Apostra API

Account-resolved Apostra tools and direct, per-seller AdCP endpoints for agentic advertising.

Build with Apostra npm SDK Skills catalog

Authentication

This server supports OAuth and API key authentication. AI clients (ChatGPT, Claude, etc.) will automatically handle the OAuth flow. You can also authenticate with an API key via the Authorization: Bearer header. Learn more

Skills catalog

Portable, versioned workflows teach compatible agents how to use Apostra safely. Developers can start with Build with Apostra. Buyer workflows cover account readiness, campaign setup and buying, event-source setup, campaign management, Creative Session generation, and local tag-sheet inspection. Seller administrators can follow the OpenAI publication workflow. The catalog also includes direct seller buying and sales-agent validation. Read the machine-readable catalog for current immutable versions.

Authentication Discovery

MCP Endpoints

Apostra V3

The account-resolved Apostra MCP API. One endpoint serves every authenticated Buyer and Seller Account; the active account, permissions, capabilities, and feature availability determine the nouns and tools returned by tools/list. Use V2 REST for deterministic HTTP integrations and operations that V3 does not expose.

Connect your MCP client to:
https://api.interchange.io/mcp/v3
The client will be prompted to authenticate via OAuth.
MCP Tools
  • get_status – Resolve the active account, blockers, and next actions
  • search and get – Read the account's visible nouns
  • save_<noun> – Use only the typed writes advertised for the active account
Build with Apostra

Seller-specific AdCP

Each published Seller can advertise a one-seller AdCP endpoint in its listing. The card selects the Seller protocol door; Apostra remains the agent of record and anchors buyer identity, contract, governance, reporting, and ledger evidence. Follow the card's verified actions[kind=adcp].url; do not substitute the V3 product API.

Canonical endpoint shape:
https://api.interchange.io/seller/{platformId}/mcp
The endpoint selects the Seller. The buyer's credential identifies and authorizes the caller.
Buy from a Seller skill

Stable V2 Endpoints

Buyer API

Stable persona-scoped API for buyer integrations.

https://api.interchange.io/mcp/v2/buyer
API Reference

Storefront API

Stable persona-scoped API for storefront integrations.

https://api.interchange.io/mcp/v2/storefront
API Reference