Configuration files

Tile configuration

tile.json

The tile.json file is the configuration file for a tile. It includes important metadata that helps Tessl identify, version and describe tiles.

Tiles can contain three types of content:

• docs: Documentation files (markdown) that provide technical documentation, usage guides, API references, etc.

• rules: Rule files (markdown) that provide subjective guidance and instructions to agents, such as coding standards, best practices, and organizational policies.

• skills: Skill files (SKILL.md format) that extend AI coding agents with specialized knowledge, workflows, or tool integrations. Skills follow the Agent Skills Specification.

A tile can contain one or more of these content types. For example, a tile might have only documentation, only rules, only skills, or any combination of the three.

Here's an example tile.json:

{
  "name": "tessl/npm-shadcn",
  "version": "3.6.0",
  "docs": "docs/index.md",
  "describes": "pkg:npm/[email protected]",
  "summary": "CLI and programmatic API for adding UI components from registries. Supports multi-registry, dependency resolution, code transformation, and MCP integration for AI assistants.",
  "private": false
}

The following sections show examples of tiles with different content types. Remember that tiles can contain docs, rules, skills, or any combination of these three content types.

For example, here's what the tile.json for a private, rules-only tile might look like:

  {
    "name": "myorg/code-style",
    "version": "0.0.1",
    "summary": "TypeScript code style guidelines for MyOrg",
    "private": true,
    "steering": {
      "naming": {
        "rules": "rules/naming.md"
      },
      "exceptions": {
        "rules": "rules/exceptions.md"
      }
    }
  }

And here's a tile that includes rules as a complement:

  {
    "name": "myorg/queue-connector",
    "version": "1.2.0",
    "summary": "Message queue SDK and its best practices for MyOrg",
    "docs": "docs/index.md",
    "steering": {
      "dead-letter-handling": {
        "rules": "rules/dead-letter-handling.md"
      },
      "dev-mode": {
        "rules": "rules/dev-mode.md"
      }
    }
  }

Tiles can also contain skills, which are reusable capabilities that extend AI coding agents. Here's an example of a tile with skills:

  {
    "name": "myworkspace/my-skill",
    "version": "1.0.0",
    "summary": "A skill that provides specialized functionality for my agent",
    "private": true,
    "skills": {
      "my-skill": {
        "path": "skills/my-skill/SKILL.md"
      }
    }
  }

And here's a tile that combines documentation, rules, and skills:

  {
    "name": "myorg/comprehensive-tile",
    "version": "2.0.0",
    "summary": "Complete tile with docs, rules, and skills",
    "docs": "docs/index.md",
    "steering": {
      "code-style": {
        "rules": "rules/code-style.md"
      }
    },
    "skills": {
      "database-helper": {
        "path": "skills/database-helper/SKILL.md"
      }
    }
  }

tile.json supports a number of straightforwardly-named fields:

name (string, required): Name for the tile in workspace/tile-name format

version (string, required): Semantic version of the tile

summary (string, required): Brief description of the tile

private (boolean, optional): Controls tile visibility in the registry. Set to false to make the tile publicly discoverable by all users, or true to restrict access to your workspace only. Defaults to true if not specified. Note: Authentication with tessl login is required to publish tiles regardless of this setting.

docs (string, optional*): Path to tile documentation entrypoint (e.g. "docs/index.md")

describes (string, optional*): Package URL of the external package this tile documents.

steering (object, optional*): An object mapping rule names to their markdown files. Used to provide subjective guidance and instructions to agents, rather than technical documentation.

skills (object, optional*): An object mapping skill names to their SKILL.md file paths. Skills are reusable capabilities that extend AI coding agents with specialized knowledge, workflows, or tool integrations. Each skill entry should have a path field pointing to the SKILL.md file. Skills must follow the Agent Skills Specification.

*A note on tile.json validation:

1. If describes is set, docs is required

2. Either docs, steering, or skills must be present in tile.json. As demonstrated above, you can also include multiple content types.

Project configuration

tessl.json

The tessl.json file is the manifest for your project's tile dependencies. It specifies which tiles are installed and their versions:

{
  "name": "my-project",
  "dependencies": {
    "workspace/tile-name": {
      "version": "1.0.0"
    }
  }
}

This file is created automatically when you run tessl init or tessl install. Tessl manages the dependencies in this file as you install or uninstall tiles.

Project Mode (Managed vs Vendored)

The mode field in tessl.json controls how tile content is managed in your project. You can choose between two modes depending on your workflow and requirements:

Managed mode

Default for existing projects - Tile contents are gitignored like node_modules

{
  "name": "my-project",
  "mode": "managed",
  "dependencies": {
    "workspace/tile-name": {
      "version": "1.0.0"
    }
  }
}

Behavior:

• Tile contents in .tessl/tiles/ are automatically added to .gitignore

• Tiles are reinstalled from the registry based on tessl.json

• Works like package managers (npm, pip) - dependencies not committed

• Keeps repository clean and small

• Team members run tessl install after cloning the repository

Best for:

• Projects with frequent tile updates

• Teams who prefer lighter repositories

• Standard development workflows with internet access

Vendored mode

Default for new projects - Tile contents are committed to your repository

{
  "name": "my-project",
  "mode": "vendored",
  "dependencies": {
    "workspace/tile-name": {
      "version": "1.0.0"
    }
  }
}

Behavior:

• Tile contents in .tessl/tiles/ are committed to version control

• Exact tile versions are checked into the repository

• Works offline without registry access

• Team members get tiles automatically when cloning

• Ensures reproducible builds in all environments

Best for:

• Air-gapped or restricted network environments

• Projects requiring complete offline capability

• Ensuring exact reproducibility without external dependencies

• Compliance requirements for vendoring all dependencies

Switching modes

You can change modes at any time by updating the mode field in tessl.json:

{
  "name": "my-project",
  "mode": "vendored",  // Change to "managed" or "vendored"
  "dependencies": {
    "workspace/tile-name": {
      "version": "1.0.0"
    }
  }
}

After changing the mode:

• Tessl will automatically update .gitignore accordingly

• In managed mode, .tessl/tiles/ will be added to .gitignore

• In vendored mode, .tessl/tiles/ will be removed from .gitignore

• Commit the changes to apply the new mode for your team

Default behavior

• New projects (running tessl init in a fresh project): Defaults to vendored mode

• Existing projects (running tessl init in a project with existing tiles): Defaults to managed mode

• You can explicitly set the mode in tessl.json to override the default

.tessl directory

The .tessl directory contains Tessl's configuration and cached data:

.tessl/
|-- .gitignore                  # Ignores tiles/ and RULES.md (in managed mode)
|-- tiles/                      # Downloaded tiles
|   `-- workspace/
|       `-- tile-name/
|           |-- tile.json
|           |-- docs/            # Documentation files
|           |-- rules/           # Rule files
|           `-- skills/          # Skill files
|               `-- skill-name/
|                   `-- SKILL.md
`-- RULES.md                    # Generated rules for agents (not committed to git)

The .tessl/.gitignore file is automatically managed based on your project mode:

• Managed mode: The tiles/ directory and RULES.md are added to .gitignore (not committed to version control)

• Vendored mode: The tiles/ directory is removed from .gitignore (committed to version control), but RULES.md remains ignored as it's generated from tile content

Agent rule files

Tessl creates and updates rule files for AI coding agents to help them understand your project context and installed tiles. The location and format of these files varies by agent:

• Cursor:

  • .cursor/rules/tessl__*.mdc - Tile-specific rules (auto-generated, not committed to git)

  • .cursor/rules/tessl_context.mdc - Instructions for gathering context from Tessl MCP

• Claude Code:

  • CLAUDE.md - Context file with instructions for gathering context from Tessl MCP

  • .tessl/RULES.md - Consolidated rules from all installed tiles

  • AGENTS.md - If this file exists, Tessl adds a reference to .tessl/RULES.md

These files are created when you run tessl init --agent <agent-name> or when Tessl auto-detects an agent in your project.

MCP configuration files

When configuring AI agents, Tessl adds MCP (Model Context Protocol) server configuration to connect the agent to Tessl's MCP server. The location varies by agent:

• Cursor: .cursor/mcp.json

• Claude Code: .mcp.json in the project root

These files configure the agent to run tessl mcp start as an MCP server, enabling the agent to access Tessl's tools and context.

AGENTS.md

The AGENTS.md file provides project context to AI coding agents. This file is similar to CLAUDE.md and other agent context files used by various AI coding assistants.

Note: Tessl does not create or manage AGENTS.md directly. However, if AGENTS.md exists in your project, Tessl will automatically add a reference to .tessl/RULES.md when you configure an agent with tessl init. This allows your agent to access tile-specific guidance and context.

If you're using AGENTS.md in your project:

• Add your own project context, coding conventions, and patterns

• Tessl will append a section linking to .tessl/RULES.md (marked with <!-- tessl-managed -->)

• The content is used by AI agents during code generation

.tileignore

Exclude files from tile validation and packing.

Purpose

The .tileignore file allows you to exclude files from orphaned file warnings and prevent them from being included in published tile packages.

Location

Place a .tileignore file in the root of your tile directory (same level as tile.json).

Syntax

Uses gitignore-style patterns:

# Comments start with #

# Exact file names
notes.md

# Glob patterns
*.draft.md

# Directory patterns (trailing slash)
drafts/

# Recursive patterns
**/internal/**

# Path-specific patterns
docs/internal.md

# Negation patterns (exclude from ignore)
!important.md

Default ignored files

These files are always ignored, even without a .tileignore file:

• AGENTS.md

• CLAUDE.md

• GEMINI.md

Important rules

• Links to ignored files cause errors: If your docs link to a file that's in .tileignore, validation will fail. This prevents broken links in published tiles.

• Manifest files can't be ignored: You cannot put docs, rules, or skills entrypoints in .tileignore.

Example .tileignore

# Development notes
notes.md
TODO.md

# Draft files
*.draft.md

# Local testing
test-data/

# Keep this one even though it matches *.draft.md
!important.draft.md

User preferences

Tessl stores user preferences globally to customize your experience. You can view and modify these preferences using the tessl config commands.

Available preferences

• shareUsageData - Whether to share telemetry and usage data with Tessl (defaults to true)

• agents - Which agents to configure on tessl init (default to auto-detect when empty); see supported agents in tessl init --help .

Managing preferences

View all current preferences:

tessl config get

View a specific preference:

tessl config get shareUsageData

Set a preference:

tessl config set shareUsageData false

Opting out of telemetry

To opt out of sharing telemetry and usage data:

tessl config set shareUsageData false

For more information about data collection, see Sharing Usage Data.