---
title: "Register Harbor Session"
method: POST
path: "/api/harbor/sessions"
tags: ["Harbor Sessions"]
---

# Register Harbor Session

`POST /api/harbor/sessions`

## Request

- Base URL: `https://app.polytomic.com`
- URL: `https://app.polytomic.com/api/harbor/sessions`
- Auth: one of:
  - HTTP bearer
  - HTTP basic

Registers a service-attested MCP transport session for a scoped Harbor credential.

## Headers

- `X-Polytomic-Version` string
- `X-Polytomic-MCP-Key-ID` string: ID of the key that signed the attestation
- `X-Polytomic-MCP-Timestamp` integer: Unix time, in seconds, when the attestation was signed
- `X-Polytomic-MCP-Nonce` string: Single-use value of at least 16 characters included in the signature
- `X-Polytomic-MCP-Signature` string: Attestation signature
- `X-Polytomic-Activity-Request-ID` string: New nonzero UUID for each request, required for scoped credentials; a reused value is rejected.

## Request body

- RegisterHarborSessionRequest
  - `client_name` string: MCP-observed client name
  - `client_version` string: MCP-observed client version
  - `external_run_id` string: Optional client-supplied run correlation value

## Response `200`

OK

- RegisterHarborSessionEnvelope
  - `data` RegisterHarborSessionResponse
    - `expires_at` string, date-time: When the session expires
    - `session_id` string, uuid: Harbor session ID
    - `token` string: Opaque bearer token for subsequent governed requests

## Other responses

- `403`: Forbidden
- `503`: Service Unavailable

## Changes

- **2026-10-22** `d80b0fdea14e`: 1 breaking, 3 warning, 1 info
  - the `data` response's property type changed from `object` to no type for status `200`
  - removed the optional property `data/expires_at` from the response with the `200` status
  - removed the optional property `data/session_id` from the response with the `200` status
  - removed the optional property `data/token` from the response with the `200` status
  - …1 more
- **2026-09-05** `30ade6c6d535`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/polytomic/apis/polytomic-api/changes/api/harbor/sessions/post.md)

---

[API](https://skmtc.dev/polytomic/apis/polytomic-api.md) - [All operations](https://skmtc.dev/polytomic/apis/polytomic-api/llms.txt) - [OpenAPI document](https://skmtc.dev/polytomic/apis/polytomic-api/revisions/3c88180d2470?raw)