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.
npx agentmods add skills/neverinfamous/memory-journal-mcp/durable-objectsnpx skills add neverinfamous/memory-journal-mcp --skill durable-objectsgit clone --depth 1 https://github.com/neverinfamous/memory-journal-mcpWhat 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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00063 | $0.01332 |
| Opus 5 | $0.00032 | $0.00666 |
| Sonnet 5 | $0.00013 | $0.00266 |
| Haiku 4.5 | $0.00006 | $0.00133 |
Grade A, and why
durable-objects scanned grade A with 1 finding 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 2d ago.
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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
async fetch(request: Request, env: Env): Promise<Response> { This is a copy
88% identical to durable-objects — 117 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 168 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Durable Objects
Build stateful, coordinated applications on Cloudflare's edge using Durable Objects.
Retrieval-First Development
Prefer retrieval from official docs over pre-training for Durable Objects tasks.
| Resource | URL |
|---|---|
| Docs | https://developers.cloudflare.com/durable-objects/ |
| API Reference | https://developers.cloudflare.com/durable-objects/api/ |
| Best Practices | https://developers.cloudflare.com/durable-objects/best-practices/ |
| Examples | https://developers.cloudflare.com/durable-objects/examples/ |
Fetch the relevant doc page when implementing features.
When to Use
- Creating new Durable Object classes for stateful coordination
- Implementing RPC methods, alarms, or WebSocket handlers
- Reviewing existing DO code for best practices
- Configuring wrangler.jsonc/toml for DO bindings and migrations
- Writing tests with
@cloudflare/vitest-pool-workers - Designing sharding strategies and parent-child relationships
Reference Documentation
./references/rules.md- Core rules, storage, concurrency, RPC, alarms./references/testing.md- Vitest setup, unit/integration tests, alarm testing./references/workers.md- Workers handlers, types, wrangler config, observability
Search: blockConcurrencyWhile, idFromName, getByName, setAlarm, sql.exec
Core Principles
Use Durable Objects For
| Need | Example |
|---|---|
| Coordination | Chat rooms, multiplayer games, collaborative docs |
| Strong consistency | Inventory, booking systems, turn-based games |
| Per-entity storage | Multi-tenant SaaS, per-user data |
| Persistent connections | WebSockets, real-time notifications |
| Scheduled work per entity | Subscription renewals, game timeouts |
What ships with it
4 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 2d ago First seen · 168 lines · 63 tokens per session scan A b090c3c454f6
durable-objects is a skill published in the GitHub repository neverinfamous/memory-journal-mcp (20 stars, last pushed 1mo ago), licensed MIT. It adds 63 tokens to every session and 1,332 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). It is 88% identical to durable-objects, differing in 117 lines, and is treated as a copy.
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