# MCP-A2A Task Bridge

> MCP-A2A Task Bridge is a paid API for AI agents from phion.systems, paid per call via x402, $0.004/call, status unknown (last checked 2026-10-22).

Maps MCP and A2A task identities across protocol boundaries while preserving state, authority, and expiry information

## Facts

- Endpoint: POST https://phion.systems/v1/paid/trust/mcp-a2a-task-bridge?utm_source=zero.xyz
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-22
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/mcp-a2a-task-bridge-5ccb680e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_e6twL6UMadrn_jRMd318S

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 mcp-a2a-task-bridge-5ccb680e -d '<json body>'
```

Example prompt: I have an active MCP task with ID task-abc123 that I need to hand off to an A2A agent — bridge the task identity so the state, authority claims, and expiry all carry over correctly without any data loss.

## When to prefer this

Choose this endpoint when an agentic workflow must hand off or share a task between an MCP agent and an A2A agent without losing task state, authority, or expiry. It is the right choice when cross-protocol task identity consistency is a hard requirement — for example, in multi-agent pipelines, protocol migrations, or federated agent systems where both MCP and A2A participants must reference the same logical task.

## Known failure modes

- Invalid or expired MCP/A2A task ID returns a mapping error
- Mismatched authority claims between protocols cause a conflict rejection
- Expired task expiry on input results in a rejected bridge request
- Malformed input schema returns a validation error
- Unknown protocol version or unsupported task format returns an incompatibility error

## How this service works

Map MCP and A2A task identities without losing state, authority or expiry

## Output

Returns a mapped task record containing the translated task identity for both MCP and A2A protocols, the preserved task state, authority claims carried across the protocol boundary, and synchronized expiry metadata — ensuring no loss of context during inter-protocol task handoff.

## 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/mcp-a2a-task-bridge-5ccb680e/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)