FIP-0110: Shorter minimum deal duration (#1203)

* This FIP proposes to reduce the minimum sector / deal term from 6 to 1 month, to allow flexibility and more 'pay as you go' options.

* Apply suggestions from code review

Co-authored-by: Adrian Lanzafame <[email protected]>
Co-authored-by: Rod Vagg <[email protected]>

* claim fip-0110

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Co-authored-by: Adrian Lanzafame <[email protected]>
Co-authored-by: Rod Vagg <[email protected]>

Author: 3 people

FIPS/fip-0110.md

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+---
+fip: "0110"
+title: Allow Shorter Deal Durations
+author: "Will Scott (@willscott)"
+discussions-to: https://github.com/filecoin-project/FIPs/discussions/1205
+status: Draft
+type: Technical
+category: Core
+created: 2025-10-09
+
+---
+
+# FIP-0110: Allow Shorter Deal Durations
+
+## Simple Summary
+<!--"If you can't explain it simply, you don't understand it well enough." Provide a simplified and layman-accessible explanation of the FIP.-->
+Currently, parameters are set such that the shortest deal that is supported in Filecoin is 6 months. We have a number of use cases where clients want to pay on a monthly basis. While this is non-ideal for a storage provider because of the sealing overhead versus amount of time earned, if the expectation is that most deals will extend to periods of years, storage providers may be willing to take deals with initial 1-month durations. The protocol does not need to enforce a 6 month minimum.
+
+## Abstract
+<!--A short (~200 word) description of the technical issue being addressed.-->
+* Change the minimum market [`deal_duration_bounds`](https://github.com/filecoin-project/builtin-actors/blob/master/actors/market/src/policy.rs#L29) from 180 to 30
+* Change the runtime policy [`MIN_SECTOR_EXPIRATION`](https://github.com/filecoin-project/builtin-actors/blob/master/runtime/src/runtime/policy.rs#L352) from 180 to 30
+* Remove the redundant miner [`MIN_SECTOR_EXPIRATION`](https://github.com/filecoin-project/builtin-actors/blob/master/actors/miner/src/policy.rs#L114)
+
+## Change Motivation
+<!--The motivation is critical for FIPs that want to change the Filecoin protocol. It should clearly explain why the existing protocol specification is inadequate to address the problem that the FIP solves. FIP submissions without sufficient motivation may be rejected outright.-->
+The goal of this FIP is to allow deals / sectors to be initially stored on Filecoin for a one month time period. The functionality now exists for such data to be extended month-to-month as clients continue to pay for the data, but the initial 6 month term creates a barrier that is at odds with use cases we see as desired.
+
+## Specification
+<!--The technical specification should describe the syntax and semantics of any new feature. The specification should be detailed enough to allow competing, interoperable implementations for any of the current Filecoin implementations. -->
+The change here is to adjust the constants that define a minimum deal term. We do not change the other semantics, and also do not adjust the vesting spec - if there are direct locked funds for a miner deal they will vest over 6 months, not a 1 month period. With FVM other vesting schedules can be implemented already, so changes to the builtin actor in this regard is not seen as critical.
+
+## Design Rationale
+<!--The rationale fleshes out the specification by describing what motivated the design and why particular design decisions were made. It should describe alternate designs that were considered and related work, e.g. how the feature is supported in other languages. The rationale may also provide evidence of consensus within the community, and should discuss important objections or concerns raised during discussion.-->
+The design here aims to make the smallest possible change to enable the desired functionality. It is a change of constants, and will lead to some modification of parameters in integration tests, but should otherwise neither affect any existing / historic chain activity, or require other logic changes through builtin actors code.
+
+## Backwards Compatibility
+<!--All FIPs that introduce backwards incompatibilities must include a section describing these incompatibilities and their severity. The FIP must explain how the author proposes to deal with these incompatibilities. FIP submissions without a sufficient backwards compatibility treatise may be rejected outright.-->
+All existing sectors / deals remain at a 6 month time frame. No external systems rely on the 6 month period that we are aware of.
+
+
+## Test Cases
+<!--Test cases for an implementation are mandatory for FIPs that are affecting consensus changes. Other FIPs can choose to include links to test cases if applicable.-->
+The integation tests on policy which rely on the 180 day term will update to 30 days.
+
+## Security Considerations
+<!--All FIPs must contain a section that discusses the security implications/considerations relevant to the proposed change. Include information that might be important for security discussions, surfaces risks and can be used throughout the life cycle of the proposal. E.g. include security-relevant design decisions, concerns, important discussions, implementation-specific guidance and pitfalls, an outline of threats and risks and how they are being addressed. FIP submissions missing the "Security Considerations" section will be rejected. A FIP cannot proceed to status "Final" without a Security Considerations discussion deemed sufficient by the reviewers.-->
+No new security considerations are introduced by this change.
+
+## Incentive Considerations
+<!--All FIPs must contain a section that discusses the incentive implications/considerations relative to the proposed change. Include information that might be important for incentive discussion. A discussion on how the proposed change will incentivize reliable and useful storage is required. FIP submissions missing the "Incentive Considerations" section will be rejected. An FIP cannot proceed to status "Final" without a Incentive Considerations discussion deemed sufficient by the reviewers.-->
+The goal of this change is to allow more flexible deal durations. While this is non-ideal for a storage provider because of the sealing overhead versus amount of time earned, if the expectation is that most deals with still extend to periods of years, storage providers may be willing to take deals with initial 1-month durations. From an economic perspective, we would expect that the price for a 1-month deal would be higher per month than a 6-month deal, to account for the increased risk and overhead. While shorter deals lead to less lockup of funds, the overhead of sealing a sector is not reduced, so the overall economics for a storage provider are likely to be worse with shorter deals. However, if the expectation is that most deals will be renewed and extended, then the initial shorter deal term may be acceptable.
+
+## Product Considerations
+<!--All FIPs must contain a section that discusses the product implications/considerations relative to the proposed change. Include information that might be important for product discussion. A discussion on how the proposed change will enable better storage-related goods and services to be developed on Filecoin. FIP submissions missing the "Product Considerations" section will be rejected. An FIP cannot proceed to status "Final" without a Product Considerations discussion deemed sufficient by the reviewers.-->
+All existing sectors / deals remain at a 6 month time frame. No external systems rely on the 6 month period that we are aware of. This change enables new use cases where clients want to pay on a monthly basis, which can lead to more flexible and dynamic storage solutions on Filecoin.
+
+## Implementation
+<!--The implementations must be completed before any core FIP is given status "Final", but it need not be completed before the FIP is accepted. While there is merit to the approach of reaching consensus on the specification and rationale before writing code, the principle of "rough consensus and running code" is still useful when it comes to resolving many discussions of API details.-->
+TBD
+
+## TODO
+<!--A section that lists any unresolved issues or tasks that are part of the FIP proposal. Examples of these include performing benchmarking to know gas fees, validate claims made in the FIP once the final implementation is ready, etc. A FIP can only move to a “Last Call” status once all these items have been resolved.-->
+TODO: Implementation considerations / priorities.
+
+## Copyright
+Copyright and related rights waived via [CC0](https://creativecommons.org/publicdomain/zero/1.0/).