# Gas Oracle History – Base-Fee Trajectory & Congestion

> Gas Oracle History – Base-Fee Trajectory & Congestion is a paid API for AI agents from x402.professorsausages.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-15).

Returns historical base-fee trajectory and gas congestion data over up to 1024 blocks for a specified blockchain chain.

## Facts

- Endpoint: GET https://x402.professorsausages.com/gas-oracle/:chain/history
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/gas-oracle-history-base-fee-trajectory-congestion-af01d2de
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_HL6BJOJVJJ-XiTA8SNH_G

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 gas-oracle-history-base-fee-trajectory-congestion-af01d2de
```

Example prompt: Can you pull the base-fee trajectory and congestion trend for Ethereum over the last 512 blocks so I can see whether gas is rising or falling right now?

## When to prefer this

Choose this endpoint when you need historical gas context — trend direction, congestion patterns, or fee volatility — rather than just the current gas price. It complements the current-gas-market endpoint by providing the trajectory needed for timing optimization, smart contract scheduling, or alerting logic. Best when you need up to 1024 blocks of granular base-fee and gas-used-ratio series data for EVM-compatible chains.

## Known failure modes

- Unsupported chain identifier returns an error or empty result
- Requested block count exceeds 1024 limit — capped or rejected
- Chain RPC unavailable causes fetch failure
- Very recent blocks may not yet be indexed, causing partial series
- Invalid chain slug returns 400-level error

## How this service works

Base-fee trajectory + congestion over up to 1024 blocks

## Output

Returns a structured object containing the chain name, block range (fromBlock/toBlock), number of blocks analyzed, per-block time series of base fees and gas-used ratios, statistical summaries (min/max/avg) of base fee in Gwei, an overall congestion trend indicator, and the fetch timestamp — giving a full historical gas market picture.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/gas-oracle-history-base-fee-trajectory-congestion-af01d2de/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.professorsausages.com](https://www.zero.xyz/host/x402.professorsausages.com/llms.txt)