external-api.md

External API contract (pointer)

API-01–API-04 place owners under the contracts precedence rule. API-05 is the solo-mining generate path. API-06 is getnetworkhashps snapshot consistency. API-07 is the BIP22/BIP23 getblocktemplate extras the pinned corepc type does not model. API-08 is mainnet template operational gates. API-09 is submitheader. API-10 is GBT client-rule negotiation. API-11 is submitblock decode. API-12 is GBT proposal request parsing. API-13 is submitblock uncommitted witness fill. API-14 is Core v31 submitblock / GBT proposal duplicate vocabulary. API-15 is BIP22 reject-reason mapping. API-16 is GBT vbrequired always 0. API-17 is Core CheckWitnessMalleation reject reasons. API-18 is GBT coinbaseaux.flags. API-19 is prioritisetransaction dummy/fee_delta arity. API-20 is prioritisetransaction dust-output refusal. API-21 is GBT proposal / submitblock duplicate for reorged scripts-valid bodies. API-22 is getmininginfo omitting unset optional fields. API-23 is estimatesmartfee Core conf_target and estimate_mode gates. API-24 is generateblock Core txid/raw-tx parse errors. API-25 is getprioritisedtransactions modified_fee in satoshis.

Clauses

API-01: Single manifest dispatcher authority

• Owner: MANIFEST in crates/rpc/src/manifest.rs is the single source of truth for RPC, REST, and ZMQ external interfaces.
• A JSON-RPC method answers only when a non-Unimplemented row carries its name. Rows cover JSON-RPC, REST prefixes, and ZMQ topics, each with a status (Implemented, Deviation, Extension, Unimplemented) declared against Bitcoin Core 31.x.
• Methods marked Unimplemented return RpcError::MethodNotFound (code -32601).

API-02: Generated reference synchronization

• docs/rpc-reference.md is a generated file rendered directly from MANIFEST. It must not be edited by hand.
• Regenerate with: REGEN_RPC_REFERENCE=1 cargo test -p bitcoin-rs-rpc --test manifest_coverage -- --ignored regenerate_reference
• crates/rpc/tests/manifest_coverage.rs enforces that the checked-in reference matches the code manifest exactly on every CI run.

API-03: Error code mappings and wallet-free surface

• JSON-RPC failures map through RpcError (crates/rpc/src/error.rs): standard JSON-RPC codes (-32700, -32600..=-32603) and Core codes -3 (invalid type), -5 (not found), -8 (invalid parameter), -9 (not connected), -10 (initial download), -22 (deserialization), -25 (verify error), and -26 (verify rejected). Core -3, -8, and -22 messages are the Core text with no wrapper prefix (InvalidType, InvalidParameter, Deserialization).
• The node ships no wallet and holds no private key material. Methods that would reveal, import, create, or use private keys return RpcError::MethodNotFound. PSBT combination/finalization and descriptor utilities remain supported as they operate without private keys.

API-04: Read consistency and query budgeting

• Multi-record queries across chainstate use optimistic tip fencing or active-tip verification against BlockTree. If a reorg occurs during assembly, queries return 503 Service Unavailable rather than inconsistent data.
• Statistical and script index queries are bounded by QueryBudget to prevent memory exhaustion.

API-05: Solo-mining generate path

• Owner: MiningControl::generate in crates/mining/src/control.rs, implemented by MiningCoordinator::generate_blocks in crates/node/src/mining.rs.
• The operation assembles a fresh candidate (no GBT cache), solves it, then either submits through Chainstate::apply_block or dry-validates through Chainstate::validate_block (ARCH-07). Persistence and tip advancement are conditional on submit; validation is not.
• Each submitted block is a separate commit. An error after N successful submissions leaves those N blocks durable. Callers own retry after reading the applied tip. nblocks is not capped; the result vector grows one block at a time.
• generatetoaddress accepts only a network-valid address, uses mempool package selection, collects fees, and always submits.
• generateblock accepts an address or descriptor (require_checksum = false; a supplied checksum is verified). Ranged/multipath descriptors are refused. The transactions array is required (an explicit [] is coinbase-only). Listed order is kept, those fees are not added to the coinbase, 64-character hex is a mempool txid, and decoded raw transactions are included without mempool admission. Extra positional arguments are rejected. Transaction parse errors are API-24.

