---
title: "The kernel"
description: "The kernel: the 7 calls this system serves, each a route of the API and a tool of the MCP server, at contract 0476e35e6e275db5."
section: systems
address: /systems/01-the-kernel
contract: 0476e35e6e275db5
---

# The kernel

The kernel: the 7 calls this system serves, each a route of the API and a tool of the MCP server, at contract 0476e35e6e275db5.

[figure: The kernel: 7 calls of the contract, by family.]

# The kernel

The 7 calls below are the whole of this system on the wire: each is one route of the API and one tool of the MCP server, with one typed input, one card as its answer and one refusal shape. Every answer carries its foot: what was read, the population and the control.

## The calls



| tool | route | takes | gives |
|---|---|---|---|
| [si.read.parameter](/reference/tools/si-read-parameter) | [POST /v1/read/parameter](/reference/read/parameter) | its name | its value, with its dimension and version |
| [si.read.under_test](/reference/tools/si-read-under_test) | [POST /v1/read/under_test](/reference/read/under_test) | a subject or a scope, and the two dates | every hypothesis about it with its standing, its evidence for and against, the tests run and the tests owed, and what would settle each |
| [si.read.unit](/reference/tools/si-read-unit) | [POST /v1/read/unit](/reference/read/unit) | the kind, the id, the caller | the unit |
| [si.act.correct](/reference/tools/si-act-correct) | [POST /v1/act/correct](/reference/act/correct) | the id of the wrong event, and the right facts | a correcting event |
| [si.act.parameter](/reference/tools/si-act-parameter) | [POST /v1/act/parameter](/reference/act/parameter) | a parameter by its name, its value and its scope | the parameter as written, at its new version |
| [si.act.settle](/reference/tools/si-act-settle) | [POST /v1/act/settle](/reference/act/settle) | a hypothesis, the standing, the caller | the hypothesis settled, with who settled it and on what |
| [si.act.weigh](/reference/tools/si-act-weigh) | [POST /v1/act/weigh](/reference/act/weigh) | a hypothesis, and a fact or a test's reading | the hypothesis with the evidence attached and its standing recomputed against its bar |



## The bars this system enforces

Every bar is a row of the parameter register: an administrator changes it, and the platform reads it by name at the place of enforcement the row records.

| parameter | family | dimension | enforced at |
|---|---|---|---|
| the longest wait of each place of a kind | machinery | a time for each place | the place's reader, and the ops console that counts units past it |
| the time within which a move of a unit ends | machinery | a time | the kernel's move, measured at the first build stage and then fixed |