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lesson // bitcoin

Block Explorer UI

Visualize blocks, transactions, and mempool activity in a web dashboard.

intermediate2 weeksproject // block-explorer

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Learning objectives

  • Index or query blocks, txs, and addresses for display
  • Present mempool fee histograms or recent transactions
  • Handle loading, empty, and error states cleanly

study // plan

Lessons are primers. Start with Step 1 (required reading) when present, then follow the numbered steps in the article. Depth comes from primary sources, labs, reflection, and evidence.

Research on Bitcoin Search
block explorerEsplora APImempool visualization

Step 1 // Required reading

Complete these before the numbered steps in the lesson body. Links are listed here once — not repeated below.

  • docsProject Spec: Block Explorer

    Pull project page — acceptance criteria and submit flow.

  • bookMastering Bitcoin

    Ch. 11: Bitcoin Blockchain

Reflection prompts

  1. Explain Block Explorer UI to a teammate without jargon - what problem does it solve?
  2. What would break in production if you misunderstood Block Explorer UI?
  3. Which BIP, book chapter, or Core doc is authoritative here, and what did you verify?

Lab // Project milestone evidence

Complete Steps 2–4. Ship the explorer happy path on regtest (or an Esplora-compatible API) and capture demo evidence before marking complete.

evidence required

  • ·Link to public repo or branch
  • ·Screenshots or recordings of block, tx, and address views
  • ·Short note of one failure case (missing tx, empty mempool, RPC down)
  1. 01

    Worked mental model

    Re-read the diagrams in this lesson once out loud in plain language. If you cannot explain the flow to a friend without jargon, pause and revisit the Mastering Bitcoin / Mastering Lightning chapters linked in Resources. Chapter references are intentional, not decorative.

  2. 02

    Hands-on habit

    Every protocol idea should be paired with one local experiment. That habit turns reading into builder instinct.

    1. Reproduce the happy path on regtest (or Polar for Lightning)
    2. Break it on purpose (wrong fee, expired invoice, offline peer)
    3. Write down what error you saw and which layer produced it (wallet, node, mempool, peer)
  3. 03

    Glossary check

    Pick three terms from this lesson and define them in one sentence each without opening notes. Weak definitions mean the lesson is not finished yet.

  4. 04

    Resource order

    Use Resources in order: narrative book chapter first, then BIP/BOLT for precision, then implementation docs for commands. Jumping straight to RPC flags without the mental model creates brittle knowledge.

Explorers teach users (and you) how the chain looks. Build a focused UI over regtest or an Esplora-compatible API.

Complete Step 1 // Required reading in the study plan above, then continue here.

Step 2 — Goal

Create pages for:

  • Recent blocks
  • Transaction detail (vin/vout, fee, weight)
  • Address summary (funded txouts)

Optional: pending mempool list or simple fee histogram.

Loading diagram…

UI reads indexed chain data; keep heavy indexing off the request path when possible.

Done when: You can sketch the three primary routes and their data sources.

Step 3 — Milestones

PhaseShip
Milestone ABlock list + block detail from Core/Esplora
Milestone BTransaction and address views with loading/empty/error states
Milestone CMempool pending list or fee snapshot

Don't scrape RPC on every click

Cache recent blocks. RPC fan-out per page view will feel slow and fragile.

Done when: Milestone A is usable before you polish charts.

Step 4 — Build & evidence (lab)

Implement against /projects/block-explorer. Capture repo link, UI proof, and one failure case.

Common mistakes

  • Blocking the UI thread on full-chain scans
  • Showing raw RPC errors to end users
  • Assuming mempool views are identical across peers

Done when: Lab evidence is filed.

Next lesson

Node Dashboard — peers, sync, and fee estimates as live ops signals.

further reading

  • docsEsplora API
  • toolMempool.space

review // club

Review club

Practice on real Bitcoin OSS changes tied to this chapter. Read the diff, use the checklist, and optionally paste your review comment URL in your lab notes.

  • Mempool.space explorer GFI

    Compare mempool.space's fee views with what you'd build in the block explorer project.

    gfi
    UXfee visualization
    30 min·beginneropen on GitHub
review checklist
  1. Does the change solve the stated problem?
  2. Are edge cases and rollout behavior covered?
  3. Are tests or test vectors included?
  4. Is the diff minimal and clearly explained?

More repos and GFIs on /discover and /issues.

build // challenge

project // block-explorer

./open-spec./submit

Apply what you learned in a focused build session. Ship something small, test it on regtest, and document your approach before moving on.

progress // sign in

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discussion

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