API-06: getnetworkhashps snapshot and invalid-height behavior

• Owner: MiningCoordinator::network_hash_ps in crates/node/src/mining.rs. Height resolution has one owner: resolve_hash_ps_start.
• The method takes the block-tree read lock, then loads one applied-tip snapshot. Height checks and the hash-rate walk use that snapshot and that locked tree, not a second tip load.
• nblocks (lookup) must be a positive count or -1 (since the last difficulty retarget). Otherwise the RPC is Core -8 (RpcError::InvalidParameter) with "Invalid nblocks. Must be a positive number or -1."
• height must be -1 (the snapshot tip) or an existing applied-chain height on that snapshot. Heights below -1, above the snapshot tip, or in range but unwalkable from that tip, are Core -8 with "Block does not exist at specified height", not a zero hash-rate.
• An empty chain with height == -1 estimates 0.0.
• getmininginfo's networkhashps is best-effort from the applied tip and does not use this RPC height-validation error path.

API-07: BIP22/BIP23 template extras

• Owner: MiningCoordinator::template_from_candidate in crates/node/src/mining.rs; JSON projection in crates/rpc/src/handlers/mining.rs render_block_template.
• Capabilities are the producer’s implemented set (proposal, longpoll). Client-advertised names are not echoed.
• submitold is present after a long-poll wait and omitted otherwise. workid is not emitted.
• On signet, the template carries signet in rules (mandatory) and signet_challenge. Other networks omit signet_challenge.

API-08: Mainnet template operational gates

• Owner: ensure_template_ready in crates/rpc/src/handlers/mining.rs.
• Template mode on mainnet requires at least one live peer (PeerTable) and that the node has left IBD (Context::is_initial_block_download). Failures are Core -9 (bitcoin-rs is not connected!) and -10 (bitcoin-rs is in initial sync and waiting for blocks...).
• Proposal mode does not apply these gates. Networks other than mainnet skip them, matching Core IsTestChain().

API-09: submitheader

• Owner: MiningCoordinator::submit_header in crates/node/src/mining.rs. RPC decodes the hex and projects the result; it does not admit headers.
• Decode failures (invalid hex, fewer than 80 bytes) are Core -22 (Block header decode failed). Extra bytes after an 80-byte header are ignored, matching Core DecodeHexBlockHeader.
• The previous header must already be in the block tree. Otherwise the RPC returns -25 (Must submit previous header (HASH) first).
• Admission uses accept_headers, the same consensus gate as inbound P2P headers. Duplicates succeed. Invalid headers return -25 with Core reject reasons (high-hash, bad-diffbits, time-too-old, time-too-new).
• Success is JSON null. Header-only admission does not apply the block or publish a mining generation.

API-10: GBT client-rule negotiation

• Owner: ensure_client_rules_for_template and ensure_client_supports_mandatory_rules in crates/rpc/src/handlers/mining.rs.
• Template mode requires the client to list segwit. On signet it also requires signet. Failures are Core -8 with Core's exact messages: getblocktemplate must be called with the segwit rule set (call with {"rules": ["segwit"]}) and getblocktemplate must be called with the signet rule set (call with {"rules": ["segwit", "signet"]}). Signet is checked first, matching Core v31.0 src/rpc/mining.cpp.
• These checks run before template assembly. Proposal mode skips them.
• After assembly, any remaining mandatory template rule the client omitted is Core -8: Support for 'NAME' rule requires explicit client support.

API-11: submitblock decode

• Owner: decode_submitted_block in crates/rpc/src/handlers/mining.rs. Admission stays on MiningControl::submit_block.
• Invalid hex or a payload that is not a complete block is Core -22 (Block decode failed), matching Core DecodeHexBlk. Extra bytes after a complete block are ignored.
• A second dummy argument is accepted and ignored (BIP22). A third argument is JSON-RPC -32602.

API-12: GBT proposal request parsing

• Owner: parse_block_template_request in crates/rpc/src/handlers/mining.rs.
• Unknown or non-string mode is Core -8 (Invalid mode).
• Proposal mode does not require the client to list the proposal capability. Missing data is Core -3 (Missing data String key for proposal) with no invalid type: prefix. Decode uses decode_submitted_block (API-11): -22 Block decode failed, leftover bytes ignored.

API-13: submitblock uncommitted witness nonce

• Owner: update_uncommitted_block_structures in crates/mining/src/coinbase.rs, called from MiningCoordinator::submit_block in crates/node/src/mining.rs.
• When the previous header is known, SegWit is active for the submitted height, the coinbase already has a BIP141 commitment output, and the coinbase witness is empty, submitblock inserts the 32-byte reserved nonce. This matches Core UpdateUncommittedBlockStructures.
• An existing coinbase witness is left unchanged. Proposal mode does not apply this fill.

