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use-cases / replay-this-mornings-incident / hero

PIPE · INCIDENT REPLAY

Replay this morning's incident to the whole team

It's 2pm. The 7am incident is being post-mortemed. Six engineers want to walk through the exact log sequence the on-call SRE saw at the time. You stream the snapshot through one Hoody Pipe URL with ?n=8. Everyone watches the cascade fire on their own terminal at the same moment — no screenshots, no scrolling out of sync, no Zoom recording.

Read the pipe API

incident-2026-05-04 · 07:00 – 08:00

07:00

07:15

07:23

07:30

07:45

08:00

INCIDENT START

07:23:14 UTC

alex

07:23:14INFOPOST /v1/checkout u_28f

07:23:15WARNstripe latency 2.4s

07:23:16ERR 500 stripe timeout

07:23:17···auto-rollback armed

ben

07:23:14INFOPOST /v1/checkout u_28f

07:23:15WARNstripe latency 2.4s

07:23:16ERR 500 stripe timeout

07:23:17···auto-rollback armed

chen

07:23:14INFOPOST /v1/checkout u_28f

07:23:15WARNstripe latency 2.4s

07:23:16ERR 500 stripe timeout

07:23:17···auto-rollback armed

dani

07:23:14INFOPOST /v1/checkout u_28f

07:23:15WARNstripe latency 2.4s

07:23:16ERR 500 stripe timeout

07:23:17···auto-rollback armed

ev

07:23:14INFOPOST /v1/checkout u_28f

07:23:15WARNstripe latency 2.4s

07:23:16ERR 500 stripe timeout

07:23:17···auto-rollback armed

fox

07:23:14INFOPOST /v1/checkout u_28f

07:23:15WARNstripe latency 2.4s

07:23:16ERR 500 stripe timeout

07:23:17···auto-rollback armed

playing · lockstepPOS1×

use-cases / replay-this-mornings-incident / mechanism

One snapshot. One pipe. Six terminals in lockstep.

Take the morning's incident-time log file from your hoody-files snapshot. Stream it through a Hoody Pipe path with ?n=8. Eight engineers curl the same path. The pipe waits until everyone is connected, then the bytes move through once at the rate you set — every reader sees the same line at the same moment.

post-mortem.host · sender

PUT · replay

# The 7am incident is captured in incident-2026-05-04.log
# (snapshotted from /var/log/app at 07:25 by the on-call SRE).
# Replay it through a pipe path with ?n=8 — the server waits
# until eight readers connect, then the bytes move through once.
# pv -L 50k rate-limits the replay to a readable 50KB/s.

cat incident-2026-05-04.log \
  | pv -L 50k \
  | curl -T - \
      "https://prod-pipe.containers.hoody.com/api/v1/pipe/replay?n=8"

# [INFO] Waiting for 8 receiver(s) to connect...
# [INFO] Streaming to 8 receiver(s) at 50.0 KB/s

all 8 readers connected · pipe holds nothing · bytes move through once

alex / ben / chen / dani / ev / fox / two more · readers

GET · lockstep

# Each engineer in the post-mortem call runs the same line.
# They block until everyone has joined, then the cascade scrolls
# past their terminal at the exact rate the SRE saw at 07:23.

curl "https://prod-pipe.containers.hoody.com/api/v1/pipe/replay?n=8"

# 07:23:14 INFO POST /v1/checkout u_28f
# 07:23:15 WARN stripe latency 2.4s
# 07:23:16 ERR  500 stripe timeout
# 07:23:17 ···  auto-rollback armed
# ...the whole cascade, in order, on every terminal at once.

Two pieces of the documented Pipe API: PUT /api/v1/pipe/[path] on the sender, GET /api/v1/pipe/[path] on every reader, both keyed by the same n. The server forwards the sender's Content-Type, holds the connection up to a 5-minute TTL while it waits for readers, and applies backpressure if any single reader is slow. The replay rate is set entirely by the sender — pv, dd, or any rate-limiter you trust.

use-cases / replay-this-mornings-incident / powers

What watching together does that a doc can't

A scrolling stream changes the conversation. People stop arguing about what happened and start watching what happened. Three properties of the pipe make this work.

