domain-patterns

A reference document showing Go code patterns for defining data types in a project's internal domain layer—the part that represents the application's core data.

In plain words
What is it for?
Use it when creating or reviewing domain types in internal/domain/.
Why use it?
It reduces guesswork when adding new resources, nested data, or query parameters to a Nylas-related Go project.

Command for Claude Code

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add commands/nylas/cli/domain-patterns
Clone the repo
git clone --depth 1 https://github.com/nylas/cli

Made for: Claude Code.

Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 713 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.00713
Opus 5 $0.00000 $0.00357
Sonnet 5 $0.00000 $0.00143
Haiku 4.5 $0.00000 $0.00071

Measured yesterday against content hash 0d9d75f4a46d, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

domain-patterns scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/commands/add-command/references/domain-patterns.md · 138 lines

How it starts

The opening of the file, as written. The whole thing — 138 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Domain Type Patterns

Reference patterns for creating domain types in internal/domain/.


Basic Resource Type

package domain

// Resource represents a resource from Nylas API.
type Resource struct {
    ID        string `json:"id"`
    GrantID   string `json:"grant_id"`
    Object    string `json:"object,omitempty"`
    Name      string `json:"name,omitempty"`
    CreatedAt int64  `json:"created_at,omitempty"`
    UpdatedAt int64  `json:"updated_at,omitempty"`
}

Resource with Nested Types

// Contact with nested email/phone types
type Contact struct {
    ID           string         `json:"id"`
    GrantID      string         `json:"grant_id"`
    GivenName    string         `json:"given_name,omitempty"`
    Surname      string         `json:"surname,omitempty"`
    Emails       []ContactEmail `json:"emails,omitempty"`
    PhoneNumbers []ContactPhone `json:"phone_numbers,omitempty"`
}

type ContactEmail struct {
    Email string `json:"email"`
    Type  string `json:"type,omitempty"` // home, work, school, other
}

type ContactPhone struct {
    Number string `json:"number"`
    Type   string `json:"type,omitempty"`
}

Query Parameters Type

// ResourceQueryParams defines query parameters for listing resources.
type ResourceQueryParams struct {
    Limit     int    `json:"limit,omitempty"`
    PageToken string `json:"page_token,omitempty"`
    // Add resource-specific filters
    Status    string `json:"status,omitempty"`
    Search    string `json:"search,omitempty"`
}

List Response Type

// ResourceListResponse represents paginated list response.
type ResourceListResponse struct {
    Data          []Resource `json:"data"`
    NextCursor    string     `json:"next_cursor,omitempty"`
    RequestID     string     `json:"request_id,omitempty"`
}

Helper Methods

// DisplayName returns a formatted display name.
func (r Resource) DisplayName() string {
    if r.Name != "" {
        return r.Name
    }
    return r.ID
}

// PrimaryEmail returns the primary email address.
func (c Contact) PrimaryEmail() string {
    for _, e := range c.Emails {
        if e.Type == "primary" || e.Type == "work" {
            return e.Email
        }
    }
    if len(c.Emails) > 0 {
        return c.Emails[0].Email
    }
    return ""
}

Read the full file on GitHub · 138 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 138 lines · 0 tokens per session scan A 0d9d75f4a46d

Subscribe to this mod's changes

domain-patterns is a command published in the GitHub repository nylas/cli (68 stars, last pushed 13d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 713 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.