# OAuth Issuer Binding Evidence

> OAuth Issuer Binding Evidence is a paid API for AI agents from phion.systems, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-20).

Binds verified OAuth issuer and audience claims to an intended receiver, producing signed evidence of the binding

## Facts

- Endpoint: POST https://phion.systems/v1/paid/trust/oauth-issuer-binding-evidence?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/oauth-issuer-binding-evidence-8d9814a7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_wNwkfp50Hm9kXVHX8XQTC

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 oauth-issuer-binding-evidence-8d9814a7 -d '<json body>'
```

Example prompt: Can you verify that this OAuth token's issuer and audience claims are properly bound to our service receiver and generate signed binding evidence I can use as proof?

## When to prefer this

Choose this endpoint when you need cryptographically-grounded, signed evidence that an OAuth issuer and audience are correctly bound to a specific receiver — particularly in agentic pipelines, zero-trust architectures, or compliance scenarios where a simple local JWT check is insufficient and you need an auditable third-party attestation of the binding.

## Known failure modes

- Issuer claim does not match a recognized or verifiable authority — returns validation failure with mismatch detail
- Audience claim does not correspond to the stated intended receiver — returns binding rejection
- Malformed or missing OAuth token claims — returns schema or parse error
- Receiver identity cannot be resolved or verified — returns unresolvable receiver error
- Upstream identity provider unreachable during issuer verification — returns timeout or connectivity error

## How this service works

Bind verified OAuth issuer and audience claims to the intended receiver

## Output

A signed, evidence-bounded record confirming that the provided OAuth issuer and audience claims are verified and properly bound to the specified intended receiver, suitable for audit trails, compliance records, and downstream trust decisions.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input",
  "output"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "additionalProperties": true
    }
   }
  },
  "output": {
   "type": "object",
   "required": [
    "example"
   ],
   "properties": {
    "example": {
     "type": "object",
     "additionalProperties": true
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/oauth-issuer-binding-evidence-8d9814a7/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)