MULTIPLAYER BY DEFAULT

Six terminals on the same playhead

n=N is documented in the Pipe API: every reader joining the same path with the same n receives an identical fan-out copy. Eight engineers all see the same line scroll past at the same instant — no one is ahead, no one is squinting at someone else's screenshare.

RATE-LIMITED BY THE SENDER

Replay slow enough to read

Real prod logs scroll faster than humans can absorb. pv -L 50k throttles the replay to a readable pace; the pipe carries whatever rate the sender chooses. You can pause the post-mortem by ctrl-Z'ing the sender and resume by fg — every reader's terminal pauses with you.

EPHEMERAL BY DEFAULT

Replay ends, pipe vanishes

The pipe stores zero bytes. When the cat finishes or the SRE ctrl-C's the sender, the path closes — no leftover endpoint exposed to the internet, no transcript to retention-manage. Run it again from the snapshot for whoever joined the call late.

use-cases / replay-this-mornings-incident / session

How a replay session runs

Four beats from incident-time log to shared post-mortem playback. Nothing here is custom infrastructure — the snapshot lives in hoody-files, the replay rides one Pipe URL.

0107:25
Snapshot the logs
On-call SRE copies /var/log/app at 07:25 into a hoody-files bucket. The file is the source of truth for everything that happened in the cascade window.
0213:55
Open the meeting room
Lead writes a Hoody Pipe URL with ?n=8 (six engineers + two latecomers' headroom) and pastes it into the post-mortem channel. Receivers can connect first — the pipe holds the slot for up to 5 minutes.
0314:00
Press play
The SRE pipes the snapshot through pv -L 50k into the URL. The server waits until eight curls are connected, then the bytes move through once in lockstep — the cascade fires on six terminals at the same instant.
0414:18
Replay for latecomers
The director joins late. Re-run the same line. The pipe is a path, not a place — there's nothing to seek, nothing to rewind, nothing stored on the server. Just press play again.

use-cases / replay-this-mornings-incident / capacity

How big does the room get?

From the documented Pipe API spec. Limits and behaviors that turn a single URL into a post-mortem theater.

READERS PER PATH256
Documented cap on n. Your post-mortem call will not run out of seats — the pipe scales to a whole org.
BYTES STORED0
The pipe is direct-streamed end-to-end. The replay leaves no trace on the server when the sender disconnects.
JOIN WINDOW5 min
Receivers can connect before the sender; the pipe holds the slot up to 5 minutes for late-joiners.

Source: Hoody Pipe API — limits documented for /api/v1/pipe/[path], n parameter (1–256), and unestablished pipe TTL.

use-cases / replay-this-mornings-incident / punchline

The post-mortem isn't a doc. It's a stream everyone watches together.

no scrolling out of sync · no screenshare squintingone URL · eight curls · one playhead

POST-MORTEMyesterdaytoday

ARTIFACTConfluence doc with screenshotshttps://prod-pipe.../pipe/replay
SYNCeveryone scrolls at their own speedlockstep playback for n=8
RETENTIONPDF lives on for yearsctrl-C and the pipe is gone
REPLAYschedule a second Zoomrerun the same curl

Read the pipe API

use-cases / replay-this-mornings-incident / replaces

What this replaces

The set of tools and rituals you currently invoke to walk a team through an incident timeline. Each one stores something, charges per seat, or loses the timing. The pipe is one URL with a shared playhead.

Confluence post-mortem docStatic page with stale screenshots
Notion incident reportBullet list, no synchronized timing
Screenshot pasting in SlackLoses the cascade order and timing
Manual replay-the-logs sessionsOne person scrolls, the rest squint
Recorded Zoom timelineEveryone scrubs at their own pace
Datadog notebook annotationsPer-seat license, no shared playhead

use-cases / replay-this-mornings-incident / cta

The cascade fires on six terminals at once. The conversation changes. People stop arguing about what happened and start watching what happened.

