# Tool Capability Drift Monitor

> Tool Capability Drift Monitor is a paid API for AI agents from phion.systems, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-14).

Detects and reports changes between a trusted baseline snapshot of a tool's capabilities and its current live manifest

## Facts

- Endpoint: POST https://phion.systems/v1/paid/trust/tool-capability-drift-monitor
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/tool-capability-drift-monitor-b4065b4a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_i_i0b_foNAYXfnseFyeaT

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability tool-capability-drift-monitor-b4065b4a -d '<json body>'
```

Example prompt: Before we let the payment tool run again, check whether its current manifest has drifted from the baseline snapshot I approved last week — flag any added or removed capabilities.

## When to prefer this

Choose this endpoint when you need to verify that a specific tool or agent capability hasn't silently changed its declared API surface, permissions, or behavior between trusted checkpoints — especially before re-authorizing a tool in a security-sensitive pipeline, performing compliance audits, or after a tool update. Prefer it over a generic diff tool when you need trust-aware, agent-security-focused comparison with provenance context rather than raw text diffing.

## Known failure modes

- Missing or malformed baseline snapshot causes comparison failure
- Tool manifest URL unreachable or returns non-canonical format
- Schema mismatch between baseline and current manifest versions
- Insufficient fields in input object to identify the tool
- Ambiguous tool identity resulting in wrong baseline being fetched

## How this service works

Detect changes between a trusted tool baseline and its current manifest

## Output

A structured report indicating whether the tool's current manifest matches the trusted baseline, listing any fields that have been added, removed, or modified, along with a trust status verdict and relevant hashes or signatures for auditability.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/tool-capability-drift-monitor-b4065b4a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from phion.systems](https://www.zero.xyz/host/phion.systems/llms.txt)