github/github-mcp-server · error

failed to update issue with agent assignment: %w

Error message

failed to update issue with agent assignment: %w

What it means

The GraphQL updateIssue mutation carrying AssigneeIDs (the copilot-swe-agent bot) and the AgentAssignment input failed during assign_copilot_to_issue. The mutation runs on a context tagged with the issues_copilot_assignment_api_support feature so GitHub can gate the private AgentAssignment field; GitHub rejects it when the feature is unavailable, Copilot is not enabled, or the token lacks permission. This is a server-side rejection of the assignment, after the suggested-actor lookup already succeeded.

Source

Thrown at pkg/github/copilot.go:360

			// Add the GraphQL-Features header for the agent assignment API
			// The header will be read by the HTTP transport if it's configured to do so
			ctxWithFeatures := ghcontext.WithGraphQLFeatures(ctx, "issues_copilot_assignment_api_support")

			// Capture the time before assignment to filter out older PRs during polling
			assignmentTime := time.Now().UTC()

			if err := client.Mutate(
				ctxWithFeatures,
				&updateIssueMutation,
				UpdateIssueInput{
					ID:              getIssueQuery.Repository.Issue.ID,
					AssigneeIDs:     actorIDs,
					AgentAssignment: agentAssignment,
				},
				nil,
			); err != nil {
				return nil, nil, fmt.Errorf("failed to update issue with agent assignment: %w", err)
			}

			// Poll for a linked PR created by Copilot after the assignment
			pollConfig := getPollConfig(ctx)

			// Get progress token from request for sending progress notifications
			progressToken := request.Params.GetProgressToken()

			// Send initial progress notification that assignment succeeded and polling is starting
			if progressToken != nil && request.Session != nil && pollConfig.MaxAttempts > 0 {
				_ = request.Session.NotifyProgress(ctx, &mcp.ProgressNotificationParams{
					ProgressToken: progressToken,
					Progress:      0,
					Total:         float64(pollConfig.MaxAttempts),
					Message:       "Copilot assigned to issue, waiting for PR creation...",
				})
			}

View on GitHub (pinned to 0ea1f775a7)

Solutions

1. Enable the Copilot coding agent for the repository/org (docs.github.com Copilot cloud-agent) and retry
2. Use a PAT or GitHub App token with write access to issues in that repository
3. Check the wrapped GraphQL error message for FORBIDDEN/NOT_FOUND to distinguish permissions from feature unavailability
4. Verify the issue is open and the repo is not archived, then retry

Example fix

// before
if err := client.Mutate(ctxWithFeatures, &updateIssueMutation, input, nil); err != nil {
	return nil, nil, fmt.Errorf("failed to update issue with agent assignment: %w", err)
}

// after — classify the GraphQL rejection for the caller
if err := client.Mutate(ctxWithFeatures, &updateIssueMutation, input, nil); err != nil {
	msg := err.Error()
	if strings.Contains(msg, "FORBIDDEN") {
		return utils.NewToolResultError("copilot assignment denied: enable the Copilot coding agent and use a token with issue write access"), nil, nil
	}
	return nil, nil, fmt.Errorf("failed to update issue with agent assignment: %w", err)
}

// pre-flight: confirm Copilot agent availability before assigning
copilotActor, err := findCopilotSuggestedActor(ctx, client, owner, repo)
if err != nil {
	return err // suggested-actors query itself failed
}
if copilotActor == nil {
	return errors.New("copilot is not available as an assignee for this repo — enable the Copilot coding agent first")
}

if err := client.Mutate(ctxWithFeatures, &updateIssueMutation, input, nil); err != nil {
	msg := err.Error()
	switch {
	case strings.Contains(msg, "FORBIDDEN"):
		// permissions/Copilot disabled — surface actionable guidance, no retry
	case strings.Contains(msg, "NOT_FOUND"):
		// stale issue/repo — refetch and optionally retry once
	default:
		return fmt.Errorf("failed to update issue with agent assignment: %w", err)
	}
}

When it happens

Trigger: Calling assign_copilot_to_issue on a repo/org where the Copilot coding agent (cloud agent) is disabled, with a token lacking write/issue-assign permission, on a GitHub instance whose schema does not accept the AgentAssignment input (feature flag not honored), or when the issue cannot accept agent assignment (locked, archived repo).

Common situations: Org policy disabling Copilot coding agent, fine-grained PAT without Issues:write, GHES version predating agent assignment API, race where the issue was closed between lookup and mutation.

Related errors

• failed to get GitHub client: %w
• failed to get issue ID: %w
• perPage value %d exceeds maximum of 100
• perPage value %d cannot be negative
• mutation_unconfirmed

AI-assisted analysis of github/github-mcp-server@0ea1f775a7 (2026-08-15). Data as JSON: /api/errors/5d56b437096708ea. Report an issue: GitHub.