# Agent Handoff Diff

> Agent Handoff Diff is a paid API for AI agents from agent-product-normalizer.vercel.app, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-18).

Computes and returns the delta between two agent handoff states so the receiving agent only processes what changed

## Facts

- Endpoint: GET https://agent-product-normalizer.vercel.app/api/v1/handoff-diff
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-18
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent-handoff-diff-b7285275
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_kj1AimMdbExitRR5K_YpG

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 agent-handoff-diff-b7285275
```

Example prompt: Show me only what changed between these two agent handoff states — the earlier one is [before state text] and the newer one is [after state text] — so I can pass just the delta to the next agent.

## When to prefer this

Choose this endpoint when orchestrating multi-agent pipelines where passing the full context on every handoff is token-inefficient or costly. It is especially valuable when agent states are large and only a small portion changes between steps, or when you need to audit what an agent actually modified during its execution turn.

## Known failure modes

- Missing 'before' or 'after' query parameters returns a validation error
- State strings exceeding 20,000 characters are rejected
- Identical before and after states return an empty delta
- Malformed or non-serializable state strings may cause parsing errors
- Network timeout if states are very large near the character limit

## How this service works

Report what changed between two agent handoff states so the next agent reads only the delta

## Output

A structured delta report highlighting what fields or content changed between the 'before' and 'after' agent states, including additions, deletions, and modifications — enabling the receiving agent to ingest only the changed information rather than the full state.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "before",
      "after"
     ],
     "properties": {
      "after": {
       "type": "string",
       "maxLength": 20000,
       "description": "Newer agent state"
      },
      "before": {
       "type": "string",
       "maxLength": 20000,
       "description": "Earlier agent state"
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent-handoff-diff-b7285275/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent-product-normalizer.vercel.app](https://www.zero.xyz/host/agent-product-normalizer.vercel.app/llms.txt)