Proposal Anchor Contract

The proposal-anchor type script governs the lifecycle of PBLK proposal cells that are treasury-funded. It enforces that proposal cells can only be created, spent during execution, or reclaimed in ways that are consistent with the governance protocol.

What it validates

The proposal-anchor type script runs in two contexts:

At anchor creation (the anchor transaction):

• The cell data is a valid PBLK v1 or v2 payload
• The cell is locked by the registry treasury lock (lock_hash == treasury_lock_hash from the registry governance header)
• The registry_type_id_value in the cell data matches the target registry

At execute or reclaim (the governance transaction):

• The spending transaction inputs include a registry cell being updated (execute) or have the anchor aged past the reclaim delay (reclaim)
• All remaining capacity from the anchor is returned to the treasury lock
• The since field on the anchor input encodes a valid relative median-time-past delay

Error codes

Code	Name	Meaning
31	InvalidTypeArgs	Proposal-anchor type args are malformed (not 64 bytes encoding two 32-byte Type IDs)
32	InvalidTopology	Transaction input/output structure is invalid for the current operation
33	InvalidProposalData	PBLK cell data is malformed or has an unsupported version
34	UnauthorizedTreasuryLock	The cell is not locked by the registry treasury lock
35	InvalidReclaimReturn	Reclaim output does not return full capacity to the treasury lock
36	InvalidReclaimSince	The anchor input’s since field does not encode a valid relative timestamp delay

Type args layout

The proposal-anchor type args are 64 bytes:

Field	Offset	Size	Value
governance_lock_type_id	0	32 bytes	Type ID of the governance-lock contract
proposal_anchor_type_id	32	32 bytes	Type ID of this proposal-anchor contract

These values are fixed at deploy time and match the args embedded in the treasury-lock contract.

Deployed outpoint (testnet)

tx_hash: 0x0daff588f0053bdf34d4c2eebaf2c092f70192cdd4a2d1dd95aee07ce100dea9
index:   0
type_id: 0x89decc8507addb114e35c2a2e2ae943089832884818fc7ac6de3c3b8cdae6a12

Reference

• Contract source: contracts/proposal-anchor/src/main.rs
• PBLK cell layout: PBLK Proposal Cell
• Treasury model: The autonomous treasury model

See also

• The autonomous treasury model — why keyless spending works
• How to anchor a proposal — create the PBLK cell via CLI
• How to reclaim an abandoned anchor — recover treasury capacity
• PBLK Proposal Cell — the data payload inside the anchor cell
• GOV1 v4 Witness — the governance witness that references the anchor