API-14: submitblock and proposal duplicate vocabulary

• Owner: MiningCoordinator::known_block_result in crates/node/src/mining.rs.
• GBT proposal looks the block hash up first, matching Core LookupBlockIndex: a scripts-valid body is duplicate (API-21), Invalid is duplicate-invalid, and any other tree entry (including a header-only tip) is duplicate-inconclusive.
• submitblock matches Core v31 ProcessNewBlock: a scripts-valid body is duplicate. A header admitted by submitheader still receives the body.

API-15: BIP22 reject reasons

• Owner: bip22_reject_reason in crates/node/src/mining.rs.
• Proposal and submitblock project apply/consensus failures as Core GetRejectReason strings (bad-cb-missing, bad-txnmrklroot, bad-cb-amount, high-hash, time-too-old, …). Operational apply refusals (Shutdown, journal backpressure) stay inconclusive.
• Consensus crate Display remains log text. This mapping is the BIP22 wire owner.

API-16: GBT vbrequired is always 0

• Owner: MiningCoordinator::version_bits_for in crates/node/src/mining.rs.
• Core v31 getblocktemplate hardcodes vbrequired to 0. Signalling deployments still appear in vbavailable; locked-in bits are not OR'd into vbrequired.

API-17: BIP141 witness malleation reasons

• Owner: check_witness_malleation in crates/consensus/src/verify_block.rs.
• Core CheckWitnessMalleation distinguishes three BIP22 strings:
  • commitment present, coinbase witness not a single 32-byte element → bad-witness-nonce-size
  • commitment present, reserved nonce well-formed, hash mismatch → bad-witness-merkle-match
  • witness data without a commitment, or before SegWit → unexpected-witness
• Proposal does not fill an omitted reserved nonce (API-13 is submitblock-only), so an empty coinbase witness with a commitment is miner-facing bad-witness-nonce-size.
• bip22_reject_reason maps the consensus variants; consensus Display remains log text.

API-18: GBT coinbaseaux.flags is empty hex

• Owner: render_block_template in crates/rpc/src/handlers/mining.rs.
• Core v31 emits coinbaseaux: { "flags": HexStr(COINBASE_FLAGS) }. The flags bytes are empty, so the hex string is "". An empty object is not the Core shape.

API-19: prioritisetransaction dummy and fee_delta

• Owner: prioritisetransaction in crates/rpc/src/handlers/mining.rs.
• Core reads fee_delta from params[2] (getInt<int64_t>). The deprecated dummy (params[1]) must be omitted, null, or numeric zero; any other value is -8 Priority is no longer supported, dummy argument to prioritisetransaction must be 0.
• Two-argument calls do not treat params[1] as fee_delta.

API-20: prioritisetransaction refuses pooled dust

• Owner: prioritisetransaction in crates/rpc/src/handlers/mining.rs.
• Core v31 rejects a mempool transaction with dust outputs when require_standard is set: -8 Priority is not supported for transactions with dust outputs.
• require_standard follows Core's -acceptnonstdtxn default: enforced everywhere except regtest. Absent txids (fee-delta overlay only) are not checked. Dust classification uses the pool's dust-relay fee via tx_has_dust_outputs.

API-21: reorged scripts-valid bodies are duplicate

• Owner: MiningCoordinator::known_block_result in crates/node/src/mining.rs.
• Core proposal pindex->IsValid(BLOCK_VALID_SCRIPTS) is true for a body that was fully connected and later reorged. chain_tx_count != 0 is written by record_applied_tx_count after a successful apply and is not cleared on disconnect. Header-only nodes stay 0.
• Checkpoint restore writes chain_tx_count only on the applied tip. Applied-chain membership is the restore fallback so ancestors whose count is still 0 stay duplicate.
• NodeStatus::Active and Stale are header-chain displacement, including a submitheader tip, and are not the scripts-valid test.
• submitblock uses the same scripts-valid test. A stale scripts-valid resubmit is duplicate, not inconclusive-not-best-prevblk. Core BLOCK_HAVE_DATA after prune is not modeled separately.

API-22: getmininginfo omits unset optional fields

• Owner: render_mining_info in crates/rpc/src/handlers/mining.rs.
• Core pushes currentblockweight, currentblocktx, and signet_challenge only when set. Unset optionals are omitted, not JSON null. Projection uses typed_to_sonic_omitting_nulls, the same helper as GBT.

