Oauth

Prizmad OAuth 2.1

Prizmad publishes a full OAuth 2.1 authorization server with Dynamic Client Registration. Three grant types are supported, each for a different audience:

| Grant | When | Output | |---|---|---| | authorization_code (PKCE S256, public client) | Interactive MCP / connector flow — Claude Desktop, Claude.ai, ChatGPT, Cursor, Zed | RS256 JWT, audience https://prizmad.com/api/mcp, 1 h, refresh-rotated | | refresh_token | Companion to authorization_code | Same shape; old refresh is single-use, reuse revokes the chain | | client_credentials | Headless / server-to-server using an API key as client_secret | HS256 JWT, audience https://prizmad.com/api, 1 h |

The MCP server also accepts the raw API key (przmad_sk_live_...) as a Bearer token directly, without going through OAuth at all.

Discovery

• Authorization server metadata:
• Protected resource metadata:
• JWKS:

Authorization Code + PKCE (the "Connect" flow)

This is what runs when a user clicks Add custom connector → enter https://prizmad.com/api/mcp in Claude Desktop, Claude.ai, ChatGPT, Cursor, etc. The client implements RFC 7591 / 8414 / 9728 / 7636 / 8707; no manual app registration is needed.

1. POST /api/mcp without auth
   ← 401 + WWW-Authenticate: Bearer resource_metadata="…"

2. GET /.well-known/oauth-protected-resource
   GET /.well-known/oauth-authorization-server

3. POST /oauth/register
   Body (RFC 7591):
     {
       "client_name":  "",
       "redirect_uris": [""],
       "grant_types":   ["authorization_code", "refresh_token"],
       "response_types": ["code"],
       "token_endpoint_auth_method": "none"
     }
   ← 201 { "client_id": "mcp_…", … } (no client_secret — public client)

4. Browser to /oauth/authorize?
       response_type=code
     & client_id=
     & redirect_uri=
     & code_challenge=
     & code_challenge_method=S256
     & scope=videos:read videos:write
     & resource=https://prizmad.com/api/mcp
     & state=
   User signs in (NextAuth) and approves on the consent screen.
   ← 302 redirect_uri?code=…&state=…

5. POST /oauth/token
     grant_type=authorization_code
     code=
     redirect_uri=
     client_id=
     code_verifier=
     resource=https://prizmad.com/api/mcp
   ← 200 { "access_token": "", "refresh_token": "…", "expires_in": 3600, "token_type": "Bearer" }

6. POST /api/mcp with Authorization: Bearer 
   ← MCP traffic.

Refresh:

curl -X POST https://prizmad.com/oauth/token \
  -d grant_type=refresh_token \
  -d refresh_token= \
  -d client_id=

Returns a fresh access token + a new refresh token; the previous refresh is single-use. Reusing a revoked refresh token revokes the entire chain (defence against token theft).

client_credentials (headless / programmatic)

Quickest way to turn a long-lived API key into a short-lived bearer for server-to-server calls.

Form-encoded

curl -X POST https://prizmad.com/oauth/token \
  -d grant_type=client_credentials \
  -d client_id=my-app \
  -d client_secret=przmad_sk_live_...

JSON

curl -X POST https://prizmad.com/oauth/token \
  -H "Content-Type: application/json" \
  -d '{"grant_type":"client_credentials","client_id":"my-app","client_secret":"przmad_sk_live_..."}'

Basic Auth

curl -X POST https://prizmad.com/oauth/token \
  -u "my-app:przmad_sk_live_..." \
  -d grant_type=client_credentials

Response

{
  "access_token": "eyJhbGciOiJIUzI1NiIs...",
  "token_type": "Bearer",
  "expires_in": 3600,
  "scope": "videos:read videos:write"
}

Scopes

| Scope | Description | |-------|-------------| | videos:read | Read video status, projects, assets | | videos:write | Create videos, upload images, mutate projects |

Notes

• All endpoints (/oauth/authorize, /oauth/token, /oauth/register) live on the same origin as the MCP server (https://prizmad.com). This sidesteps the Claude.ai web bug that ignores cross-origin authorization endpoints.
• Access tokens expire after 1 hour. Refresh tokens last 30 days, single-use with rotation.
• API keys (przmad_sk_live_...) continue to work directly as Bearer tokens — OAuth is only needed when the client requires it.
• Rate limit: 10 token requests per minute per identity.
• client_secret field, when used, is your Prizmad API key.
• client_id for client_credentials is a free-form identifier.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: prizmad
• Source: prizmad/agent-skills
• License: MIT
• Homepage: https://prizmad.com

Install and usage instructions live in the source repository linked above.