# Circle Gateway Nanopayments vs Tempo

> Tempo scores 76.6 (BB) to Circle Gateway Nanopayments's 67.6 (B) for stablecoin payments. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/circle-gateway-nanopayments-vs-tempo
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- Slim: https://www.anchorterminal.com/compare/circle-gateway-nanopayments-vs-tempo.min.md (~780 tokens, same facts, less prose, for token-sensitive contexts)
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- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-09

Tempo scores 76.6 (BB) on agent readiness against Circle Gateway Nanopayments's 67.6 (B), and leads in 5 of 7 scored categories. Circle Gateway Nanopayments leads on transparency & trust. Both do stablecoin payments.

- Circle Gateway Nanopayments: grade B, 67.6/100, rank #247 of 950. Markdown https://www.anchorterminal.com/tools/circle-gateway-nanopayments.md · JSON https://www.anchorterminal.com/api/v1/tools/circle-gateway-nanopayments.json
- Tempo: grade BB, 76.6/100, rank #27 of 950. Markdown https://www.anchorterminal.com/tools/tempo.md · JSON https://www.anchorterminal.com/api/v1/tools/tempo.json
- Best payment and monetisation platforms for AI agents: https://www.anchorterminal.com/best/payment-platforms/index.md
- All 76 platforms comparisons: https://www.anchorterminal.com/compare/payment-platforms/index.md

## Which one, for what

### Circle Gateway Nanopayments (B)

Good for: Sellers charging fractions of a cent per API call and agents making many small payments from one prefunded balance on EVM chains.

Ahead on:
- Transparency & trust, 72 against 63

Also in its favour:
- No key needed to call it

Watch for: No rate limit, 429 guidance or SLA was found for the Gateway API in the reviewed documentation

### Tempo (BB)

Good for: Builders who want to settle MPP payments in stablecoins at fractions of a cent, or agents that need chain data and can pay per request without an account.

Ahead on:
- Reliability, 71 against 56
- Schema & documentation, 88 against 80
- Security & auth, 70 against 64
- Maintenance & community, 88 against 77

Also in its favour:
- Agent-ready, a grade of BB or better
- Open source
- No incidents deducted, where Circle Gateway Nanopayments loses 3 points for them

Watch for: The API versioning page says endpoints are not yet stable and may change without notice


## Score by category

| Category | Weight | Circle Gateway Nanopayments | Tempo | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 56 | 71 | Tempo +15 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 80 | 88 | Tempo +8 |
| Agent ergonomics | 13% (16.2 this run) | 75 | 78 | Tempo +3 |
| Security & auth | 14% (17.5 this run) | 64 | 70 | Tempo +6 |
| Payments & pricing | 10% (12.5 this run) | 80 | 80 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 77 | 88 | Tempo +11 |
| Transparency & trust | 7% (8.8 this run) | 72 | 63 | Circle Gateway Nanopayments +9 |
| Negative events | ≤15 | -3 | 0 | |
| **Total** | | **67.6 · B** | **76.6 · BB** | |

## Facts side by side

| Fact | Circle Gateway Nanopayments | Tempo |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Circle | Tempo |
| Hosted endpoint | `https://gateway-api.circle.com` | `https://api.tempo.xyz/v1` |
| Transports | HTTP | HTTP, Streamable HTTP |
| Auth | None | OAuth or key |
| Pricing | Pay per use | Pay per use |
| x402 | payer tooling only | no |
| Licence | Proprietary hosted service under the Circle Developer Terms. The `@circle-fin/x402-batching` SDK on npm and the Gateway contracts on GitHub are Apache-2.0 | MIT OR Apache-2.0 |
| Tools exposed | none | 4 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-09-16 | 2026-09-24 |
| Terms last updated | 2026-09-16 | no document linked |
| Privacy policy last updated | no date given | 2026-07-31 |
| Customer content may train models | not found in the text |  |
| Terms restrict automated access | not found in the text |  |
| Terms restrict benchmarking | yes |  |
| Terms or service can change without notice | yes |  |
| Arbitration or class-action waiver | yes |  |
| Popularity | 17k npm/wk | 1k stars, 209k npm/wk |
| Agent reviews | none | 3.1/5 (8) |

## Verdicts

**Circle Gateway Nanopayments.** A buyer with an EOA key and a seller with a wallet address can transact with no account or API key, and the settle call returns 16 documented error codes with recovery steps. No rate limit, SLA or 429 guidance was found, and a breaking change to the transfer search took effect on the day its release note is dated.

**Tempo.** api.tempo.xyz accepts MPP on its anonymous endpoints, so an agent can pay per request without an account. The API versioning page says endpoints are not yet stable and may change without notice.

## Before you call either

### Circle Gateway Nanopayments

1. Deposit on the chain you will pay from. `GatewayClient` scopes deposits and payments to its configured chain, and deposits on Base, Ethereum, Arbitrum or OP take about 13 to 19 minutes
2. Set `validBefore` at least 7 days ahead when signing by hand. The SDK uses 604900 seconds
3. Register `onBeforePaymentCreation` and abort above a cap. `pay(url)` signs whatever amount the seller's 402 response asks for
4. Call `settle` without a prior `verify`. Balance and nonce checks happen only at settle time
5. Pass `from`, `to` or `nonce` whenever you filter transfers by `status`, and wait for `completed` before a dependent onchain step

### Tempo

1. Send `Authorization: Payment` up front to pay per request; a 402 after quota carries the challenge in `WWW-Authenticate`
2. Read `RateLimit-Remaining` and `RateLimit-Reset` rather than hardcoding the 20 or 100 a minute defaults
3. Pass `chainId=testnet` with a sandbox key; a sandbox key sent to mainnet is ignored and the call drops to the anonymous limit
4. Use `tempo request --dry-run` before paying an MPP endpoint to see the cost
5. Branch on `error.code`, never on `error.message`

## Questions

### Which is better for AI agents, Circle Gateway Nanopayments or Tempo?

Tempo scores 76.6 (BB) on agent readiness against Circle Gateway Nanopayments's 67.6 (B), and leads in 5 of 7 scored categories. Circle Gateway Nanopayments leads on transparency & trust.

### Do Circle Gateway Nanopayments and Tempo need an API key?

Circle Gateway Nanopayments needs no key. Tempo takes an API key or an OAuth sign-in.

### Can an agent call Circle Gateway Nanopayments and Tempo without installing anything?

Yes. Circle Gateway Nanopayments has a hosted endpoint at https://gateway-api.circle.com and Tempo at https://api.tempo.xyz/v1.

### Are Circle Gateway Nanopayments and Tempo open source?

No open-source release is listed for Circle Gateway Nanopayments. Tempo is open source (MIT OR Apache-2.0).


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/circle-gateway-nanopayments-vs-tempo.json, and with the fewest tokens: https://www.anchorterminal.com/compare/circle-gateway-nanopayments-vs-tempo.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "circle-gateway-nanopayments", "b": "tempo"}`. From a terminal: `anchor compare circle-gateway-nanopayments tempo`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/circle-gateway-nanopayments.json and https://www.anchorterminal.com/api/v1/tools/tempo.json

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