Read the pipe API

use-cases / replay-this-mornings-incident / related

Read the others

Sixty containers on one server

One bare-metal box runs dozens to hundreds of Hoody containers. KSM and BTRFS dedup make the marginal cost near zero.

Containers·Snapshots

Onboard a developer with one link

A new engineer joins on Monday. You send one URL. They open it on whatever laptop they have and they're in a fresh container cloned from your developer-baseline snapshot — code, deps, env, seed data, VSCode-in-browser. Writing code in five minutes, not setting up.

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API endpoints that materialize on demand

A wildcard exec script catches the call, asks an LLM to write the handler, runs it in a V8 sandbox, and saves the route. The next call is native.

Exec·Agent·Code·Files

Branch computers like Git

Snapshot a running container — files, processes, memory. Restore in seconds. Fork via /copy. Branching, but for the entire machine.

Snapshots·Containers

Real VS Code on your phone

The Code Orchestrator spawns a VS Code instance on the container and serves the editor over a normal HTTPS URL. Any device with a browser can open it. The work lives in the container, not on the device.

Display·Terminal·Files·Containers+1

AI agents that spawn other AI agents

A research agent posts to /api/v1/projects/$PID/containers to start a child container, then calls the child's agent URL like any other HTTP service. Sub-agents spawn their own sub-agents the same way. No orchestrator framework, just URLs.

Agent·Exec·Containers

One sandbox per customer, automatically

An exec script catches your signup webhook, copies a fresh-customer container, and hands the new tenant their own URL. Isolation is the operating system, not a tenant_id column.

Containers·Snapshots·Exec·Files

Wake up to a finished prototype

Hand the agent a paragraph at midnight. It spawns its own containers, snapshots before risky steps, and posts to your notification webhook at sunrise.

Agent·Snapshots·Containers·Browser+2

Emergency production fix from your phone

PagerDuty wakes you. Open the terminal URL on your phone. PATCH the snapshot from before the bad deploy. Production is back. No bastion, no VPN, no laptop.

Terminal·Snapshots·Network

Tail production logs to a URL anyone can curl

One pipe URL. Up to 256 readers. Three engineers tail the same incident at once with no bastion, no Datadog seat, no log forwarder.

Push one build to thirty CI workers at once

The build container streams the tarball to a pipe path with ?n=30. All thirty test workers curl the same URL. Bytes go through once, fanned out.

Watch your agent think from the coffee shop

Your agent runs at home. You're at a café. Pipe each event of the loop through Hoody Pipe and curl the same path from your phone — the trace lands character by character. No SSH, no dashboard, no upload.

Move 200GB between clouds with two curls

pg_dump | gzip | curl from Frankfurt. curl | gunzip | psql in Singapore. Bytes flow through the pipe with zero disk in the middle.

Send a teammate a database state in one line

pg_dump streams straight into their psql. No file uploaded, no link shared, no download. The pipe routes the bytes through.

Stream LLM tokens to anything that reads HTTP

Step 3 streams tokens with curl -T -. Step 4 curls the same path. Tokens move generator to consumer at line speed. No SSE plumbing, no broker.

A progress bar your boss can spectate without joining

Append ?progress to the pipe URL. Anyone who opens it gets a live HTML dashboard — bytes, speed, ETA, state. Up to fifty spectators, none consuming a receiver slot, none touching the stream.

The webhook fan-out you didn't have to build

Stripe POSTs to a pipe path with ?n=12. Twelve subscribers curl the receiver URL with ?n=12. The pipe holds the event until everyone is connected.

A CI cache that's just two curl commands

tar | zstd | curl puts node_modules into a pipe. Twenty downstream jobs curl | zstd -d | tar x. No S3 bucket, no cache action, no egress bill.

Pipe·Containers

Drag-drop uploads into your script

hoody-pipe serves a web upload form at every path. Drag a file onto the page, your script reads the bytes from stdin. Zero upload code, no S3 bucket, no presigned URLs.

