Slack Web API
Public
Slack's OpenAPI 2.0 description of the Slack Web API, published by Slack under the MIT license. The repository is archived.
Use Cases
Messaging Integration
Tech / ITDevelopers post and read messages and manage conversations from their apps through Web API methods.
Agent Grounding
Tech / ITAI agents look up Slack object shapes, such as the fields of a message or a conversation, before they write code or bot logic.
Client Generation
Tech / ITDevelopers generate typed clients from the OpenAPI 2.0 file, then check newer methods by hand because the file is archived.
Overview
The Slack Web API is an interface for reading information from a Slack workspace and making changes in it. It is an HTTP RPC-style API: each method needs an OAuth token with matching scopes. Slack published an OpenAPI 2.0 description of its public methods in the slackapi/slack-api-specs repository, version 1.7.0. The repository is now archived, so the file does not cover newer methods. Slack says the specs do not always tell the whole truth. The types in this entry include objs_message, objs_channel, objs_user_profile, objs_file, objs_team, objs_reaction and objs_reminder. Developers can use this entry to check method payloads and object shapes, and should confirm details in the current Slack documentation.
Top entities
objs_message, objs_channel, objs_user_profile, objs_file, objs_team, objs_reaction, objs_reminder, objs_subteam, objs_comment, objs_bot_profile, objs_enterprise_user, objs_team_profile_field
Mappings
- schema.org Message: conceptual. objs_message aligns in intent with schema.org Message, not field by field.
For agents
Query the library's CoreModels project for Slack object shapes before writing app code. Check method details against the current Slack docs, since the source file is archived. Sample prompt: "Using the Slack Web API schema in the Schematica Library, which fields of objs_message identify its channel, author and thread?" Read via MCP: get_project_summary with graphProjectId 4513911c126b4d28873b0fbf87780f51.
Provenance
Publisher: Slack. License: MIT (https://github.com/slackapi/slack-api-specs/blob/master/LICENSE). Version: 1.7.0. Format: OpenAPI (listed here as JSON Schema until the library format list includes it). Described by the Schema Librarian on 2026-10-23; auto-cataloged.
Comments: