feat(foreign-tx): wire svm chains into node

[frolvanya]

Connects config -> inspector -> signing, so a node actually serves Solana and
Fogo verification requests. Before this PR the node still rejects them.

• node config: fogo section added (solana already existed);
• verify_foreign_tx: one typed inspector fan-out per chain
  (SolanaInspector / FogoInspector, so a slot mix-up is a compile error)
  and dispatch arms that replace the old
  bail!("ForeignChainRpcRequest::Solana is unsupported"); tests pin that
  each chain's config feeds its own slot;
• health check: golden check + network-fingerprint probe for both chains;
• operator docs, localnet templates and user-config gain both chains.

Every genesis hash committed here was read from a live node:
solana mainnet 5eykt4UsFv8P8NJdTREpY1vzqKqZKvdpKuc147dw2N9d
solana devnet EtWTRABZaYq6iMfeYKouRu166VU2xqa1wcaWoxPkrZBG
fogo mainnet CDLtwKnaCoK157uaHQDj4fHu72AyD2519Cphmpiq6hvT
fogo testnet 9GGSFo95raqzZxWqKM5tGYvJp5iv4Dm565S4r8h5PEu9

Verified with the config tester against live endpoints (mainnet and testnet both
pass), including a negative check: pointing the Solana entry at Fogo's URL fails
with "chain id mismatch", so the check is not passing vacuously.

[Copilot]

Pull request overview

Wires SVM-based foreign chain verification (Solana and Fogo) end-to-end in the MPC node, connecting operator config through inspector fan-out into verify_foreign_tx, and extending health-check/config-tester/docs so nodes can validate and serve these chains instead of rejecting them.

Changes:

• Adds typed Solana/Fogo inspector fan-out and request dispatch for verify_foreign_tx (plus config parsing / wiring tests).
• Extends foreign-chain health checks with SVM genesis-hash fingerprint probing and golden vectors for Solana/Fogo.
• Updates operator/localnet documentation and templates to include Solana/Fogo configuration and Solana localnet request args.

Reviewed changes

Copilot reviewed 17 out of 17 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
docs/running-an-mpc-node-in-tdx-external-guide.md	Adds Solana/Fogo foreign_chains examples for testnet/mainnet deployments.
docs/localnet/mpc-configs/config.yaml.template	Adds Solana config to localnet YAML template (needs follow-up for Fogo + comment correctness per PR comments).
docs/localnet/mpc-config.template.toml	Adds Solana config to localnet TOML template (needs follow-up for Fogo + comment correctness per PR comments).
docs/localnet/localnet.md	Documents how to generate a fresh Solana signature and run a Solana verify_foreign_transaction call.
docs/localnet/args/verify_foreign_tx_solana.json	Adds a localnet request fixture for Solana verification (with placeholder tx id).
docs/foreign-chain-transactions.md	Documents SVM fingerprint probing (getGenesisHash) and tabulates Solana/Fogo genesis hashes.
deployment/cvm-deployment/user-config.toml	Adds Solana/Fogo config blocks for CVM deployment user config (testnet + commented mainnet variant).
crates/node/src/web.rs	Extends debug/config surface to report configured provider counts for Fogo.
crates/node/src/tests/foreign_chain_configuration.rs	Ensures foreign chain configuration setup includes the new fogo slot.
crates/node/src/providers/verify_foreign_tx/sign.rs	Adds Solana/Fogo dispatch to SVM inspectors for request execution.
crates/node/src/providers/verify_foreign_tx.rs	Adds Solana/Fogo inspectors to the node wiring and tests to pin correct config-to-slot mapping.
crates/node-config/src/foreign_chains.rs	Adds fogo to config model and parsing/validation tests.
crates/foreign-chain-health-check/src/probe.rs	Implements provider probing for Solana and Fogo using their inspectors.
crates/foreign-chain-health-check/src/lib.rs	Runs SVM checks for Solana/Fogo instead of skipping them as “not yet supported”.
crates/foreign-chain-health-check/src/golden.rs	Introduces SVM golden vectors (genesis hash) for mainnet/testnet Solana/Fogo.
crates/foreign-chain-health-check/src/checks.rs	Adds check_svm that validates chain identity via canonicalized genesis hash.
crates/foreign-chain-config-tester/README.md	Updates config tester docs to reflect SVM chain checks and expected output.

---

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[claude]

Pull request overview

This PR connects the already-merged SVM inspector to the rest of the node so that Solana and Fogo verification requests are actually served instead of rejected. It adds a fogo node-config section (solana already existed), fills the solana/fogo inspector slots in ForeignChainInspectors, replaces the bail!("ForeignChainRpcRequest::Solana is unsupported") arm with a shared execute_svm_request helper used by both SVM chains, and wires both chains into the two health-check routes (golden identity check + network-fingerprint probe). Operator-facing templates and docs gain both chains, with every genesis hash reportedly read back from a live node.

Changes:

• mpc-node-config: new fogo: Option<ForeignChainConfig> section, mapped to dtos::ForeignChain::Fogo in all_configured_chains, so it feeds registration, validation and the whitelist verifier like every other chain.
• mpc-node: solana/fogo FanOut<SvmInspector<HttpClient, _>> slots built through with_http_client; sign.rs dispatches both variants through one generic execute_svm_request; /debug provider counts gain fogo.
• foreign-chain-health-check: SvmVector golden entries (mainnet + testnet), check_svm genesis-hash identity check, run_svm fan-out, and getGenesisHash probe arms for Solana and Fogo.
• Docs/config: user-config.toml, TDX guide, localnet templates and a new verify_foreign_tx_solana.json fixture; the fingerprint tables in docs/foreign-chain-transactions.md are updated and the stale "solana … has no inspector" passage is corrected.

Reviewed changes

Per-file summary

File	Description
crates/foreign-chain-config-tester/README.md	Describes SVM chains as identity-checked rather than replayed; sample output gains a solana row.
crates/foreign-chain-health-check/src/checks.rs	New check_svm<Chain>: compares the provider's canonicalized getGenesisHash against the golden value.
crates/foreign-chain-health-check/src/golden.rs	SvmVector type plus solana/fogo genesis hashes for mainnet and testnet; base58 decode test extended.
crates/foreign-chain-health-check/src/lib.rs	run_svm per-provider loop; solana moves out of the "not yet supported" block, fogo added; chain-list test updated.
crates/foreign-chain-health-check/src/probe.rs	Fingerprint-probe arms for ForeignChain::Solana and ForeignChain::Fogo; TODO comment narrowed.
crates/node-config/src/foreign_chains.rs	fogo config section, DTO mapping, and a parse/validate test for it.
crates/node/src/providers/verify_foreign_tx.rs	solana/fogo inspector slots; new tests pinning that each config feeds only its own slot.
crates/node/src/providers/verify_foreign_tx/sign.rs	Solana/Fogo dispatch arms delegating to the new generic execute_svm_request.
crates/node/src/tests/foreign_chain_configuration.rs	fogo: None added to the exhaustive ForeignChainsConfig literal.
crates/node/src/web.rs	fogo provider count in the debug endpoint; Fogo URL added to the redaction assertions.
deployment/cvm-deployment/user-config.toml	Testnet solana (devnet) + fogo sections, and the commented mainnet variants.
docs/foreign-chain-transactions.md	Fingerprint tables gain solana/fogo; corrects the passage claiming Solana has no inspector.
docs/localnet/args/verify_foreign_tx_solana.json	New request fixture: placeholder tx_id, rent-sysvar AccountState extractor.
docs/localnet/localnet.md	Solana walkthrough, including a snippet that patches in a fresh finalized signature.
docs/localnet/mpc-config.template.toml, docs/localnet/mpc-configs/config.yaml.template	Localnet solana section with the mainnet genesis hash.
docs/running-an-mpc-node-in-tdx-external-guide.md	Solana/Fogo blocks for the testnet and mainnet config examples.

Findings

Blocking (must fix before merge):

• crates/node/src/providers/verify_foreign_tx/sign.rs:140 — the dispatch arms are the exact hazard the PR guards against one file over (verify_foreign_tx.rs:157: "a config.solana/config.fogo swap still type-checks"), but nothing pins them. execute_svm_request is generic over Chain, so Solana(request) => … self.inspectors.fogo … compiles cleanly, and the consequence is worse than a config-slot swap: every node substitutes identically, so FanOut's cross-provider agreement check cannot catch it and the network signs a ForeignTxSignPayloadV1 asserting a Solana transaction over data read from Fogo. Please pin request-variant → inspector-slot the same way you pinned config → slot. A cheap seam is to extract the selection, e.g.

  impl ForeignChainInspectors<HttpClient> {
      fn svm(&self, chain: dtos::ForeignChain) -> Option<&FanOut<SvmInspector<HttpClient, ???>>> { … }
  }

  — or, since the two slots have different Chain types, a small #[cfg(test)] assertion that each arm reaches the fan-out built from the corresponding config (two mock SVM endpoints answering distinguishable getTransaction payloads works, mirroring crates/e2e-tests/tests/foreign_chain_tx_validation.rs).

• crates/foreign-chain-health-check/src/checks.rs:218, crates/foreign-chain-health-check/src/lib.rs:102, crates/foreign-chain-health-check/src/probe.rs:111 — the new health-check code paths ship untested, against engineering-standards.md §Add tests ("if the change was reverted, these tests would fail"). Concretely, all of these survive the current suite: stubbing check_svm to Ok(()), dropping the got != expected comparison, swapping golden.solana ⇄ golden.fogo in run_svm calls, or reverting the two probe arms to ProbeNotImplemented. golden.rs:242 only proves the constants are 32 base58 bytes — it cannot catch a mainnet/devnet or solana/fogo mix-up. The sibling check_sui landed with check_sui__should_pass_when_provider_is_on_the_expected_network and check_sui__should_fail_when_chain_id_differs (checks.rs:385, checks.rs:400), and probe.rs already tests every other wired chain (probe_all_providers__should_report_every_evm_chain_on_its_expected_network_as_healthy). httpmock is in scope in both modules and getGenesisHash is a single-value JSON-RPC response, so the equivalents are a few lines each.

Non-blocking (nits, follow-ups, suggestions):

• docs/localnet/localnet.md:507 — the snippet rewrites the tracked docs/localnet/args/verify_foreign_tx_solana.json in place, so following the walkthrough leaves the operator's working tree dirty with a mainnet signature that goes stale anyway. Suggest leaving the patched copy in /tmp and pointing the call at it:

  jq --arg tx "$TX_HEX" '.request.request.Solana.tx_id = $tx' \
    docs/localnet/args/verify_foreign_tx_solana.json > /tmp/verify_foreign_tx_solana.json

  with file-args /tmp/verify_foreign_tx_solana.json in the near contract call-function line below.
• crates/foreign-chain-health-check/src/golden.rs:34, lib.rs:322, checks.rs:215 — the same rationale ("SVM providers prune historical transactions, so identity is checked instead") is restated in three doc comments within one crate. Per engineering-standards.md §Write helpful code comments, keep it at the definition (check_svm) and let the other two be intra-doc links to it.
• crates/foreign-chain-health-check/src/checks.rs:218 — for SVM, check_svm is now byte-for-byte the same assertion the fingerprint probe already makes (getGenesisHash, canonicalized, compared), unlike check_sui, which additionally inspects a checkpointed transaction. Given TODO(#3969) plans to retire the golden route, it may be worth deciding now whether the SVM golden entries earn their keep or whether the probe alone should cover these chains.
• deployment/cvm-deployment/user-config.toml:286 — Fogo ships with a single public provider on both networks, so its fan-out degenerates to one source and FanOut's cross-provider agreement check is vacuous for that chain (every other chain in the template has 2–4). A short comment saying that is intentional until a second Fogo endpoint exists would save operators the question.

⚠️ Issues found

[frolvanya]

@claude review

[claude]

Pull request overview

Node-wiring layer of the SVM stack: connects operator config to inspector fan-out to verify_foreign_tx dispatch, so a node actually serves Solana and Fogo verification requests instead of bail!-ing on them. Adds the missing fogo config section, fills the solana/fogo slots in ForeignChainInspectors, routes both request variants through a shared generic execute_svm_request, and wires both chains into the two health-check routes (golden identity check + fingerprint probe). Docs, localnet templates and the CVM user-config gain both chains.

