# Camp: free, tip-fresh, decoded Graph Horizon data on Arbitrum One **URL:** \ **Category:** Community & Grants\ **Created:** [May 29, 2026, 12:40pm UTC](https://forum.thegraph.com/t/camp-free-tip-fresh-decoded-graph-horizon-data-on-arbitrum-one/6980 "2026-05-29T12:40:11Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![AxiomaticAardvark](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.thegraph.com/axiomaticaardvark/32/2935_2.png) [@AxiomaticAardvark](https://forum.thegraph.com/u/AxiomaticAardvark)\ **Post date:** [May 29, 2026, 12:40pm UTC](https://forum.thegraph.com/t/camp-free-tip-fresh-decoded-graph-horizon-data-on-arbitrum-one/6980/1 "2026-05-29T12:40:11Z")
A community Amp node serving decoded protocol events over a small REST API — no signup, no API key. This post is a deep dive aimed squarely at the people in this forum: indexers, delegators, regular graph nerds, etc **Live:** [https://engine.camp/](https://engine.camp/) · **Source (MIT):** [GitHub - lodestar-team/camp: Free Dune-class data API for Arbitrum One 🏕️ · GitHub](https://github.com/lodestar-team/camp) * * * ## TL;DR - camp is a free REST API over an **Amp** node indexing **Arbitrum One** at chain tip. - It serves **12 decoded Graph Horizon staking events** — provisions, delegations, stake, and slashing — with full `uint256` precision, addresses already un-padded, no ABI required on your end. - Everything is one bounded SQL query under the hood. There’s also a **raw `POST /v1/sql`** escape hatch if the canned endpoints don’t cut it. - It’s a community service: free, no SLA, rate-limited per IP. If you need guaranteed latency, the whole stack is open — run your own in an afternoon. * * * ## The problem this solves Horizon staking data lives in event logs on the `HorizonStaking` contract on Arbitrum One (`0x00669a4cf01450b64e8a2a20e9b1fcb71e61ef03`). Getting at it usually means one of: 1. **Run an archive node + write decode logic.** Works, but it’s your infra, your ABI plumbing, your `uint256`-in-JavaScript precision bugs. 2. **Write a subgraph.** Great for production dapps, heavy for “I just want to see every slashing event this week.” 3. **Use a hosted analytics product.** Often gated, often lagging the tip by minutes-to-hours, often not free. camp is the fourth option: a public endpoint where `GET /v1/horizon/provision-slashed?from_block=…&to_block=…` returns clean, typed JSON, updated at chain tip, for free. It’s deliberately narrow — raw indexed event history and lookups, not a balances/pricing/analytics platform — and that narrowness is what keeps it fast and cheap to run. * * * ## What’s actually decoded (the Horizon surface) camp exposes a catalog at `GET /v1/horizon`, then one endpoint per event at `GET /v1/horizon/{slug}`. The twelve events currently covered: | Slug | Event | Notable fields | | --- | --- | --- | | `horizon-stake-deposited` | `HorizonStakeDeposited` | `serviceProvider`, `tokens` | | `horizon-stake-locked` | `HorizonStakeLocked` | `serviceProvider`, `tokens`, `until` | | `horizon-stake-withdrawn` | `HorizonStakeWithdrawn` | `serviceProvider`, `tokens` | | `provision-created` | `ProvisionCreated` | `serviceProvider`, `verifier`, `tokens`, `maxVerifierCut`, `thawingPeriod` | | `provision-increased` | `ProvisionIncreased` | `serviceProvider`, `verifier`, `tokens` | | `provision-thawed` | `ProvisionThawed` | `serviceProvider`, `verifier`, `tokens` | | `tokens-deprovisioned` | `TokensDeprovisioned` | `serviceProvider`, `verifier`, `tokens` | | `provision-slashed` | `ProvisionSlashed` | `serviceProvider`, `verifier`, `tokens` | | `tokens-delegated` | `TokensDelegated` | `serviceProvider`, `verifier`, `delegator`, `tokens`, `shares` | | `tokens-undelegated` | `TokensUndelegated` | `serviceProvider`, `verifier`, `delegator`, `tokens`, `shares` | | `delegated-tokens-withdrawn` | `DelegatedTokensWithdrawn` | `serviceProvider`, `verifier`, `delegator`, `tokens` | | `delegation-slashed` | `DelegationSlashed` | `serviceProvider`, `verifier`, `tokens` | Every response gives you `block_num`, `log_index`, `tx_hash`, and the decoded