S3-compatible object storage with per-request micropayments via Tempo L2
What it does
Object Storage on storage.mpp.tempo.xyz provides S3/R2-compatible object storage accessible through the MPP (Micropayment Protocol). Every HTTP request to the storage endpoint requires a micropayment settled on Tempo L2 (chain ID 4217) using pathUSD. The endpoint at `/:key` supports multipart upload initiation and completion, as well as object retrieval and metadata checks.
The probe captured a HEAD request returning a 402 challenge with intent "charge" and description "Check object", confirming the endpoint is live. The decoded payment request shows an amount of 100 base units of pathUSD (which uses 6 decimals), equating to $0.0001 per HEAD/check-object call. The crawl also reveals that GET requests to the root path trigger a "List objects" payment challenge, and GET requests to sub-paths trigger "Download object" challenges, indicating the service supports standard object storage operations (list, download, upload, check) each gated by individual micropayments.
Pricing appears to be dynamic and per-operation. The currency token address is 0x20c000000000000000000000b9537d11c60e8b50 (pathUSD on Tempo chain 4217). The recipient address is 0xca4e835F803cB0b7C428222B3A3B98518d4779Fe. The service acts as fee payer (feePayer: true), meaning callers do not need native gas tokens. No external documentation or OpenAPI schema was found; all crawled paths returned 402 payment challenges, so the API surface must be inferred from the challenge descriptions and the S3-compatible framing in the existing listing.
Capabilities
Use cases
- —Storing and retrieving files or blobs with per-request micropayments instead of subscriptions
- —Agent-driven file uploads and downloads without pre-provisioned cloud accounts
- —Programmatic multipart uploads of large objects settled per operation on Tempo L2
- —Serving static assets or data objects with pay-as-you-go access control
Fit
Best for
- —AI agents needing on-demand object storage without account setup
- —Developers wanting S3-compatible storage with crypto micropayments
- —Applications requiring fine-grained per-operation billing for storage access
Not for
- —High-throughput bulk storage where per-request micropayments add overhead
- —Users who need traditional IAM/ACL-based access control rather than payment-gated access
- —Workloads requiring guaranteed SLAs with enterprise support contracts
Quick start
# Check if an object exists (HEAD request, costs ~$0.0001 in pathUSD)
curl -I https://storage.mpp.tempo.xyz/my-object-key
# Returns 402 with WWW-Authenticate: Payment header.
# Complete the payment challenge to receive the object metadata.Example
Response
{
"type": "https://paymentauth.org/problems/payment-required",
"title": "Payment Required",
"detail": "Payment is required (Check object).",
"status": 402,
"challengeId": "5Cb9CT4jw_5Bpqr-jnwXRwSK524vKYBJZi8TBNn7o8o"
}Endpoint
Quality
The endpoint is confirmed live via a valid 402 MPP challenge, and basic operation types (list, download, check, upload) can be inferred from challenge descriptions. However, no OpenAPI schema, documentation, or usage examples are available—every crawled path returns only a payment challenge. Pricing details beyond the HEAD check-object call are unknown.
Warnings
- —No documentation or OpenAPI schema found; all paths return 402 payment challenges
- —Pricing for upload, download, and list operations is not captured—only the HEAD/check-object cost ($0.0001) is known
- —Dynamic per-size pricing is mentioned in the existing description but cannot be verified from probe data
- —Currency token address 0x20c000000000000000000000b9537d11c60e8b50 assumed to be pathUSD with 6 decimals based on Tempo L2 conventions; if decimals differ, pricing would change
Citations
- —HEAD request returns 402 with description 'Check object' and amount 100 base units on chain 4217https://storage.mpp.tempo.xyz/:key
- —GET to root returns 402 with detail 'Payment is required (List objects)'https://storage.mpp.tempo.xyz
- —GET to sub-paths returns 402 with detail 'Payment is required (Download object)'https://storage.mpp.tempo.xyz/docs
- —Payment challenge references paymentauth.org problem typehttps://paymentauth.org/problems/payment-required