---
title: "SourceProcedure"
description: "how a source is read, derived from its row and its last reading: how it opens, every table with its count, population and control, the joins, the lineage and the pitfalls"
section: concepts
address: /concepts/sourceprocedure
contract: 0476e35e6e275db5
---

# SourceProcedure

how a source is read, derived from its row and its last reading: how it opens, every table with its count, population and control, the joins, the lineage and the pitfalls

[figure: SourceProcedure is a row at platform scope. The drawing shows its fields and the objects that they point at.]

| property | value |
|---|---|
| kind | row |
| scope | platform |
| key | the source and the reading |
| store | postgres |
| family | sources |



## Fields


| field | type | required | note |
|---|---|---|---|
| `source` | `id` | yes |  |
| `kind` | `one of lake \| catalogue \| folder of files \| hypergraph \| embedding store \| predicate set \| derived table` | yes | one row for every kind |
| `path` | `text` | yes |  |
| `hash` | `hash` | yes | the file at the last reading |
| `generator` | `text` | yes | the program that made it, with its path and commit |
| `engine` | `text` | yes |  |
| `opens` | `text` | yes | the statement that attaches it read-only |
| `tables` | [SourceTable](/concepts/sourcetable) | yes | every table of the artefact with its count, population and control |
| `joins` | [SourceJoin](/concepts/sourcejoin) | yes | to other sources, by identifier |
| `pitfalls` | `[text]` | yes | each with the reading that showed it |
| `read_at` | `time` | yes |  |
| `stale` | `bool` | yes | past the parameter's age |
| `version` | `count` | yes |  |
| `state` | [Readiness](/concepts/readiness) | no | ready when the artefact opened and every table counted; not ready with the reason, such as a missing file or a table with no control; absent on a procedure not yet read |
| `bytes` | `bytes` | no | the size of the file, or of every file of the folder, at the reading; a changed size says the artefact was rebuilt without hashing it again |
| `modified` | `time` | no | when the file, or the newest file of the folder, was last changed, at the reading; a later time says the artefact was rebuilt without hashing it again |



## Routes that use it
- [`/v1/read/source_procedure`](/reference/read/source_procedure) returns it