fields. Addresses arrive as proper `0x…` (already un-padded from their 32-byte topic form). Numeric fields — including `uint256` `tokens`/`shares` amounts — come back as **decimal strings** , deliberately, so they survive the JSON round-trip without getting mangled by JavaScript’s 53-bit `Number`. Parse them with your bigint library of choice. > One honest caveat: `DelegationFeeCutSet` isn’t in the set yet — it carries a `uint8 indexed` parameter that needs separate topic handling, so it was left out of the v0 cut to keep every event on the same projection shape. On the list. * * * ## How to query it Every event endpoint takes the same parameters: - `from_block` / `to_block` — **required** , span ≤ 100,000 blocks. - `limit` — optional, default 100, max 1,000. - Optional **indexed-address filters** by field name: `serviceProvider`, `verifier`, `delegator`. These are matched cheaply against `topic1..topic3` _before_ decoding, so filtering by them is essentially free. ### All delegations to one indexer curl “[https://camp.cargopete.com/v1/horizon/tokens-delegated\](https://camp.cargopete.com/v1/horizon/tokens-delegated%5C) ?serviceProvider=0xYOUR\_INDEXER\_ADDRESS\ &from\_block=466900000&to\_block=466950000&limit=100” { “event”: “TokensDelegated”, “count”: 2, “events”: [{ “block\_num”: 466948210, “log\_index”: 14, “tx\_hash”: “0x…”, “serviceProvider”: “0x…”, “verifier”: “0x…”, “delegator”: “0x…”, “tokens”: “5000000000000000000000”, “shares”: “4987120000000000000000” }] } ### Every slashing event in a window curl “[https://camp.cargopete.com/v1/horizon/provision-slashed\](https://camp.cargopete.com/v1/horizon/provision-slashed%5C) ?from\_block=466900000&to\_block=466950000&limit=100” Pair it with `delegation-slashed` to see how a slash split across the provision and its delegation pool. ### A delegator’s full footprint Filter `tokens-delegated`, `tokens-undelegated`, and `delegated-tokens-withdrawn` by `delegator=0x…` to reconstruct a delegator’s lifecycle across any indexer. * * * ## When the canned endpoints aren’t enough: raw SQL The decoded endpoints cover the common questions, but Horizon analytics often means _aggregation_ — “total tokens delegated per day”, “top 10 most-slashed provisions”. For that there’s `POST /v1/sql`: a guarded DataFusion `SELECT` straight against the indexed `logs` table, with the same decode UDFs the endpoints use internally. curl -X POST [https://camp.cargopete.com/v1/sql](https://camp.cargopete.com/v1/sql) \ -H “Content-Type: text/plain” \ –data ‘SELECT date\_trunc(’“'”‘day’“'”‘, timestamp) AS day, COUNT(\*) AS delegations FROM “\_/arbitrum\_one@2.0.0”.logs WHERE block\_num BETWEEN 466900000 AND 466990000 AND address = X’“'”‘00669a4cf01450b64e8a2a20e9b1fcb71e61ef03’“'”’ AND topic0 = evm\_topic(‘"’“‘TokensDelegated(address,address,address,uint256,uint256)’”‘"’) GROUP BY 1 ORDER BY 1’ The UDFs available inside SQL: - `evm_topic('Sig(types)')` — derive a `topic0` from a canonical event signature. - `evm_decode_log(topic1, topic2, topic3, data, 'Sig(...)')` — decode a log row into a typed struct; access fields with `d['fieldName']`. - plus `evm_decode_params` / `evm_encode_params` / `evm_decode_type` / `evm_encode_type` for calldata work. The guard rails: `SELECT`-only, every query **must** reference `block_num` (so the scan is always bounded), a hard `LIMIT 1000` is injected if you omit it, 8s server-side timeout, and no comments/multi-statements/DDL/file-IO. `GET /v1/sql` returns the full self-describing contract — tables, UDFs, and a worked example. There’s also a **Dune-style SQL playground** in the browser at [sql playground · camp](https://camp.cargopete.com/explore/sql) if you’d rather click than curl, and a decoded Horizon timeline (with severity accents on slashing events) at [graph horizon · camp](https://camp.cargopete.com/explore/horizon). * * * ## How it works under the hood camp is the public Vercel gateway in front of a self-hosted **Amp** node. Amp is the interesting bit: it indexes raw chain data into compacted parquet and ships SQL-native EVM decoding (`evm_decode_log`, `evm_topic`, even `eth_call`-in-SQL) as DataFusion UDFs. So “decoded Horizon tables” aren’t a bespoke ETL pipeline — they’re a parameterised query against `logs`, resolved at request time. ```auto client │ ▼ camp.cargopete.com edge: TLS · DDoS · CDN response cache │ ▼ Cloudflare tunnel private link to the origin │ ▼ nginx shared-secret auth + per-IP rate limit (Redis) │ ▼ ampd (Arbitrum One) parquet on local SSD, compactor active, indexing at tip ``` Every public endpoint maps to a **single bounded SQL query**. Block-range, address, and topic filters are enforced server-side, so the chain stays the bottleneck rather than the gateway. Finalized ranges are edge-cached for an hour; near-tip queries for five seconds. **Data freshness:** the indexed window rebuilds forward from **2026-05-27** (a clean cutover after an ampd engine upgrade whose metadata schema wasn’t downgrade-safe) and grows ~24h every calendar day until it caps at a rolling ~30 days. Live depth is on every `/v1/status` response (`history_seconds`, `earliest_indexed_at`), so you can always check coverage before you query. * * * ## Fair use It’s a community service offered free, with no SLA. The contract, identical for everyone: | | | | --- | --- | | Max block span per request | 100,000 | | Max rows per response | 1,000 | | Server-side query timeout | 8 s | | Rate limit per IP | 30 / min · 500 / hour | | Edge cache | 1 h finalized · 5 s near tip | The limits are calibrated so a normal dashboard or bot has plenty of headroom while abuse hits the wall first. Work _with_ the cache and the rate limit, not around them. If you’re building something that needs chain data at a guaranteed latency, please run your own node — which brings us to: ## Run your own camp is one deployment of a repeatable pattern. The dataset config, the indexer, and this gateway are all open. Clone Amp, run `ampd solo` against your own Arbitrum RPC, drop the gateway in front, and you’ve got your own ungated node on a small VPS or a home server. No permission required, no rate limit but your own. * * * ## What’s next (and where this forum comes in) The decoded-protocol surface today is Graph Horizon (12 events) and Uniswap V3 (swap/mint/burn). On the roadmap: anonymous tokens for higher per-user limits, CSV / Arrow IPC export, and CDC-style streaming/webhooks. What I’d genuinely like input on from this community: - **Which Horizon events or aggregations are missing?** `DelegationFeeCutSet` is already queued — what else would you actually use? Per-indexer delegation time-series? Slashing leaderboards? A `/v1/horizon/provision/{indexer}` rollup? - **Is tip-freshness or history depth the bigger constraint** for your use case? The rolling-30d window is a deliberate trade-off; happy to revisit if there’s demand for deeper backfill of Horizon specifically. Bug reports, feature requests, and “this query returned something weird” reports all welcome at [Issues · lodestar-team/camp · GitHub](https://github.com/lodestar-team/camp/issues). * * * _Built on Amp. MIT-licensed gateway. Not affiliated with The Graph core teams — just a community node pointed at the data this forum cares about._ ---
**Author:** ![AxiomaticAardvark](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.thegraph.com/axiomaticaardvark/32/2935_2.png) [@AxiomaticAardvark](https://forum.thegraph.com/u/AxiomaticAardvark)\ **Post date:** [May 29, 2026, 1:03pm UTC](https://forum.thegraph.com/t/camp-free-tip-fresh-decoded-graph-horizon-data-on-arbitrum-one/6980/2 "2026-05-29T13:03:25Z")
more resources: camp itself - [https://engine.camp/](https://engine.camp/) launch post - [engine.camp is live: a free, tip-fresh data engine for Arbitrum One](https://cargopete.substack.com/p/enginecamp-is-live-a-free-tip-fresh) intro to camp - [camp: A Free Decoded Arbitrum API Built on a Self-Hosted Amp Node — Lodestar Blog](https://www.lodestar-dashboard.com/blog/camp-free-amp-api-arbitrum) camp deep dive - [camp Deep Dive: Decoded Protocol Data, Raw SQL, and the Flight Shim — Lodestar Blog](https://www.lodestar-dashboard.com/blog/camp-deep-dive)