Incorrect arguments types for Slack node - retrieve conversation History (oldest, latest)

[BenjaminNavet]

Bug Description

in Slack node, when trying to retrieve channel history within timestamp interval (oldest and latest parameters), the error occurs :

{ "errorMessage": "Slack error response: "invalid_ts_oldest"", "errorDetails": {}, "n8nDetails": { "nodeName": "Get Channel History", "nodeType": "n8n-nodes-base.slack", "nodeVersion": 2.2, "resource": "channel", "operation": "history", "time": "17/10/2025 15:52:11", "n8nVersion": "1.111.0 (Cloud)", "binaryDataMode": "filesystem", "stackTrace": [ "NodeOperationError: Slack error response: "invalid_ts_oldest"", " at ExecuteContext.slackApiRequest (/usr/local/lib/node_modules/n8n/node_modules/.pnpm/n8n-nodes-base@file+packages+nodes-base_@aws-sdk+credential-providers@3.808.0_asn1.js@5_afd197edb2c1f848eae21a96a97fab23/node_modules/n8n-nodes-base/nodes/Slack/V2/GenericFunctions.ts:95:9)", " at processTicksAndRejections (node:internal/process/task_queues:105:5)", " at ExecuteContext.execute (/usr/local/lib/node_modules/n8n/node_modules/.pnpm/n8n-nodes-base@file+packages+nodes-base_@aws-sdk+credential-providers@3.808.0_asn1.js@5_afd197edb2c1f848eae21a96a97fab23/node_modules/n8n-nodes-base/nodes/Slack/V2/SlackV2.node.ts:554:23)", " at WorkflowExecute.executeNode (/usr/local/lib/node_modules/n8n/node_modules/.pnpm/n8n-core@file+packages+core_@opentelemetry+api@1.9.0_@opentelemetry+sdk-trace-base@1.30_08b575bec2313d5d8a4cc75358971443/node_modules/n8n-core/src/execution-engine/workflow-execute.ts:1254:8)", " at WorkflowExecute.runNode (/usr/local/lib/node_modules/n8n/node_modules/.pnpm/n8n-core@file+packages+core_@opentelemetry+api@1.9.0_@opentelemetry+sdk-trace-base@1.30_08b575bec2313d5d8a4cc75358971443/node_modules/n8n-core/src/execution-engine/workflow-execute.ts:1428:11)", " at /usr/local/lib/node_modules/n8n/node_modules/.pnpm/n8n-core@file+packages+core_@opentelemetry+api@1.9.0_@opentelemetry+sdk-trace-base@1.30_08b575bec2313d5d8a4cc75358971443/node_modules/n8n-core/src/execution-engine/workflow-execute.ts:1760:27", " at /usr/local/lib/node_modules/n8n/node_modules/.pnpm/n8n-core@file+packages+core_@opentelemetry+api@1.9.0_@opentelemetry+sdk-trace-base@1.30_08b575bec2313d5d8a4cc75358971443/node_modules/n8n-core/src/execution-engine/workflow-execute.ts:2337:11" ] } }

I figured out that passing timestamp in float type, not string correct the issue, allowing me to retrieve the correct history within time interval.

The bug is in the documentation :
https://docs.n8n.io/integrations/builtin/app-nodes/n8n-nodes-base.slack/?utm_source=n8n_app&utm_medium=node_settings_modal-credential_link&utm_campaign=n8n-nodes-base.slack#required-scopes

that leads to :
https://docs.slack.dev/reference/methods/conversations.history/

that leads to :
https://docs.slack.dev/reference/methods/conversations.history/#:~:text=latest-,string,-Optional

To Reproduce

Create slack node with config:

Resource : Channel

Operation : History

Channel : By ID {{ $json.channel_id }}

Return All : false

Limit : 100

Filters
Oldest: {{ $json.oldest_ts }}

with $json.oldest_ts = "1760104330.724000"

Expected behavior

should retrieve the channel conversation history since timestamp 1760104330.72400

Debug Info

...

Operating System

MacOs

n8n Version

1.114.3

Node.js Version

22.20.0

Database

SQLite (default)

Execution mode

main (default)

Hosting

n8n cloud

[Joffcom]

Hey @BenjaminNavet,

Thank you for reaching out! We’ve received your issue and are looking into it. To help us track this internally, we’ve created a Linear ticket with the reference: "GHC-5138".

We’ll keep you updated as we make progress, but if you have any additional details or context to share, feel free to add them here - it’s always helpful!

Thanks for your patience and for bringing this to our attention.

---

For INTERNAL use only: GHC-5138

[ShireenMissi]

Hi @BenjaminNavet,
Thanks for reporting the issue. The oldest and latest fields in the Slack node expect datetime/timestamp values. When using expressions, the value from your JSON or other sources may be a string. To ensure the node works correctly, please convert the value to the required datatype (number/float) before passing it to the node.

I’m going to close this issue, but feel free to reopen it if you encounter any other problems or open a new one. We’ll be happy to help.