API-23: estimatesmartfee Core conf_target and estimate_mode

• Owner: estimatesmartfee in crates/rpc/src/handlers/util.rs.
• conf_target must be in 1..=1008 (Core MAX_CONFIRM_TARGET). Otherwise -8 Invalid conf_target, must be between 1 and 1008.
• estimate_mode is optional, case-insensitive UNSET / ECONOMICAL / CONSERVATIVE (Core FeeModeFromString). Unknown strings are -8 Invalid estimate_mode parameter, must be UNSET, ECONOMICAL or CONSERVATIVE. A non-string is -3. Accepted modes are parsed only; this node's estimator has one horizon.
• Trailing parameters are refused.

API-24: generateblock txid and raw-tx parse errors

• Owner: parse_generateblock_transactions in crates/rpc/src/handlers/mining.rs.
• 64-character hex is Core Txid::FromHex. A txid missing from the mempool is -5 Transaction {str} not in mempool. using the caller's string.
• Anything else is Core DecodeHexTx. Invalid hex or a payload that is not a complete transaction is -22 Transaction decode failed for {str}. Make sure the tx has at least one input.

API-25: getprioritisedtransactions modified_fee is satoshis

• Owner: getprioritisedtransactions in crates/rpc/src/handlers/mining.rs.
• Core mining RPCs use satoshi amounts, not BTC. fee_delta is already an integer satoshi overlay. modified_fee (actual fee plus delta, present only when in_mempool) is the same unit: a JSON number in satoshis, matching Core CAmount.

The wallet-facing subset of this surface — tip, fees, address/script queries, and broadcast over Esplora, plus the key-free node RPCs — is owned by wallet-facing.md.

Live gaps

• Full Core differential suite: Versioned Core response structs, golden fixtures, and differential test lanes across all RPC methods are tracked under #78 (open).
• Typed embedding surface: Direct in-process application API as an alternative to localhost JSON-RPC daemon boundary is tracked under #145 (open).

