> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lasso.sh/llms.txt
> Use this file to discover all available pages before exploring further.

# Qualify historical RPC workloads

> Measured historical-state samples, known gaps, and a practical archive-workload acceptance path.

Test the exact historical methods, blocks and selectors your application needs.
A successful old header or log query does not prove that an upstream can serve
state at that block—or that customer routing will reach it.

## What we measured

On **September 20, 2026**, we sampled the production configuration from **one SJC
node**, source `89ade5b9be5745f09ee09f0c394223549e5f0085`. Direct upstream probes
ran from the investigator's network, not from Lasso's deployed nodes. This is
dated evidence, not a claim about a later deployment.

The study made **3,404 direct requests**, including reference acquisition and
retained-witness checks, without retries. Positive witnesses covered Ethereum,
Optimism, Unichain, Polygon, World, Base and Arbitrum at **1/7/30/365-day** timestamp
targets relative to `2026-09-20T19:21:18Z`. Tempo and Robinhood covered **1/7/30 days**;
the year target predates their observed block-1 history and is inapplicable.

State methods and logs used block-number and block-hash selectors; receipts used
transaction hashes. Results were checked against retained positive values and
block identities. Empty or null results did not establish coverage.

The inventory contained 118 HTTP profile-route slots and 92 distinct endpoint
authentication identities. Credentials initially matched 90 slots / 70 identities;
later matching reached 103 / 78 for supplemental runs only. A credential match
is not a successful probe. Unmatched or untested endpoints remain unknown.

## Direct upstream results

A **cell** is one witnessed chain × depth × selector × witness. A positive cell
has at least one anchored exact match, including reference-only matches. Missing
witnesses are excluded. These fractions are **not uptime or overall archive
coverage**. Primary profile routes are counted here; reserve results are separate.

| Method                      | Public positive | Public with 2+ families | Premium positive | Premium with 2+ families |
| --------------------------- | --------------: | ----------------------: | ---------------: | -----------------------: |
| `eth_call`                  |           56/68 |                   27/68 |            68/68 |                    60/68 |
| `eth_getCode`               |           54/68 |                   29/68 |            68/68 |                    60/68 |
| `eth_getStorageAt`          |           48/56 |                   26/56 |            56/56 |                    48/56 |
| `eth_getBalance`            |           40/40 |                   18/40 |            40/40 |                    40/40 |
| `eth_getTransactionReceipt` |           50/50 |                   24/50 |            50/50 |                    50/50 |
| `eth_getLogs`               |           54/54 |                   28/54 |            54/54 |                    54/54 |

“Families” are observed operator groupings, generally inferred from configuration,
with some endpoint-identity attribution. They do not prove independent
infrastructure, accounts or quotas. Positive endpoints with unknown attribution
must not be treated as proof of single-operator dependence. Receipt cells include
additional positive-log transaction witnesses at the same ages.

Download the [dated aggregate evidence](/files/historical-qualification-2026-09-20.json).

## Customer routing and remaining gaps

A separate **119-request production Premium check matched 54/56 positive call
cells** across the seven common chains. Arbitrum's day/hash call returned `-32000`
and month/number returned `-32603`, although a directly tested upstream answered
both witnesses. This study did **not** qualify customer routing through Public.
Direct capability and successful customer routing are separate acceptance gates.

Arbitrum Public direct calls matched **0/8** cells, with all three configured
primary endpoints tested; Premium matched **8/8** without a second corroborating
operator family. Positive Arbitrum logs did not establish historical state.
Only one of three Robinhood Public endpoints was credential-matched and tested;
the other two remain unknown.

**BSC, testnets and early-chain history remain unqualified.** Tempo and Robinhood
lack positive storage, balance, receipt and log witnesses here. World and
Arbitrum lack positive balance witnesses; Base lacks a month-depth positive-log
witness in the bounded search. These gaps are unknown coverage, not proof that a
method is unsupported. No sustained-load or availability guarantee follows.

## Qualify your application

1. Retain known positive values, block numbers/hashes and receipt/log identities
   for your actual contracts, ages, storage slots and log ranges. Test both
   selector forms your client uses; do not replace failures with easier witnesses.
2. For providers you own or bring to Lasso, compare direct upstream results with
   the exact Lasso endpoint and credential. For managed profiles, qualify that
   Lasso endpoint and credential directly; access to the managed upstreams is not
   required. Inspect [routing evidence](/cloud/observability) to confirm the service
   and effective profile; preserve failures separately.
3. Repeat from your deployment regions under representative load and an isolated
   test upstream failure. Measure correctness, latency, request volume and quota use.
   Keep the previous endpoint available during a [staged rollout](/cloud/adoption).