Since the last round the health-check test gap was closed properly: check_svm, run_svm and both probe arms now have tests that would fail if the wiring were reverted or crossed. The remaining problem is the other direction — making Solana supported invalidated three pre-existing tests built around Solana being unsupported, and the PR re-pointed them at Sui instead of deleting them. Cargo test: other is currently red.

Changes:

• mpc-node-config: fogo section, mapped to dtos::ForeignChain::Fogo in all_configured_chains (and so iter_chains, registration, validation).
• mpc-node: solana/fogo FanOut<SvmInspector<HttpClient, _>> slots; sign.rs dispatches both variants through one generic execute_svm_request; /debug counts gain fogo.
• foreign-chain-health-check: SvmVector golden entries, check_svm, run_svm, getGenesisHash probe arms, plus tests for each.
• Docs/config: user-config.toml, TDX guide, localnet templates, verify_foreign_tx_solana.json fixture, Solana localnet walkthrough.

Reviewed changes

Per-file summary

File	Description
crates/foreign-chain-config-tester/README.md	SVM chains described as identity-checked, not replayed; sample output gains a solana row.
.../health-check/src/checks.rs	New check_svm<Chain> comparing canonicalized getGenesisHash to the golden value, plus pass/fail tests.
.../health-check/src/golden.rs	SvmVector plus solana/fogo genesis hashes for mainnet and testnet; base58 test extended.
.../health-check/src/lib.rs	run_svm per-provider loop; solana out of the "not yet supported" block, fogo added; cross-chain vector test.
.../health-check/src/probe.rs	Probe arms for Solana/Fogo, must_put_chain slots, healthy/wrong-network tests; ProbeNotImplemented tests re-pointed at Sui.
crates/node-config/src/foreign_chains.rs	fogo config section, DTO mapping, parse/validate test.
crates/node/src/providers/verify_foreign_tx.rs	solana/fogo inspector slots and tests pinning each config to its own slot.
crates/node/src/providers/verify_foreign_tx/sign.rs	Solana/Fogo dispatch arms delegating to the new generic execute_svm_request.
crates/node/src/tests/{foreign_chain_configuration,verify_foreign_tx_gating}.rs	fogo: None in exhaustive ForeignChainsConfig literals.
crates/node/src/web.rs	fogo provider count in /debug; Fogo URL added to the redaction assertions.
deployment/cvm-deployment/user-config.toml	Testnet solana (devnet) + fogo sections and the commented mainnet variants.
docs/foreign-chain-transactions.md	Probe and fingerprint-value tables gain solana/fogo; "which chains read the field" paragraph rewritten.
docs/localnet/args/verify_foreign_tx_solana.json	New fixture: placeholder tx_id, rent-sysvar AccountState extractor.
docs/localnet/localnet.md	Solana walkthrough; snippet writes the patched copy to /tmp.
docs/localnet/mpc-config.template.toml, docs/localnet/mpc-configs/config.yaml.template	Localnet solana section with the mainnet genesis hash.
docs/running-an-mpc-node-in-tdx-external-guide.md	Solana/Fogo blocks for the testnet and mainnet config examples.

Findings follow in the next comment.

[claude]

Findings (continued from the previous comment)

Blocking (must fix before merge):

• crates/foreign-chain-health-check/src/probe.rs:813 and :838 — the two ProbeNotImplemented tests were re-pointed from Solana to Sui, but Sui has a probe: the ForeignChain::Sui => probe_chain(... SuiInspector ...) arm sits directly above the _ => catch-all this PR edits. With CLOSED_PORT_URL, prepare_sui builds a GrpcSuiClient fine and the connection then fails, so the status is Unreachable, not ProbeNotImplemented — which is exactly what the adjacent probe_all_providers__should_report_an_unreachable_sui_provider asserts for the identical config. Both re-pointed assertions are now false.

