---
title: "Similarity between two texts"
method: POST
path: "/v1/similarity"
tags: ["Kairos passthrough"]
---

# Similarity between two texts

`POST /v1/similarity`

## Request

- Base URL: `https://api.infolang.ai`
- URL: `https://api.infolang.ai/v1/similarity`
- Auth: one of:
  - HTTP bearer
  - HTTP bearer

Proxied verbatim to Kairos. The gateway applies NO authentication of its own here — /v1 and /mcp sit outside the /v2 middleware, so the Authorization header is forwarded untouched and Kairos is the sole authority. In practice that means either `il_*` credential is accepted (an API key, or an `il_oauth_` token — the latter is how an MCP client reaches /mcp); a Supabase session JWT is NOT, since Kairos cannot verify one. Response shapes are owned by Kairos. The gateway forwards ALL methods under /v1/* and /mcp — the operations listed here are the primary surface, not an exhaustive proxy inventory.

## Request body

- object
  - `text1` string, required
  - `text2` string, required

## Response `200`

Similarity score

---

[API](https://skmtc.dev/infolang/apis/infolang-api.md) · [All operations](https://skmtc.dev/infolang/apis/infolang-api/llms.txt) · [OpenAPI document](https://skmtc.dev/infolang/apis/infolang-api/revisions/d04bf6de72c8?raw)