Broadcast a workshop to 200 viewers from your laptop

ffmpeg streams your screen to a pipe path with ?n=200. Each attendee curls the URL into a browser tab. No platform, no logins, no upload.

Inter-container IPC without the message broker

Container A writes to a pipe path. Container B reads from the same path. Backpressure is the connection. No Redis, no queue, no broker.

Pipe·Containers

Tail your agent on the train, get pinged when it lands

The agent streams its trace to a pipe path you can curl from your phone. When it finishes, its last act hits hoody-notifications and your phone buzzes. Two URLs and a buzz — no SDK, no client app, no dashboard.

Pipe·Agent·Notifications

A microphone over HTTP, in two terminals

ffmpeg captures the mic, pipes to a URL. The other end curls and plays the audio. No Zoom, no SDK, no signaling server.

Five agents, five pipes, one verdict

A panel of five models reviews the same input. Each runs in its own container and streams its verdict to its own pipe path. A judge process curls all five in parallel and tallies the result.

Pipe·Agent·Containers

The fastest 'send me that file' you've ever typed

A teammate pings for a 4 GB dump. Slack rejects it, Drive needs a share request. You type curl -T file …; they type curl … > file. The bytes move directly between disks — no upload bar, no link to share.

Run a local LLM, serve it to your whole fleet

One GPU runs llama.cpp. Its tokens stream into a pipe path with ?n=50. Fifty containers curl the same URL and split the stream.

A live metrics dashboard with no metrics backend

Each container's monitoring loop curls a metric to a pipe URL. The dashboard curls the same URL with ?progress and renders the SSE stream.

The cron job that deletes itself when you're done

POST a managed cron entry with expires_at set 48 hours out. The job runs on schedule, then removes itself — no reminder, no cleanup PR, no stale entry.

Snapshot the container right before the nightly migration

A hoody-cron entry that fires at 02:55 UTC, curls the snapshots URL, and names the artifact pre-migration-2026-05-04. Five minutes later the migration runs. If it succeeds, the snapshot sits idle and costs nothing. If it fails, you restore in 30 seconds with a single PATCH.

Cron·Snapshots

A separate crontab for every customer, automatically

Each tenant gets their own container and their own hoody-cron service. Customer A's 9am digest fires on time even when customer B's job hangs for 40 minutes, because they aren't on the same crontab.

Cron·Containers

Wake an agent at 3am, retire it at 4

A nightly cron POSTs a spawn request, the agent does its hour of work, then a second cron tears the container down. The agent exists only when there is work for it to do.

Cron·Agent·Containers

Daily rollups without an orchestrator

Raw events pile up in a sqlite URL. Every night a cron entry curls an exec endpoint, the script runs the rollup SQL, writes the daily table back. No DAG, no Airflow Postgres, no scheduler dashboard.

Cron·SQLite·Exec

A crontab per branch, deployed with the code

Your repo checks in `.hoody/crontab`. The deploy script PUTs that file to the new container's Cron API. Each branch gets its container, its filesystem, its schedule.

Cron·Containers

On-call escalation that ages out with the shift

POST a cron entry with expires_at = shift end. When the shift ends, the entry deletes itself. The next on-call posts their own.

Cron·Notifications

Hourly scrape, daily digest, weekly archive — one container

Three lines in one crontab: hourly browser scrape into SQLite, daily exec digest, weekly archive to files. Flat-rate server, three rhythms, no scheduler service.

Cron·Browser·SQLite·Files

Let your customers BYO their own cron schedule

Customers POST their own 5-field expressions; their crontab lives in their container, isolated. You don't validate against a global queue.

Cron·Containers

Schedule the agent, not the script

A 5-field cron entry curls hoody-agent with a prompt instead of running a fixed script. Today is the last day of the month — the agent figures it out. The data shape changed — the agent figures it out.

A heartbeat for the silent jobs

Each cron run POSTs a heartbeat to a notifications endpoint. A second cron checks last-heartbeat and pages on silence. Silence is the alert.