  Why no good substitute existed: after this PR no ForeignChainsConfig field is left without a probe — Ton is the only unprobed chain and it has no config slot (must_put_chain panics on it). So probe_all_providers__should_report_a_chain_with_no_fingerprint_probe_as_not_implemented is no longer expressible and should be deleted rather than re-pointed. probe_all_providers__should_report_every_configured_chain_under_its_own_chain only needs two chains keyed separately, so keep Sui there and assert what it actually produces:

  assert_eq!(
      must_status_of(&report, ForeignChain::Sui, "publicnode"),
      ProviderStatus::Unreachable
  );

• crates/foreign-chain-health-check/src/lib.rs:489 — check_all_providers__should_skip_configured_but_unsupported_chains still configures solana (rpc_url https://rpc.example.com) and asserts Status::Skipped(reason) containing "not yet supported", but this PR deletes the only mark_skipped(..., "not yet supported by the node", ...) call in the crate. golden.solana is Some for mainnet, so run_svm now runs for real: the test fails with Status::Failed(...) and issues a live outbound HTTP request from a unit test. Nothing is "configured but unsupported" any more — delete the test.

  Together these two account for the red Cargo test: other check; worth confirming it is green before merge rather than treating it as pre-existing.

• docs/foreign-chain-transactions.md:574 — stale sentence, now contradicted by the table two lines below it: "Every chain with an inspector is probed, each by the RPC below. solana has none, so it ignores expected_network_fingerprint." The PR adds | solana, fogo | getGenesisHash | to that very table. Doc drift is review-blocking per CLAUDE.md; the second sentence can just be dropped, since every chain with an inspector is now probed.

• docs/foreign-chain-transactions.md:747 — the replacement paragraph lists the chains that read expected_network_fingerprint as "starknet, bitcoin, aptos, the EVM chains and the SVM chains today" and omits sui, which has had a GetServiceInfo probe since before this PR and appears in the probe table above. A Sui operator would conclude the field is ignored for their chain, when leaving it unset actually reports every Sui provider as MissingExpectedFingerprint.

• crates/node/src/providers/verify_foreign_tx/sign.rs:219 — still open from the previous round: the request-variant to inspector-slot mapping is unpinned. execute_svm_request is generic over Chain, so Solana(request) => ... self.inspectors.fogo ... type-checks, and unlike a config-slot swap every node substitutes identically, so FanOut's cross-provider agreement cannot catch it. Not repeating the rationale — see the earlier comment for the suggested seam.

Non-blocking (nits, follow-ups):

• crates/foreign-chain-health-check/src/probe.rs:160 — // nothing to probe them it. is a half-finished edit; it also fits on one line: // TODO(#4003): Ton has no inspector to probe it with.
• crates/foreign-chain-health-check/src/lib.rs:535 — "ethereum" is appended to the expected list, but it is already the first entry of that same list; the loop just checks the row twice.
• crates/foreign-chain-health-check/src/checks.rs:218 — the Chain parameter on check_svm is decorative: network_fingerprint/canonical_fingerprint are implemented for SvmInspector<Client, Chain> with only Chain: Send + Sync and never touch it, so check_svm::<Solana> and check_svm::<Fogo> are the same function; only expected_genesis_hash separates the chains. Fine in itself, but it reads as type-level protection it does not give — drop the parameter or say so in the doc comment.
• crates/foreign-chain-health-check/src/checks.rs:386 and lib.rs:451 — mock_genesis_hash is defined verbatim twice and is byte-identical to the pre-existing probe.rs::mock_fingerprint. None of the three asserts the method name, so a probe pointed at the wrong RPC method would still pass.
• crates/foreign-chain-health-check/src/lib.rs:428 — config_at differs from the existing config_with_provider only in the rpc_url; consider parameterizing the existing helper.
• crates/foreign-chain-config-tester/README.md:52 — the sample output gains a solana row but not fogo, and the totals move to 5 passed; inconsistent either way if the sample is meant to show a fully-configured node.
• Previously raised, still open: the "SVM providers prune historical transactions" rationale restated in three doc comments in one crate (golden.rs:34, lib.rs:333, checks.rs:215), and Fogo shipping with a single public provider in deployment/cvm-deployment/user-config.toml, which makes its fan-out agreement check vacuous.

