Your guide to the Pigeon Post Office.
You're the postmaster and the pigeons are your staff. Delivery policies guide how they send your Letters, and results arrive in the Letterbox. Let's make your first delivery.
From an idea to a delivered Letter
- Set a delivery policy
Create a delivery policy. Start with HTTP/2 and choose the timeouts and retries your endpoint needs.
Client settings โ - Build a Letterflow
Add a Letter component, select its region and Delivery Policy, and configure its request.
Write your request โ - Send it once
Run the saved Letterflow from the dashboard. Resolve any readiness warnings before sending.
Open your post office โ - Open the Letterbox
Inspect the response and the HTTP version actually used. Once it works, add a Schedule or build a Letterflow.
Read the result โ
One concept at a time
Follow the guide in order, or go straight to the part you need.
Directory
Share encrypted regional values, headers and credentials across Letterflows.
Delivery Policy
The reusable settings behind every delivery: HTTP versions, timeouts, retries, and payload limits.
Delivery policy โLetterflows
Connect Letters, Conditions, and Values. Pass data forward and share cookies within a run.
Connected steps โSchedules
Send once, repeat a delivery, or use cron. Understand intervals, quotas, and paused schedules.
Delivery timetable โDelivery queues
Let work wait for capacity. Manage admission order, frozen inputs, and scheduled occurrences.
Review, reorder, or remove โLetterbox
Read responses and historical Letterflow paths. Search, pin, and manage retained results.
Delivery history โIntegration API
Use scoped keys to inspect history, run saved requests, and poll execution from your own tools.
Your tools, connected โKnow your allowances
Plan allowances are shared across your account and all regions. Account-specific exceptions may apply.
| Per account | Tinkerer | Aspiring | Coder |
|---|---|---|---|
| delivery policies | 1 | 5 | 20 |
| Letterflows | 3 | 15 | 50 |
| Directory | 5 | 30 | 100 |
| Saved schedules | 20 | 20 | 20 |
| Reachable attempts / hour | 12 | 180 | 720 |
| Concurrent runs | 1 | 3 | 10 |
| Minimum interval (minutes) | 10 | 1 | 1 |
| Retained Letterbox entries | 10 | 80 | 250 |
| Retention (days) | 14 | 60 | 180 |
| Active API keys | 1 | 3 | 5 |
| Components / Letter components | 6 / 2 | 15 / 5 | 25 / 10 |
| Request body / response body (MiB) | 3 / 3 | 15 / 20 | 30 / 50 |
Start does not count toward component limits. MiB uses 1,048,576 bytes. Pinned entries still use Letterbox capacity.
Each reachable Letter attempt, redirect hop, and retry counts toward the rolling hourly allowance. Values and Conditions do not. Deleting history does not restore request quota.
- Names: 60 characters
- Letterflow descriptions: 1000 characters
- Step IDs: 100 characters
Send the post office a note.
A question, a confusing delivery, or an idea for Hato? Send a message and we'll reply by email.