Giving an AI agent access to a social publishing API creates a narrow but consequential security boundary. The agent may prepare text and media, select a public identity, schedule work, and trigger a message that reaches customers. The right question is not whether the model is trustworthy. It is whether the surrounding system limits what any mistaken or compromised client can do.
Start with the assets
A useful threat model names what must be protected:
- provider OAuth tokens for connected social accounts
- product API credentials and agent sessions
- unpublished copy, media, schedules, and audience choices
- the authority to publish, delete, disconnect, or change a schedule
- provider receipts and audit evidence
- webhook secrets and delivery payloads
The public Post matters, but the most sensitive asset is often the reusable authority behind it.
Keep provider credentials behind the service boundary
The agent should not need a Facebook, LinkedIn, X, or TikTok access token. A person can complete provider OAuth in a browser, while the publishing service stores the resulting credential and gives the client a narrower product credential.
That separation reduces accidental token exposure in prompts, transcripts, shell history, application logs, and third-party tool calls. It also gives the service one place to refresh, revoke, and scope provider access.
An API key is not automatically safe because it is different from the provider token. It still needs a clear Workspace scope, revocation path, storage rule, and server-side authorization check on every resource.
Treat public writes as consequential actions
An agent may be allowed to draft freely while publishing requires a separate confirmation. The confirmation should bind the exact content, destinations, media, schedule, and current version. Otherwise an older approval can accidentally authorize a newer edit.
Client prompts and MCP tool annotations can help a user understand an action. They do not replace a server-side authorization rule. The service should decide whether the request is confirmed and authorized before it reaches a provider.
Make retries safe
Networks fail in ambiguous ways. A client can time out after the service accepted a request but before the response arrived. If the agent retries an ordinary create operation, it may create a duplicate public Post.
Idempotency lets the client identify the same logical write. The server can return the original result, reject a reused key with different content, and preserve one stable resource identity. Version checks such as ETags or If-Match protect a different risk: a late agent response overwriting a newer human edit.
You need both controls.
Authenticate asynchronous evidence
Webhooks cross another trust boundary. A receiver should verify a signature over the exact request bytes, reject stale or replayed deliveries when the protocol supports it, and rotate webhook secrets without interrupting every subscriber.
The payload should contain stable identifiers and state transitions, not reusable provider credentials. A successful webhook delivery also does not prove a social provider accepted the Post. Keep the provider receipt and remote object identifier separately.
Log enough to investigate, not enough to leak
Useful audit evidence includes:
- actor or credential identity
- Workspace and resource identifiers
- action and confirmation state
- request and idempotency identifiers
- before and after versions for edits
- per-Destination result and provider receipt reference
- timestamp and structured error code
Avoid logging bearer tokens, provider access tokens, full authorization headers, webhook secrets, or unnecessary unpublished content.
Security questions to ask a vendor
- Can the agent operate without receiving provider OAuth tokens?
- What exactly scopes an API key or agent session?
- Which actions require product-level confirmation?
- How are duplicate retries and concurrent edits handled?
- Are webhook deliveries signed and replay-resistant?
- Can every credential, connection, and webhook secret be revoked independently?
- What evidence remains after a provider accepts or rejects a Post?
- Where is application data stored, and which processors or providers receive it?
The production-readiness checklist expands these questions across the full operating contract. OpenPMM documents its current boundaries on OpenPMM Trust, and its hosted MCP server, API, and CLI use the same product-level credential and confirmation boundary.