Cron·Notifications

Keep the last 24 hours as 24 snapshots

An hourly cron POSTs a snapshot named with the hour. After 24 hours each new snapshot overwrites yesterday's at the same hour. The 24-floor time machine.

Cron·Snapshots

Replay this morning's webhooks at the same time tomorrow

You captured 30 minutes of real Stripe traffic into a hoody-files folder. One cron entry replays it against staging at 9am every weekday — same volume, same payloads, same time-of-day pressure.

Cron·Files·Exec

Edit your crontab from a phone, in the airport

Open the cron URL on your phone in the gate area. Tap a row, change a single field of the cron expression, hit Save. PATCH lands. The job fires tonight on the new schedule. No SSH session, no jump box, no laptop.

A scheduled digest that fans out to 200 inboxes

Cron at 9am POSTs to an exec script that builds the digest and curls a pipe URL with ?n=200. Two hundred recipients hit the same URL once.

Cron·Exec·Pipe

Mute the flaky job without losing it

PATCH /entries/[id] [ enabled: false ]. The job stays in your crontab waiting to be fixed. No deletion, no rewrite, no lost context.

An agent that grades yesterday's agents

A nightly cron POSTs to the supervisor agent with yesterday's agent traces from SQLite. The supervisor scores each one. Cron is the supervisor.

Cron·Agent·SQLite

Cleanup jobs that schedule their own retirement

The cleanup script checks if there's anything left to clean. When the directory is empty, it DELETEs its own cron entry. Job's done, job's gone.

Roll your TLS certificates without an SSH session

Cron weekly: POST to an exec script that runs certbot, posts the new cert to the proxy via PATCH. No shell session, no key, no jump host.

A weekly canary that tries to break production

Sunday 7am cron wakes a Hoody Agent in a fresh container against a snapshot of prod. It runs the OWASP top twenty, fuzzes the API, and writes a findings report to a URL by 9am. Container retires.

Cron·Agent·Browser·Snapshots

The hobby-project graveyard you can afford to keep alive

Eleven half-finished side projects on Heroku is eleven dynos at $5–7 each. On Hoody it's eleven containers on one $29 bare-metal box. Idle costs zero, the URL wakes the container in milliseconds, and the chess engine nobody uses still runs.

A preview environment per pull request, all month

Each open PR gets its own clone of a snapshot. The container wakes when reviewers click the link; idle PRs cost nothing.

Containers·Snapshots

Run a 12-product portfolio from one bare-metal box

Twelve isolated containers, each its own SaaS, share one $49 bare-metal server — a step above the $29 entry tier, chosen here for the RAM headroom fifty containers want. Per-product margins go from negative to nice.

Kill the staging-server tax

Stop paying for a duplicate of production. Snapshot the prod container, branch staging from it on demand, freeze it back to disk when nobody's testing. Three environments, one machine, one bill.

Containers·Snapshots

Forty client sites, one rent, one dashboard

Each client site lives in its own container; you bill them per-site, you pay the host once. The math finally works for agencies.

Containers·Workspaces

Replace the E2B bill with the bare metal you already rent

Your agents stop renting compute by the second from E2B/Modal/Daytona. They use containers on the box you already have.

Containers·Agent·Exec

Idle staging costs nothing, so staging stops getting deleted

Staging used to die because it was expensive to keep around. When idle is free, staging gets to live — even the one a teammate touched 90 days ago.

Containers·Snapshots

Per-customer sandboxes at fleet scale

Eight hundred isolated customers on three bare-metal servers — one flat-rate monthly bill, no per-tenant meter. Each tenant gets a real container with its own kernel namespace, filesystem, and URL. Idle containers cost nothing on top of the server you already pay for.

Containers·Snapshots·Exec

The CI cache that's not an S3 line item

Cache files live in /files on the box you already rent. Workers PUT and GET tarballs over HTTP. No S3 bucket, no egress, no third vendor — the bytes never leave the box.

Files·Containers

Fifty demo environments for fifty sales calls

Each prospect gets a real, isolated copy of your product seeded with their data. Cloned from a snapshot. Theirs to keep for a week.

Containers·Snapshots