⚠️ Issues found

[frolvanya]

@claude review

[claude]

Pull request overview

Node-wiring layer of the SVM stack: connects operator config → inspector fan-out → verify_foreign_tx dispatch, so a node actually serves Solana and Fogo verification requests instead of bail!-ing on them. Adds the missing fogo config section, fills the solana/fogo slots in ForeignChainInspectors, routes both request variants through a shared generic execute_svm_request, and wires both chains into the two health-check routes (golden identity check + fingerprint probe). Docs, localnet templates and the CVM user-config gain both chains.

Since the last round every health-check finding is resolved: the ProbeNotImplemented test is deleted rather than re-pointed at Sui (which has a probe and would report Unreachable); should_report_every_configured_chain_under_its_own_chain now uses Bitcoin and asserts Unreachable, matching what starknet_only + CLOSED_PORT_URL already produces at probe.rs:595; should_skip_configured_but_unsupported_chains is replaced with an Ethereum-on-testnet skip (TESTNET.ethereum is None, so nothing reaches the network); the duplicated "ethereum" entry is gone; the localnet snippet writes to /tmp; and the foreign-chain-transactions.md passages are consistent with the new probe table.

Changes:

• mpc-node-config: fogo section, mapped to dtos::ForeignChain::Fogo in all_configured_chains (and so iter_chains, registration, validation).
• mpc-node: solana/fogo FanOut<SvmInspector<HttpClient, _>> slots; sign.rs dispatches both variants through one generic execute_svm_request; /debug counts gain fogo.
• foreign-chain-health-check: SvmVector golden entries, check_svm, run_svm, getGenesisHash probe arms, plus tests for each.
• Docs/config: user-config.toml, TDX guide, localnet templates, verify_foreign_tx_solana.json fixture, Solana localnet walkthrough.

Reviewed changes

Per-file summary

File	Description
crates/foreign-chain-config-tester/README.md	SVM chains described as identity-checked, not replayed; sample output gains a solana row.
crates/foreign-chain-health-check/src/checks.rs	New check_svm<Chain> comparing the canonicalized getGenesisHash to the golden value, plus pass/fail tests.
crates/foreign-chain-health-check/src/golden.rs	SvmVector plus solana/fogo genesis hashes for mainnet and testnet; base58 decode test extended.
crates/foreign-chain-health-check/src/lib.rs	run_svm per-provider loop; solana out of the "not yet supported" block, fogo added; cross-chain vector test; two pre-existing tests re-based onto Ethereum/testnet.
crates/foreign-chain-health-check/src/probe.rs	Probe arms for Solana/Fogo, must_put_chain slots, healthy/wrong-network tests; the ProbeNotImplemented test deleted, the "own chain" test moved to Bitcoin.
crates/node-config/src/foreign_chains.rs	fogo config section, DTO mapping, parse/validate test.
crates/node/src/providers/verify_foreign_tx.rs	solana/fogo inspector slots and tests pinning each config to its own slot.
crates/node/src/providers/verify_foreign_tx/sign.rs	Solana/Fogo dispatch arms delegating to the new generic execute_svm_request.
crates/node/src/tests/{foreign_chain_configuration,verify_foreign_tx_gating}.rs	fogo: None in the exhaustive ForeignChainsConfig literals.
crates/node/src/web.rs	fogo provider count in /debug; Fogo URL added to the redaction assertions.
deployment/cvm-deployment/user-config.toml	Testnet solana (devnet) + fogo sections and the commented mainnet variants.
docs/foreign-chain-transactions.md	Probe and fingerprint-value tables gain solana/fogo; the two stale ProbeNotImplemented / "no inspector" sentences removed.
docs/localnet/args/verify_foreign_tx_solana.json	New fixture: placeholder tx_id, rent-sysvar AccountState extractor.
docs/localnet/localnet.md	Solana walkthrough; the patched fixture is written to /tmp.
docs/localnet/mpc-config.template.toml, docs/localnet/mpc-configs/config.yaml.template	Localnet solana section with the mainnet genesis hash.
docs/running-an-mpc-node-in-tdx-external-guide.md	Solana/Fogo blocks for the testnet and mainnet config examples.

