     — no option on the resolved single-select field matches
+//   - "option_ambiguous"     — duplicate option names on the resolved field
+//   - "item_not_in_project"  — the issue/PR exists but is not an item on the project
+//   - "wrong_field_type"     — the named field is not the data type the caller expected
+type StructuredResolutionError struct {
+	Kind       string `json:"error"`
+	Name       string `json:"name,omitempty"`
+	Field      string `json:"field,omitempty"`
+	Candidates []any  `json:"candidates,omitempty"`
+	Hint       string `json:"hint,omitempty"`
+}
+
+// Error implements the error interface; the message is the JSON body so that the
+// downstream tool result also carries the structured payload as plain text.
+func (e *StructuredResolutionError) Error() string {
+	b, err := json.Marshal(e)
+	if err != nil {
+		return fmt.Sprintf(`{"error":%q,"name":%q}`, e.Kind, e.Name)
+	}
+	return string(b)
+}
+
+// NewStructuredResolutionError constructs a StructuredResolutionError.
+func NewStructuredResolutionError(kind, name, hint string, candidates []any) *StructuredResolutionError {
+	return &StructuredResolutionError{
+		Kind:       kind,
+		Name:       name,
+		Hint:       hint,
+		Candidates: candidates,
+	}
+}
+
+// NewStructuredResolutionErrorResponse returns an mcp.CallToolResult whose text body
+// is the JSON-serialised StructuredResolutionError, suitable for agent self-correction.
+func NewStructuredResolutionErrorResponse(err *StructuredResolutionError) *mcp.CallToolResult {
+	return utils.NewToolResultError(err.Error())
+}

pkg/github/__toolsnaps__/projects_get.snap

@@ -10,8 +10,15 @@
         "description": "The field's ID. Required for 'get_project_field' method.",
         "type": "number"
       },
+      "field_names": {
+        "description": "Specific list of field names to include in the response when getting a project item (e.g. [\"Status\", \"Priority\"]). Resolved server-side to field IDs — pass this instead of 'fields' when you only know the human-readable names. Only used for 'get_project_item' method.",
+        "items": {
+          "type": "string"
+        },
+        "type": "array"
+      },
       "fields": {
-        "description": "Specific list of field IDs to include in the response when getting a project item (e.g. [\"102589\", \"985201\", \"169875\"]). If not provided, only the title field is included. Only used for 'get_project_item' method.",
+        "description": "Specific list of field IDs to include in the response when getting a project item (e.g. [\"102589\", \"985201\", \"169875\"]). If neither 'fields' nor 'field_names' is provided, only the title field is included. Only used for 'get_project_item' method.",
         "items": {
           "type": "string"
         },

pkg/github/__toolsnaps__/projects_list.snap

@@ -14,8 +14,15 @@
         "description": "Backward pagination cursor from previous pageInfo.prevCursor (rare).",
         "type": "string"
       },
+      "field_names": {
+        "description": "Field names to include when listing project items (e.g. [\"Status\", \"Priority\"]). Resolved server-side to field IDs — pass this instead of 'fields' when you only know the human-readable names. Names that fail to resolve return a structured error. Only used for 'list_project_items' method.",
+        "items": {
+          "type": "string"
+        },
+        "type": "array"
+      },
       "fields": {
-        "description": "Field IDs to include when listing project items (e.g. [\"102589\", \"985201\"]). CRITICAL: Always provide to get field values. Without this, only titles returned. Only used for 'list_project_items' method.",
+        "description": "Field IDs to include when listing project items (e.g. [\"102589\", \"985201\"]). CRITICAL: Always provide to get field values. Without this (and without 'field_names'), only titles returned. Only used for 'list_project_items' method.",
         "items": {
           "type": "string"
         },

pkg/github/__toolsnaps__/projects_write.snap

@@ -15,19 +15,19 @@
         "type": "string"
       },
       "issue_number": {
-        "description": "The issue number (use when item_type is 'issue' for 'add_project_item' method). Provide either issue_number or pull_request_number.",
+        "description": "The issue number. Required for 'add_project_item' when item_type is 'issue'. Also accepted by 'update_project_item' to resolve the item by issue number (combine with item_owner and item_repo).",
         "type": "number"
       },
       "item_id": {
-        "description": "The project item ID. Required for 'update_project_item' and 'delete_project_item' methods.",
+        "description": "The project item ID. Required for 'delete_project_item'. For 'update_project_item', provide either item_id, or (item_owner + item_repo + issue_number) to resolve the item by issue.",
         "type": "number"
       },
       "item_owner": {
-        "description": "The owner (user or organization) of the repository containing the issue or pull request. Required for 'add_project_item' method.",
+        "description": "The owner (user or organization) of the repository containing the issue or pull request. Required for 'add_project_item' method. Also accepted by 'update_project_item' when resolving the item by issue number.",
         "type": "string"
       },
       "item_repo": {
-        "description": "The name of the repository containing the issue or pull request. Required for 'add_project_item' method.",
+        "description": "The name of the repository containing the issue or pull request. Required for 'add_project_item' method. Also accepted by 'update_project_item' when resolving the item by issue number.",
         "type": "string"
       },
       "item_type": {
@@ -125,7 +125,7 @@
         "type": "string"
       },
       "updated_field": {
-        "description": "Object consisting of the ID of the project field to update and the new value for the field. To clear the field, set value to null. Example: {\"id\": 123456, \"value\": \"New Value\"}. Required for 'update_project_item' method.",
+        "description": "Object describing the field to update and its new value. Required for 'update_project_item'. Two shapes are accepted: (1) by ID — {\"id\": 123456, \"value\": \"...\"}; (2) by name — {\"name\": \"Status\", \"value\": \"In Progress\"}. For single-select fields, option-name resolution requires the by-name shape; on the by-ID shape, pass the option ID. Set value to null to clear the field.",
         "type": "object"
       }
     },