---
title: "Average block fees over time"
method: GET
path: "/api/v1/onchain/bitcoin/mining/fees"
tags: ["Digital Economy and Infrastructure"]
---

# Average block fees over time

`GET /api/v1/onchain/bitcoin/mining/fees`

Historical average transaction fees per block. Shows fee trends - higher fees indicate network congestion.

## Query parameters

- `period` string — Time period: 24h, 3d, 1w, 1m, 3m, 6m, 1y, 2y, 3y

## Response `200`

Average block fees time series.

- EnvelopeMempoolMiningFeesData
  - `data` MempoolMiningFeesData, required
    - `period` string, nullable — Time period identifier.
    - `count` union — Number of items in this result set.
      - integer
      - number
    - `fees` Fee[], nullable — Array of block fee records.
      - `avgHeight` union — Average block height for this data point.
        - integer
        - number
      - `timestamp` union — Unix timestamp.
        - integer
        - number
      - `avgFees` union — Average fees per block (satoshi).
        - integer
        - number
      - `USD` union — Value denominated in US Dollars.
        - integer
        - number
  - `meta` SugraMeta, required — Metadata attached to every /api/v1/* response envelope.
    - `endpoint` string, required — Requested endpoint path.
    - `data_time` string, required — ISO 8601 UTC timestamp of the source data, not of the request.
    - `response_time` string, required — ISO 8601 UTC timestamp when this response was produced.
    - `provider` string, required — API name and version.
    - `source` string, nullable — Identifier of the primary upstream source used for this response.
    - `attribution` string, nullable — Human-readable attribution mandated by an upstream source (e.g. a securities regulator or self-regulatory organization). Present only on responses whose source requires the owner and source to be clearly identified. Do not remove or alter it when using the response.
    - `fallback_used` boolean, nullable — True when the primary source failed and a fallback produced the data.
    - `fallback_chain` string[], nullable — Ordered list of sources attempted, in the order they were tried.
    - `cached` boolean, nullable — True when this response was served from the internal cache.
    - `stale` boolean, nullable — True when the cached response was returned after the upstream rate-limited or errored. Clients can use this to detect degraded data.

## Other responses

- `401` — Missing or invalid `x-api-key` header. JSON body with a stable `code` distinguishing `missing_api_key` (no header sent) from `invalid_api_key` (header sent, key not accepted); any other 401 source carries the generic `unauthorized` with its detail as `reason`. Plus `hint`. `plan` is always null on 401 - an unauthenticated request has no plan; quota exhaustion is 429, not 401.
- `422` — Validation Error
- `429` — Daily rate limit exceeded. Check `X-RateLimit-Reset` for the next window.
- `503` — Upstream source is temporarily unavailable. Retry after a short delay.

## Changes

- **2026-08-28** `560e8847c7b3` — 6 breaking
  - the response property `data/count` became optional for the status `200`
  - the response property `data/fees` became optional for the status `200`
  - the response property `data/period` became optional for the status `200`
  - response property `data/count` list-of-types was widened by adding types `null and number` to media type `application/json` of response `200`
  - …2 more
- **2026-08-08** `4c4530760ba1` — 12 info
  - added the optional property `code` to the response with the `401` status
  - added the optional property `code` to the response with the `429` status
  - added the optional property `code` to the response with the `503` status
  - added the optional property `hint` to the response with the `401` status
  - …8 more

[Change history](https://skmtc.dev/sugra/apis/sugra-api/changes/api/v1/onchain/bitcoin/mining/fees/get.md)

---

[API](https://skmtc.dev/sugra/apis/sugra-api.md) · [All operations](https://skmtc.dev/sugra/apis/sugra-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/sugra/sugra-api/revisions/87582f2e0110/schema)