# Bitcoin Mempool Pressure State & Projected Next Blocks

> Bitcoin Mempool Pressure State & Projected Next Blocks is a paid API for AI agents from api.chainmarket-api.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-11-02).

Returns the current Bitcoin mempool congestion class (low/normal/high/extreme) and fee projections for upcoming blocks based on backlog and median fee thresholds

## Facts

- Endpoint: GET https://api.chainmarket-api.workers.dev/api/crypto/btc-mempool-pressure?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-11-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/bitcoin-mempool-pressure-state-projected-next-blocks-7bbb3733
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_slX2qHWqyur3miYq5X3ro

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 bitcoin-mempool-pressure-state-projected-next-blocks-7bbb3733
```

Example prompt: What's the current Bitcoin mempool pressure level right now — is it low, normal, high, or extreme — and show me the projected fee rates for the next 5 blocks?

## When to prefer this

Choose this endpoint when you need a deterministic, pre-classified mempool pressure label (low/normal/high/extreme) plus projected next-block fee rates for Bitcoin, especially when you want a single API call that combines congestion state and fee projection rather than raw mempool stats. Ideal for agents making send/no-send decisions, fee optimization workflows, or user-facing dashboards that need actionable status labels rather than raw numbers.

## Known failure modes

- Upstream Bitcoin node unavailability may cause 503 or empty response
- Invalid maxBlocks value outside 1-10 range may return a 400 error
- Network timeouts if the mempool data feed is slow
- Stale data if the underlying node is syncing or lagging

## How this service works

Bitcoin mempool pressure state and projected next blocks. Class (low/normal/high/extreme) is determined deterministically: extreme if next block median fee >= 50 sat/vB or backlog >= 150 vMB; high if >= 20 sat/vB or >= 60 vMB; normal if >= 3 sat/vB or >= 10 vMB; low otherwise.

## Output

Returns the current mempool pressure classification (low, normal, high, or extreme) determined by deterministic thresholds on median fee rate (sat/vB) and backlog size (vMB), along with projected fee data for upcoming Bitcoin blocks (up to the requested maxBlocks count, default 8).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "maxBlocks": {
       "type": "string",
       "description": "Maximum projected blocks to return (1-10, default 8)"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/bitcoin-mempool-pressure-state-projected-next-blocks-7bbb3733/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.chainmarket-api.workers.dev](https://www.zero.xyz/host/api.chainmarket-api.workers.dev/llms.txt)