Extract reth-erc8004-indexer into standalone Helm chart with discovery fallback

[bussyjd]

Summary

Wire the reth-erc8004-indexer into obol network install ethereum --mode archive as a drop-in reth image swap with ERC-8004 ExEx indexing, plus a 3-tier discovery client for downstream consumers (autoresearch, etc.).

Context

The reth-erc8004-indexer was extracted from PR #288 (Oisin's review: standalone Rust, not wired into the stack). The binary is compiled as reth ([[bin]] name = "reth" in Cargo.toml) — it IS reth with an ExEx bolted on. This means it's a drop-in image swap in the existing ethereum-helm-charts/ethereum-node chart, not a separate Helm chart.

Design

When --execution-client reth --mode archive is specified, the helmfile swaps the upstream ethereum/reth image for ghcr.io/obolnetwork/reth-erc8004-indexer, exposes the indexer API port (3400), and adds a SQLite PVC.

obol network install ethereum --mode archive
  |
  +-- executionClient: reth (default)
  +-- mode: archive
  |
  +-- helmfile renders:
      reth:
        image:
          repository: ghcr.io/obolnetwork/reth-erc8004-indexer
          tag: v0.1.0
        extraPorts:
          - name: indexer-api
            containerPort: 3400

CLI behavior

# Default (unchanged)
obol network install ethereum
# -> reth full sync, no indexer

# Archive mode with ERC-8004 indexing
obol network install ethereum --mode archive
# -> reth-erc8004-indexer image, ExEx enabled, API on :3400

# Archive + non-reth client (indexer N/A)
obol network install ethereum --mode archive --execution-client geth
# -> geth archive sync, no indexer (warn: ERC-8004 indexing only with reth)

Implementation Phases

Phase 1: Template plumbing (unblocks everything)

File	Change
internal/embed/networks/ethereum/values.yaml.gotmpl	Add Mode field: @enum full,archive @default full
internal/embed/networks/ethereum/helmfile.yaml.gotmpl	Conditional image swap when mode=archive + executionClient=reth
internal/embed/networks/ethereum/templates/pvc.yaml	Optional indexer PVC (indexer-data, 10Gi) when archive mode

CLI --mode flag is auto-generated from the @enum annotation -- zero Go code needed.

Phase 2: Indexer image CI (parallel)

File	Change
reth-erc8004-indexer/	Restore Rust source from extracted commit
Dockerfile.reth-erc8004-indexer	Restore
.github/workflows/docker-publish-reth-indexer.yml	Build + publish + Trivy scan

Phase 3: Discovery client (parallel)

File	Change
internal/discovery/discovery.go	DiscoveryClient interface + FallbackClient
internal/discovery/reth.go	Client for local indexer API (:3400)
internal/discovery/basescan.go	Client for BaseScan ERC-8004 metadata
internal/discovery/eightkcan.go	Client for 8004scan.io
internal/discovery/*_test.go	Per-client unit + fallback integration tests

Phase 4: Wire into autoresearch

• Auto-detect indexer when deployed (archive mode)
• Fallback: no indexer -> BaseScan -> 8004scan.io
• Integration test: register -> index -> discover -> probe via x402

Dependency graph

Phase 1 (template) --+
Phase 2 (CI)       --+--> Phase 4 (wire autoresearch)
Phase 3 (discovery) -+

Phases 1, 2, 3 run in parallel.

3-Tier Discovery Architecture

Priority 1: Internal Reth Indexer (self-hosted, real-time)
    |  reth-indexer:3400
    |  Latency: <100ms, block-level freshness
    |  Cost: runs archive Base L2 node (~500GB disk)
    v if unavailable
Priority 2: BaseScan API (hosted, reliable)
    |  api.basescan.org -- ERC-8004 metadata natively supported
    |  Latency: <500ms, free tier 5 calls/sec
    v if no API key
Priority 3: 8004scan.io (community, best-effort)
    |  No key required, minutes behind chain
    v if all unavailable
    Error: no discovery backend

Discovery Client Interface

type DiscoveryClient interface {
    ListAgents(ctx context.Context, opts ListOptions) ([]Agent, error)
    SearchAgents(ctx context.Context, query string, limit int) ([]Agent, error)
    GetAgent(ctx context.Context, chainID uint64, tokenID string) (*Agent, error)
    Health(ctx context.Context) error
}

Test Plan

Rust unit tests

• storage.rs: SQLite CRUD, pagination, search
• indexer.rs: event log parsing, reorg handling
• api.rs: response shape matches 8004scan contract

Go tests

• Discovery client per-tier unit tests
• FallbackClient integration (priority order, cache TTL)
• Template rendering: --mode archive produces correct image/port/PVC

Helm tests

• test-api.yaml: health + stats endpoints

Integration

• Register agent on-chain -> indexer picks up -> coordinator discovers -> x402 probe

Acceptance Criteria

1. obol network install ethereum --mode archive deploys reth-erc8004-indexer image
2. Indexer API serves on :3400 with 8004scan-compatible responses
3. obol network install ethereum (no --mode) unchanged -- upstream reth image
4. Discovery fallback works: indexer -> BaseScan -> 8004scan
5. CI builds and publishes indexer image to ghcr.io