---
title: "Create or update an assumption under a project (L2 intent layer). Omit `id` to create, pass it to update. There is no delete tool."
method: POST
path: "/api/mcp/tools/assumption_write"
tags: ["misc"]
---

# Create or update an assumption under a project (L2 intent layer). Omit \`id\` to create, pass it to update. There is no delete tool.

`POST /api/mcp/tools/assumption_write`

## Request

- Base URL: `https://api.ainote.dev`
- URL: `https://api.ainote.dev/api/mcp/tools/assumption_write`
- Auth: API key in header `Authorization`

Create or update an assumption under a project (L2 intent layer). Omit `id` to create, pass it to update. There is no delete tool.

🔴 `verdict` is REJECTED with an error if passed — verdict is confirmed only through a human judgment decision (see judgment_submit). This tool can only shape the assumption itself: what is being assumed, how critical it is, and what evidence would settle it.

## Request body

- object
  - `project_id` string, required: Project UUID this assumption belongs to (required).
  - `id` string: Assumption UUID to update. Omit to create a new assumption.
  - `statement` string: What is being assumed true (required to create).
  - `criticality` 1 | 2 | 3: 1=critical if wrong … 3=minor.
  - `evidence_condition` string: What would be observed to settle this assumption. Pass 'null' to clear.
  - `bmc_block` 'key_partners' | 'key_activities' | 'key_resources' | 'value_propositions' | 'customer_relationships' | 'channels' | 'customer_segments' | 'cost_structure' | 'revenue_streams' | 'null': Optional Business Model Canvas block this assumption belongs to. Pass 'null' to clear.

## Response `200`

Tool executed successfully

- ToolSuccessResponse: Successful tool invocation. `content` mirrors the MCP `tools/call` result shape: an array of content blocks (text and optionally a structured resource payload).
  - `content` object[]
    - `type` 'text' | 'resource'
    - `text` string

## Other responses

- `400`: Invalid arguments or business-rule violation
- `401`: Missing or invalid McpKey

---

[API](https://skmtc.dev/ainote/apis/ainote-mcp-openapi-mirror.md) · [All operations](https://skmtc.dev/ainote/apis/ainote-mcp-openapi-mirror/llms.txt) · [OpenAPI document](https://skmtc.dev/ainote/apis/ainote-mcp-openapi-mirror/revisions/f6c91d85e027?raw)