Sablier Flow Stream Cancellation

Overview

Cancel one or more Sablier Flow open-ended payment streams on the user's behalf. The skill discovers the user's streams through the Sablier indexer where the wallet is sender or recipient, drops already-voided streams, and executes one batch(bytes[]) transaction per selected stream that splices the appropriate sub-calls atomically:

• Sender (or sender + recipient) with refundable > 0 → [refundMax(streamId, sender), void(streamId)]. The sender recovers the unstreamed deposit and the stream is permanently stopped in the same transaction.
• Sender (or sender + recipient) with refundable == 0 → [void(streamId)]. Inform the user nothing is left to refund — the stream will be voided but no funds will be returned.
• Recipient-only → [void(streamId)]. Inform the user that as the recipient, they can void the stream but only the sender can refund unstreamed funds.

The skill always uses batch(bytes[]) as the entrypoint so refund + void run atomically per stream. When the batch contains a single sub-call (void only), the runbook MAY call void(uint256) directly instead of wrapping in batch — this is a small gas optimization, flagged in the runbook.

This skill charges no markup. Both void(uint256) and refund(streamId,…) are free at the protocol level — MSG_VALUE = 0 always.

This skill is a coordinator for Flow cancellation and execution routing.

Arguments

Workflow

1. Confirm product fit

1. Verify the user wants to cancel existing Sablier Flow open-ended streams.

1. If the user wants to create a Flow stream instead, route to sablier-create-open-ended-stream. If that skill is unavailable, recommend installing it with:

``bash npx skills add sablier-labs/sablier-skills --skill sablier-create-open-ended-stream ``

1. If the user wants to withdraw available tokens from a Flow stream (recipient action), route to sablier-withdraw-open-ended-stream. If that skill is unavailable, recommend installing it with:

``bash npx skills add sablier-labs/sablier-skills --skill sablier-withdraw-open-ended-stream ``

1. If the user wants to cancel a vesting stream instead of a Flow stream, route to sablier-cancel-vesting. If that skill is unavailable, recommend installing it with:

``bash npx skills add sablier-labs/sablier-skills --skill sablier-cancel-vesting ``

2. Check requested features

Stop and call out unsupported requests before selecting an execution path.

• Cross-chain batching is not supported. This skill cancels streams on a single chain per invocation. If the user has streams on multiple chains, run the skill again per chain.
• One stream per transaction. Each selected stream gets its own atomic batch(bytes[]) transaction combining the required sub-calls (refund + void, or just void). Selecting N streams produces N transactions and N wallet approvals — one per stream. This keeps each cancellation isolated: a revert on one stream never affects the others.
• Access control:

- void(streamId) — callable by the sender, the recipient, or an ERC-721-approved third party. - refund(streamId, amount) and refundMax(streamId) — sender-only. - The runbook detects each stream's caller_role (sender / recipient / both) and adjusts the batch sub-calls accordingly.

• Already-voided streams cannot be re-voided. A Flow.Status.VOIDED stream reverts on runtimeStatusOf/void. Discovery uses the indexer's voided: false filter; the runbook re-checks statusOf(streamId) per stream right before broadcast (mirrors the withdraw-flow precheck).
• Refund availability. If refundableAmountOf(streamId) == 0, only void runs — tell the user "Nothing is left to refund. The stream will be voided (stopped) but no funds will be returned." This applies to both sender callers (no unstreamed balance) and recipient callers (refund is sender-only).
• Withdrawing native tokens (ETH, POL, etc.) is not supported. Sablier Flow streams only hold ERC-20 tokens. If the user mentions "ETH from my stream", they most likely mean WETH — confirm the token symbol before proceeding.
• Tokens with more than 18 decimals are not supported by Flow. This is a contract-level invariant; no eligible stream can exceed it.

3. Clarify the required inputs

Use the AskUserQuestion tool to fill any missing inputs. Ask only for what is missing — never re-ask for values the user already provided.

• Wallet address. A 0x-prefixed EVM address — case is not enforced; the runbook lowercases it before querying the indexer. This is the address that will sign each cancel transaction. Ask for this first — both chain and token can be inferred from the indexer once the wallet is known.
• Chain name. Optional. If the user does not know which chain, do not send them to an external UI — query the Sablier Streams indexer for every non-voided Flow stream where the wallet is the sender or the recipient across all chains, collect the distinct chainId values, map them to chain names via the [Supported Chains](references/cli.md#supported-chains) table, and offer them as AskUserQuestion options. If exactly one chain has streams, auto-select it and tell the user. See [references/cli.md § Chain discovery](references/cli.md#chain-discovery).
• Token symbol. Optional. If the user does not know which token, query the indexer for every non-voided Flow stream on the resolved chain where the wallet is the sender or the recipient, and offer the distinct token symbols as AskUserQuestion options (see [references/cli.md § Stream discovery](references/cli.md#stream-discovery)).

There is no to parameter — refunds always go to the sender, that is hard-wired in the contract.

Do not guess or silently apply defaults for these parameters. Only proceed once all inputs are confirmed.

4. Validate chain support

1. Check whether the resolved chain is listed in the [Supported Chains](references/cli.md#supported-chains) table in the execution runbook.
2. If a chain surfaced by the indexer is not in the table, check Sablier Flow deployments and ask the user for an RPC URL. If still unresolved, stop execution of this skill.

5. Route to execution

Hand off to [references/cli.md](references/cli.md) for stream discovery, multi-select, preview, confirmation, and per-stream broadcast. The discovery step pipes the indexer response through [scripts/filter-cancelable.sh](scripts/filter-cancelable.sh), which Multicall3-batches statusOf(streamId) and refundableAmountOf(streamId) across every candidate into a single round trip — this drops voided streams and stamps .refundable (base-unit string) and .status onto every survivor.

Resources

• Sablier Documentation
• EVM Flow Deployments
• Sablier Indexer API
• Sablier GraphQL Schema
• Sablier Indexers Repo
• Sablier Flow Monorepo
• Sablier Flow CHANGELOG

Support

If you encounter any issues or unexpected errors with this skill, please file an issue at sablier-labs/sablier-skills.