Compare/Veto vs Alter

Veto vs Alter

Alter and Veto both appear in the "AI agent security" category, but they solve fundamentally different problems. Alter is the auth layer for AI agents. It manages who the agent is and what credentials it holds. Veto is the authorization boundary. It controls what the agent does with those credentials. Understanding this distinction is the whole comparison.

The core distinction

Alter answers: "Does this agent have valid credentials to access this API?" It manages OAuth tokens, issues ephemeral scope-narrowed credentials, and handles token rotation. Think of it as a credential vault with policy.

Veto answers: "Should this agent be allowed to make this specific tool call with these specific arguments?" It intercepts tool calls, evaluates them against policies, and routes review-required actions to human approval. Think of it as a firewall between the agent's intent and execution.

An agent with valid OAuth credentials (Alter's domain) can still approve a $500K transaction it should not (Veto's domain). These are different security controls.

Feature comparison

CapabilityVetoAlter
Tool-call authorization
Declarative YAML policies
Human review approvalsPartial
OAuth credential vaulting
Ephemeral token issuance
Token scope narrowing
RBAC and ABAC policies
Decision records
Open source SDK
Self-hosted option
MCP gatewayPartial
Framework integrations (LangChain, etc.)
Embeddable OAuth widget
broad provider connector catalog
Local offline mode

Where each excels

Alter's strength: credential lifecycle

Alter's credential-leasing product depth is outside Veto's scope. When your agent needs to call the Salesforce API, Alter issues a seconds-lived, scope-narrowed OAuth token for exactly that request. The token expires immediately after use. No long-lived API keys sitting in env files, no over-scoped service accounts, no token rotation scripts.

Credential sprawl is a material security problem in agent systems. If credential scope and token rotation are the failure mode, Alter is built for that job.

Alter also provides an embeddable OAuth widget and broad provider connector catalog, which significantly reduces the integration work for teams connecting agents to external services.

Veto's strength: tool-call control

Veto operates at a different layer. Even with perfectly scoped credentials, an agent can still make wrong decisions. A claims processing agent with valid database credentials can approve a $500,000 settlement when the authority limit is $50,000. A customer service agent with valid CRM access can read medical records to answer a billing question.

Veto intercepts the tool call itself, the function name, the arguments, the context -- and evaluates it against declarative policies before execution. It does not manage credentials; it governs what happens after authentication succeeds.

The SDK is open source (Apache-2.0), policies are YAML files in your repo, and the policy engine runs locally in your process. Core authorization logic stays portable.

The security control model

Think of agent security as a stack. Each layer addresses a different threat:

Layer 3: Runtime authorization

Should this agent make this specific tool call with these arguments?

Veto

Layer 2: Credential management

Does this agent have valid, minimally-scoped credentials for this API?

Alter

Layer 1: Authentication

Is this agent who it claims to be?

Both plus Auth0

These layers are complementary. You can use Alter to manage credentials and Veto to authorize actions. Or you can use either independently. The question is which layer addresses your primary security concern.

Pricing

Veto

Open Source runs locally. Core adds shared approvals, decision records, export, and retention. See the pricing page for price, retention, and action limits. Self-host the SDK and API server for $0 if you prefer. No per-agent or per-seat pricing.

Alter

Public pricing can change. Use the current Alter quote for procurement, then compare the full rollout cost against Veto's governed-action meter.

Decision framework

Choose Veto when

  • Your primary risk is agents taking wrong actions, not credential leakage
  • You need human approval workflows for review-required operations
  • You want an open source solution you can inspect, fork, or self-host
  • You need declarative policies that live in version control
  • You already handle your own authentication and OAuth

Choose Alter when

  • Your primary risk is credential sprawl and over-scoped API keys
  • You need ephemeral, scope-narrowed OAuth tokens per request
  • You are connecting agents to many third-party services (broad connector catalog)
  • You want managed credential lifecycle (rotation, expiry, revocation)
  • You need an embeddable OAuth widget for end-user connections

Frequently asked questions

Can I use Veto and Alter together?
Yes, and it is a reasonable architecture. Use Alter to manage which credentials your agents hold (Layer 2), and Veto to authorize which actions they take with those credentials (Layer 3). Alter can keep the agent on a minimally-scoped Salesforce token; Veto gates the agent does not use that token to delete all contacts.
Does Alter's fine-grained RBAC do the same thing as Veto's policies?
There is some overlap in concept, but the enforcement point is different. Alter's policies operate at the API access layer, controlling which endpoints and parameters an agent can reach. Veto's policies operate at the tool-call layer, evaluating the agent's actual function calls, their arguments, and routing to human approval. If you need "block DROP TABLE in production," Alter can do that. If you need "route claims over $50K to a supervisor for approval before the tool call executes," that is Veto.
Which integration is less invasive?
Both are designed for SDK-level integration. Veto wraps existing tool definitions; Alter changes credential management. If you already handle identity and credentials, Veto is usually the smaller runtime change because it sits at the execution boundary. Alter requires more upfront work (migrating credentials, setting up OAuth connections) but gives you managed credential lifecycle afterward.
Is Alter open source?
Alter is a managed credential platform. This is a reasonable choice for a credential vault, you should not to self-host your OAuth token infrastructure. But it means vendor dependency: if Alter changes pricing, has an outage, or sunsets a feature, you have limited recourse. Veto's SDK is Apache-2.0 open source, so self-hosting and forking remain available control paths.

Authorize the action, not only the identity.

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