Durable Objects · Product category
Browse cases and guides explicitly labeled Durable Objects.
29 matching items
Cases · 8
babynarc: a Durable Objects alarm loop and a surprise bill that grew from $300 to $500.
@babynarc says an alarm loop in an old Durable Object he thought was inactive left him badly burned: he watched a surprise $300 bill grow to $500 even after killing it. Replying to Cloudflare's Dane Knecht and Kenton Varda, he suggests prepending budget-alert details to every `cf` result by default.
Reported amount · USD
$500
shmily7: a Durable Object alarm loop and a reported US$10,811.41 bill.
@shmily7 reports a Durable Object alarm loop in an unused test project, then says he paid the full US$10,811.41 bill to avoid service suspension. Cloudflare’s Ashley Peacock publicly says he is looking into it internally and will follow up. Cloudflare’s Dane Knecht later replies that he escalated it too. On October 9 the author declares the case closed: he reports that, with Ashley Peacock’s help, Cloudflare decided to refund the charges incurred during the bug in full, with the money still to arrive, and posts the support ticket reply he received.
Reported amount · USD
$10,811.41
A simulation game, a reported $4,483.74 in Durable Object reads.
Jonathan Mann (@songadaymann) reports spending $4,483.74 on Durable Object reads while building a simulation game. Rita Kozlov replies, “let us see what we can do”; Mann thanks her, and she replies that she is DMing him for details.
Reported amount · USD
$4,483.74
A development app, a reported $655.83 Durable Object alarm bill.
@q_huy_ngo reports a $655.83 bill and roughly 700 million interactions from a faulty alarm in an app with no users. CloudflareHelp says it will review the support case and reply in the ticket.
Reported amount · USD
$655.83
Standard Agents: two loops, a reported $8,846 bill.
Justin Schroeder and Boyd describe the same Standard Agents incident: two Durable Objects ran unbounded loops. Justin reports an $8,846 bill and a later bill adjustment.
Reported amount · USD
$8,846
Durable Objects: a hackathon evaluation program leads to a billing complaint.
@nukonuko reports an unexpectedly large Cloudflare invoice, stops the suspected Durable Objects usage and asks support for a refund. Later posts link the incident to a hackathon evaluation program and say income will go toward the bill.
Reported amount · USD
Not disclosed
Will Moss: an alarm loop, 20 trillion Durable Object reads and a reported $34,895 invoice.
@itswillmoss reports 20,213,871,155,804 Durable Object reads, a dashboard mismatch and lost project access. He attributes the loop to health checks waking onStart and repeatedly setting an alarm. The X thread estimates the cost above $30,000; a same-day Hacker News post by thewillmoss describing the same alarm loop reports a $34,895 invoice and a support case awaiting a billing response.
Reported amount · USD
$34,895
Steven Menke: an Agents SDK bug and a reported $1,700 Durable Objects invoice.
Steven Menke (@Galorious_) reports that runaway Durable Objects caused by an Agents SDK bug produced a $1,700 invoice in three days, citing one trillion SQLite reads (a later post says writes). He says his support ticket, even after a maintainer escalated it, received no reply for months.
Reported amount · USD
$1,700
Guides · 21
Layered defenses after a Durable Object alarm loop
星星之火可以燎原 (@fireandstart) reads a public Durable Object alarm-loop recap and argues for layered defenses rather than relying on being more careful next time.
How I keep Cloudflare under $5: where surprise bills come from
Ashish Sharma (@sarmaasis) runs several sites on the $5 Workers Paid plan and lists, product by product, the usage patterns he says quietly run up a Cloudflare bill, ending with a 12-item checklist.
Put the spending ceiling into AI-generated code
Prasenjit Sarkar (@stretchcloud) uses the Durable Objects alarm loop to argue that alarms bill without traffic, that a single console cap cannot cover multi-vendor agent work, and that generated code needs execution quotas, idempotency checks and a kill switch.
Idle projects can still bill: check background tasks and storage
@An_yhl reads @shmily7’s follow-up as a reason to audit abandoned AI projects: check scheduled background work and storage reads and writes, stop what is unused instead of just closing the page, and turn on alerts knowing they will not stop anything.
Removing unneeded Durable Objects from MCP servers on Workers
Justin (@interjc) describes moving read-only MCP servers from McpAgent, which starts a Durable Object per session, to stateless createMcpHandler, and shares a prompt for auditing Workers bindings and runaway usage patterns.
Cloudflare costs $5 a month, but the bill is not capped
不追高 (@Ariella1213) writes an X article explaining that Workers Paid’s $5 is a minimum, that per-product limits and budget alerts do not cap the account bill, and how denial-of-wallet requests, write amplification, delayed stops and background retries add cost.
Introducing on-demand profiling: Cloudflare production examples
Dominik Picheta introduces on-demand CPU and memory profiling for Workers and Durable Objects, sharing Cloudflare examples of removing duplicate work and unnecessary allocation paths.
Why hard spending caps take time: Ashley Peacock on billing latency
Ashley Peacock (@ashleypeacock), who works on Durable Objects at Cloudflare, explains from experience why near-real-time spending caps are hard to build, says hard billing caps are coming soon, and suggests budget alerts plus issue alerts in the meantime.
A prompt to set up Cloudflare budget and usage alerts
Merill Fernando (@merill) shares a prompt that asks a coding agent to install Cloudflare’s CLI, check for a billing budget alert and add usage alerts based on last month’s usage, and lists what it set up for him.
Check getAlarm() first and keep preview off real Durable Objects
@graycoin retells the Durable Object alarm loop shared by @shmily7 and draws three habits: check getAlarm() before setAlarm(), do not bind preview environments to real Durable Objects, and reread AI-generated storage and scheduling code.
Lanshu: an AI-assisted Cloudflare billing risk checklist
Lanshu (@LufzzLiz) shares a six-step prompt for checking account ownership, usage, runaway consumption and budget alerts. Replies add alarm logging, email delivery checks and separate notifications.
After a $10,000 loop bill: budget alerts and a cost-audit prompt for vibe-coded projects
铁柱AGI (@cgnot996) writes an X article that walks through creating a Cloudflare budget alert, explains why it is only a notice, lists cost-amplifying code patterns, and gives a read-only audit prompt and steps for when a bill has already spiked.
Four layers of cost protection for small Cloudflare projects
David Z (@davezfr) writes an X article for vibe coders on budget alerts, stop conditions for paid paths, automatic pausing, and letting a personal agent verify and pause.
Durable Object alarm rules for agents.md
Viking (@vikingmute) shares the AI-generated Durable Object alarm rules he keeps in agents.md and suggests having another model review changes.
Cloudflare billing pitfalls thread
The author organizes Cloudflare billing risks by product and shares experience with budget alert emails.
cloudflare-cost-guard
Louis Cai’s open-source rules and TypeScript base class for keeping Durable Object alarms and Worker schedulers from runaway loops.
Durable Objects alarms
Cloudflare documents how Durable Object alarms are scheduled, retried, and deleted.
Optimize costs
Cloudflare lists ways to find and reduce usage-based charges by product.
Production profiling for Workers and Durable Objects: operation guide
Cloudflare explains how to locate expensive functions and memory allocations in deployed Workers and Durable Objects using on-demand profiles and flamegraphs.
WebSocket hibernation with Durable Objects
Cloudflare shows how Durable Objects hibernate WebSocket connections while idle.
Cloudflare Medivh: a self-hosted near-real-time bill estimator
An open-source, self-hosted monitor that adds today’s estimated usage cost to Cloudflare’s daily-updated billable usage, sends summaries, and calls a webhook when the current cycle crosses a budget.