Proven by

• crates/rpc/tests/manifest_coverage.rs:
  • rpc_rows_and_the_live_registry_agree_both_ways
  • rest_rows_and_router_registrations_agree_both_ways
  • zmq_rows_are_valid_core_topics
  • every_unimplemented_rpc_row_answers_method_not_found
  • generated_reference_matches_checked_in
• crates/rpc/src/handlers/mining.rs tests generatetoaddress_projects_solved_hashes, generatetoaddress_rejects_script_hex_and_descriptors, generateblock_projects_hash_object, generateblock_accepts_addr_descriptor, generateblock_without_submit_includes_hex, generateblock_requires_transactions_array, generateblock_keeps_raw_transactions, generateblock_rejects_trailing_parameters, generateblock_rejects_invalid_supplied_checksums, generateblock_rejects_unknown_mempool_txid_like_core, generateblock_rejects_undecodable_raw_tx_like_core
• crates/node/tests/mining.rs tests generate_mines_coinbase_only_blocks_to_the_tip, generateblock_rejects_unknown_mempool_txid, generateblock_raw_tx_does_not_require_mempool_admission, generate_without_submit_does_not_advance_the_tip
• crates/mining/tests/template_shape.rs tests candidate_solves_an_unsolved_regtest_header, ordered_assembly_keeps_snapshot_order
• API-06:
  • crates/node/src/mining.rs test hash_ps_at_rejects_a_height_the_tip_cannot_resolve
  • crates/node/tests/mining.rs test network_hash_ps_rejects_core_invalid_windows
  • crates/rpc/src/handlers/mining.rs test getnetworkhashps_projects_control_invalid_request_as_invalid_parameter
• API-07:
  • crates/rpc/src/handlers/mining.rs tests getblocktemplate_forwards_longpollid, getblocktemplate_emits_submitold_and_omits_it_when_unset, getblocktemplate_requires_signet_rule_on_signet
  • crates/node/src/mining.rs test signet_template_carries_challenge_and_mandatory_rule
  • crates/node/tests/mining.rs tests template_does_not_echo_client_capabilities, signet_template_includes_challenge_and_signet_rule
• API-08:
  • crates/rpc/src/handlers/mining.rs tests getblocktemplate_rejects_mainnet_without_peers, getblocktemplate_rejects_mainnet_during_ibd, getblocktemplate_proposal_skips_mainnet_connection_gates
• API-09:
  • crates/rpc/src/handlers/mining.rs tests submitheader_rejects_undecodable_headers, submitheader_returns_null_and_forwards_decoded_header, submitheader_maps_rejected_to_verify_error
  • crates/node/tests/mining.rs tests submit_header_admits_a_mined_child_and_is_idempotent, submit_header_requires_the_previous_header, submit_header_rejects_bad_diffbits, submit_header_rejects_time_too_new
  • crates/node/src/mining.rs tests pow_failure_is_high_hash, nbits_mismatch_is_bad_diffbits
• API-10:
  • crates/rpc/src/handlers/mining.rs tests getblocktemplate_rejects_missing_segwit_rule, getblocktemplate_requires_signet_rule_on_signet, getblocktemplate_rejects_template_mandatory_rule_without_client_support, getblocktemplate_proposal_skips_client_rule_negotiation
• API-11:
  • crates/rpc/src/handlers/mining.rs tests submitblock_requires_mining_control_and_rejects_garbage_encoding, submitblock_ignores_bip22_dummy_and_trailing_bytes
• API-12:
  • crates/rpc/src/handlers/mining.rs tests getblocktemplate_rejects_invalid_mode, getblocktemplate_proposal_decode_matches_core, getblocktemplate_proposal_skips_client_rule_negotiation
• API-13:
  • crates/mining/src/coinbase.rs tests fills_reserved_nonce_when_commitment_present_and_witness_empty, leaves_an_existing_coinbase_witness_alone, skips_without_commitment_or_when_segwit_is_inactive
  • crates/node/tests/mining.rs test submit_block_fills_omitted_coinbase_witness
• API-14:
  • crates/node/tests/mining.rs tests submit_block_applies_a_header_already_in_the_tree, proposal_of_an_applied_block_is_duplicate, proposal_of_an_invalid_header_is_duplicate_invalid, proposal_of_a_header_only_block_is_duplicate_inconclusive, duplicate_submit_returns_duplicate
• API-15:
  • crates/node/src/mining.rs tests consensus_failures_use_core_bip22_reasons, header_failures_use_core_bip22_reasons
  • crates/node/tests/mining.rs tests proposal_without_coinbase_is_bad_cb_missing, proposal_merkle_mismatch_is_bad_txnmrklroot, proposal_rejects_excess_coinbase_without_side_effects
• API-16:
  • crates/node/tests/mining.rs test template_does_not_echo_client_capabilities
• API-17:
  • crates/consensus/src/verify_block.rs tests contextual_rules_reject_witness_before_segwit_activation, contextual_rules_enforce_bip141_commitment_after_segwit_activation, bip141_coinbase_witness_must_have_exactly_one_32_byte_element, bip141_witness_commitment_last_output_wins
  • crates/node/src/mining.rs test consensus_failures_use_core_bip22_reasons
  • crates/node/tests/mining.rs tests proposal_commitment_without_witness_nonce_is_bad_witness_nonce_size, proposal_witness_without_commitment_is_unexpected_witness, proposal_wrong_witness_commitment_is_bad_witness_merkle_match
• API-18:
  • crates/rpc/src/handlers/mining.rs test getblocktemplate_renders_candidate_and_reuses_control_result
  • crates/rpc/tests/core_compat.rs test mining_responses_deserialize_into_pinned_types
• API-19:
  • crates/rpc/src/handlers/mining.rs tests prioritisetransaction_calls_mempool_prioritise_directly, prioritisetransaction_rejects_nonzero_dummy_like_core, prioritisetransaction_requires_fee_delta_as_third_parameter
• API-20:
  • crates/rpc/src/handlers/mining.rs tests prioritisetransaction_rejects_dust_outputs_like_core, prioritisetransaction_allows_dust_overlay_on_regtest, prioritisetransaction_allows_absent_txid_overlay
  • crates/mempool/src/standardness.rs test dust_relay_fee_changes_the_boundary
• API-21:
  • crates/node/tests/mining.rs tests proposal_of_a_disconnected_scripts_valid_block_is_duplicate, submit_of_a_disconnected_scripts_valid_block_is_duplicate, applied_ancestor_with_unset_chain_tx_count_is_duplicate
• API-22:
  • crates/rpc/src/handlers/mining.rs tests getmininginfo_omits_unset_optional_fields, getmininginfo_can_include_signet_challenge, getmininginfo_projects_control_state
• API-23:
  • crates/rpc/src/handlers/util.rs tests estimatesmartfee_rejects_conf_target_outside_core_range, estimatesmartfee_rejects_unknown_estimate_mode, estimatesmartfee_accepts_core_estimate_modes_and_rejects_trailing
• API-24:
  • crates/rpc/src/handlers/mining.rs tests generateblock_rejects_unknown_mempool_txid_like_core, generateblock_rejects_undecodable_raw_tx_like_core, generateblock_keeps_raw_transactions
• API-25:
  • crates/rpc/src/handlers/mining.rs test getprioritisedtransactions_projects_the_overlay