---
title: "Idempotent-per-identity mint or attach; portable-identity clients bind to a project"
method: POST
path: "/v1/identity/session"
tags: ["Portable identity"]
---

# Idempotent-per-identity mint or attach; portable-identity clients bind to a project

`POST /v1/identity/session`

## Request

- Base URL: `https://etch.systems`
- URL: `https://etch.systems/v1/identity/session`
- Auth: none declared

The client signs a session challenge with the identity's Ed25519 key; the server either reuses the identity's existing project or mints a fresh one. Bearer returned in the response has mcp:read + mcp:write scopes.

## Request body

- object
  - `external_identity` object, required
  - `use_identity_memory` boolean

## Response `200`

OK

---

[API](https://skmtc.dev/etch/apis/etch-public-api.md) · [All operations](https://skmtc.dev/etch/apis/etch-public-api/llms.txt) · [OpenAPI document](https://skmtc.dev/etch/apis/etch-public-api/revisions/4ff0e74bdb01?raw)