Findings

Blocking (must fix before merge):

• crates/node/src/providers/verify_foreign_tx/sign.rs:219 — unchanged from the previous two rounds, and now the only test gap left in the PR: the headline behaviour change (a node serves Solana/Fogo instead of bail!("ForeignChainRpcRequest::Solana is unsupported")) has no test that would fail if it were reverted, and the request-variant → inspector-slot mapping is unpinned. execute_svm_request is generic over Chain, so Solana(request) => … self.inspectors.fogo … type-checks; unlike a config-slot swap, every node substitutes identically, so FanOut's cross-provider agreement cannot catch it. Per engineering-standards.md §Add tests this needs coverage either way.

  The seam already exists and would close both halves at once: crates/e2e-tests/tests/foreign_chain_tx_validation.rs has one verify_<chain> helper per chain against an httpmock provider, all driven from verify_foreign_transaction__should_sign_all_supported_chains (:614). Adding verify_solana / verify_fogo with distinguishable getTransaction payloads pins each arm to its own fan-out. Note that configuring Solana in that cluster invalidates the "chain not in the foreign chain config" negative at :655, which currently uses Solana — it needs a chain that stays unconfigured (Fogo cannot be it if you add both).

Non-blocking (nits, follow-ups):

• crates/foreign-chain-health-check/src/probe.rs:298 — ANY_FINGERPRINT's doc comment ("For a chain with no probe: the value is never read, only whether it is set at all") is now false. Its one remaining use is Bitcoin in should_report_every_configured_chain_under_its_own_chain, and Bitcoin does have a probe: probe_chain canonicalizes the value via BitcoinInspector::canonical_fingerprint before use. The test passes only because the provider is unreachable, not because the value is unread.
• crates/foreign-chain-health-check/src/probe.rs:159 — with Solana and Fogo wired, every chain that has a ForeignChainsConfig slot now has a probe arm, so the _ => catch-all is unreachable through iter_chains() and ProviderStatus::ProbeNotImplemented is dead (its only test was correctly deleted here). Consider spelling the arm out as ForeignChain::Ton => … so that a future chain gaining a config slot without a probe is a compile error rather than a silent ProbeNotImplemented row. The comment also reads as a wrapped half-sentence and fits on one line.
• crates/foreign-chain-health-check/src/probe.rs:877 — "a cross-wired arm would compare Solana's against Fogo's" overstates what the test pins. SolanaInspector and FogoInspector differ only in the Chain marker, which neither network_fingerprint nor canonical_fingerprint reads, so swapping the inspector types between the two arms is unobservable; the expected fingerprint and the URL both come from the config slot, which chain already selects. What the test genuinely pins is that neither chain falls through to _ => ProbeNotImplemented — worth saying that instead. (The sibling comment in lib.rs:437, about a crossed golden vector binding, is accurate — that one really is the discriminator.)
• Previously raised, still open:
  • the "SVM providers prune historical transactions" rationale restated in three doc comments in one crate (golden.rs:33, lib.rs:333, checks.rs:215) — keep it at check_svm and intra-doc-link the other two;
  • mock_genesis_hash defined verbatim in both checks.rs:387 and lib.rs:447, and byte-identical to the pre-existing probe.rs::mock_fingerprint; none of the three asserts the JSON-RPC method name, so a probe pointed at the wrong method still passes;
  • lib.rs:431 — config_at differs from config_with_provider only in the rpc_url; parameterize the existing helper;
  • checks.rs:218 — the Chain parameter on check_svm is decorative (check_svm::<Solana> and check_svm::<Fogo> are the same function); it reads as type-level protection it does not provide;
  • crates/foreign-chain-config-tester/README.md:50 — the sample output gains solana but not fogo (and the totals move to 5 passed), inconsistent if the sample is meant to show a fully-configured node;
  • deployment/cvm-deployment/user-config.toml:286 — Fogo ships with a single public provider on both networks, so its fan-out degenerates to one source and the cross-provider agreement check is vacuous for that chain; every other chain in the template has 2–4. A one-line note that this is intentional until a second endpoint exists would save operators the question.

⚠️ Issues found