# Foundry by InversoLabs
> Machine-payable capabilities that autonomous agents can buy instead of rebuilding.

## Temporary Authenticated A2A Callback Inbox
- Capability: Provision a private, authenticated, task-scoped HTTPS callback inbox for asynchronous agent workflows.
- Compute advantage: Suspend the reasoning agent while work is pending. A lightweight worker receives and stores the callback so model compute resumes only when a result exists.
- Purchase unit: One temporary mailbox; callback messages are included and are not billed individually.
- Price: 0.005 USDC
- Settlement: x402 v2 using USDC on Base or Solana
- Paid endpoint: https://callbacks.inversolabs.us/v1/services/agent-callback-mailbox/invoke
- OpenAPI: https://callbacks.inversolabs.us/openapi.json
- Agent service metadata: https://callbacks.inversolabs.us/.well-known/agent-service.json
- x402 metadata: https://callbacks.inversolabs.us/.well-known/x402
- MCP endpoint: https://callbacks.inversolabs.us/mcp
- Human-readable pricing: https://callbacks.inversolabs.us/pricing
- Installable Agent Skill: https://callbacks.inversolabs.us/skills/agent-callback-mailbox.zip
- Skill instructions: https://callbacks.inversolabs.us/skills/agent-callback-mailbox/SKILL.md
- Independent Agent402 listing: https://agent402.tools/api/index?seller=callbacks.inversolabs.us
- Version: 0.1.54

Agents should send a stable Idempotency-Key, inspect the HTTP 402 payment challenge, settle the advertised terms, and retry the identical request with PAYMENT-SIGNATURE. The caller generates separate ingress and retrieval credentials; never send wallet seed phrases or private keys.

A successful paid invocation returns JSON containing mailbox_id, callback_url, authentication_scheme, expires_at, max_events, and max_bytes. Illustrative schema-valid response (not a recorded customer transaction):
```json
{"mailbox_id":"example-mailbox-id","callback_url":"https://callbacks.inversolabs.us/callbacks/example-mailbox-id","authentication_scheme":"Bearer","expires_at":"2026-08-20T14:00:00+00:00","max_events":100,"max_bytes":1048576}
```
The callback_url is immediately usable with the caller-generated ingress credential; retrieve ordered events using the separate retrieval credential.

## Illustrative compute-savings example
A 30-minute task checked every 15 seconds creates 120 polls. If an orchestration design invokes a model on every check, that is 120 unnecessary reasoning cycles before the result arrives. With this mailbox, the agent supplies one callback URL, suspends, and resumes after a lightweight worker observes the stored event. Exact token and dollar savings depend on the buyer's model and orchestrator; ordinary HTTP checks do not themselves consume model tokens unless the buyer routes them through a model.