MCP Tools Reference

This document provides detailed information about each MCP tool available through the Atlantis MCP Server.

Table of Contents

• list_tools
• list_categories
• list_templates
• get_template
• get_template_chunk
• list_template_versions
• check_template_updates
• list_starters
• get_starter_info
• list_agent_assets
• get_agent_asset
• list_agent_asset_types
• search_documentation
• get_document
• get_document_chunk
• validate_naming

list_tools

Retrieve the complete catalog of MCP tools supported by this server, including each tool’s name, description, and input schema. Use this as the first call in a session to discover available capabilities. Returns an empty array if no tools are configured on the server.

Input Parameters

None.

Example Usage

Ask your AI: "What tools does the Atlantis MCP server provide?"

Use Cases

• Discover all available tools at the start of a session
• Review tool input schemas for parameter details

list_categories

List all available template categories with their descriptions and template counts. Takes no parameters. Returns an empty array if no categories are configured. Use this to discover which categories are available before calling list_templates or get_template.

Input Parameters

None.

Example Usage

Ask your AI: "What template categories are available?"

Use Cases

• Discover how templates are organized
• Understand available infrastructure types before browsing templates

list_templates

List all CloudFormation templates available for deployment via Atlantis scripts, filtered by category, version, or S3 bucket. Categories include: storage, network, pipeline, service-role, and modules. Returns template metadata such as name, version, category, description, namespace, and S3 location. Returns an empty array if no templates match the specified filters. Use the category parameter to narrow results when you know the resource type you need.

Input Parameters

Note: 63klabs is the only bucket and atlantis is the only namespace available via the public Atlantis MCP server. If your organization hosts its own Atlantis MCP server there may be additional namespaces and S3 buckets available.

Example Usage

List all templates:

Ask your AI: "Show me all available CloudFormation templates"

Filter by category:

Ask your AI: "Show me storage templates"

Filter by version:

Ask your AI: "Show me templates version v2.0.18"

Use Cases

• Discover available templates for your infrastructure needs
• Browse templates by category (pipeline, storage, network, etc.)
• Find specific template versions

get_template

Retrieve a specific CloudFormation template with its full content, parameters, outputs, version information, and S3 location. Requires both templateName and category parameters. Returns an error if either required parameter is missing or if the template is not found in the specified category. Optionally pass version or versionId to fetch a specific version rather than the latest.

If the template is too large to return in a single response, a summary is returned instead with contentTruncated: true and totalChunks indicating how many chunks the content was split into. Use get_template_chunk to retrieve the full content incrementally.

Input Parameters

Note: If both version and versionId are provided, they are treated as an OR condition (returns template matching either).

Note: 63klabs is the only bucket and atlantis is the only namespace available via the public Atlantis MCP server. If your organization hosts its own Atlantis MCP server there may be additional namespaces and S3 buckets available.

Example Usage

Get latest version:

Ask your AI: "Get the pipeline template"

Get specific version:

Ask your AI: "Get template-pipeline.yml version v2.0.18"

Use Cases

• Review template content before deployment
• Compare template versions
• Extract parameter definitions
• Understand template outputs

get_template_chunk

Retrieve a specific chunk of a large CloudFormation template that was too large to return in a single get_template response. Requires templateName, category, and chunkIndex (zero-based integer) parameters. Returns an error if any required parameter is missing, if the template is not found, or if chunkIndex is out of range. The response includes chunkIndex, totalChunks, templateName, category, and the chunk content as a text string. Optionally pass version, versionId, s3Buckets, or namespace to target a specific template version. Use this tool after receiving a truncated get_template response to retrieve the full content incrementally.

Input Parameters

Example Usage

Ask your AI: "The pipeline template was truncated. Get chunk 0 of template-pipeline.yml from the pipeline category"

Use Cases

• Retrieve full content of large templates that exceeded the single-response size limit
• Incrementally fetch template content chunk by chunk

list_template_versions

List all available versions of a specific CloudFormation template, returning version history with Human_Readable_Version, S3_VersionId, last modified date, and size. Requires both templateName and category parameters. Returns an error if either required parameter is missing or if the template does not exist. Use this to compare versions before upgrading or to find a specific historical version.

Input Parameters

Note: 63klabs is the only bucket and atlantis is the only namespace available via the public Atlantis MCP server. If your organization hosts its own Atlantis MCP server there may be additional namespaces and S3 buckets available.

Example Usage

Ask your AI: "Show me all versions of the pipeline template"

Use Cases

• Track template evolution over time
• Find specific versions for rollback
• Compare version metadata
• Audit template changes

check_template_updates

Check whether newer versions are available for a CloudFormation template and return update information including version, release date, changelog, and migration guide links for breaking changes. Requires templateName, category, and currentVersion parameters. Returns an error if any required parameter is missing or if the template is not found. Pass the currentVersion as a Human_Readable_Version string (e.g., v1.2.3/2024-01-15), Short_Version (e.g., v1.2.3), or S3_VersionId to compare against the latest available version.

Input Parameters

Note: 63klabs is the only bucket and atlantis is the only namespace available via the public Atlantis MCP server. If your organization hosts its own Atlantis MCP server there may be additional namespaces and S3 buckets available.

Example Usage

Check single template:

Ask your AI: "Check if template-pipeline.yml v2.0.17 has updates"

Check multiple templates:

Ask your AI: "Check for updates on all my templates"

Use Cases

• Stay current with template improvements
• Plan template upgrades
• Identify breaking changes before upgrading
• Review changelogs and migration guides

list_starters

List all available application starter code repositories with metadata including name, description, languages, frameworks, features, and S3 location. Starters provide CloudFormation templates, build specs, and Lambda function code for bootstrapping new projects. Returns an empty array if no starters match the specified filters. Optionally filter by s3Buckets or namespace.

Input Parameters

Note: 63klabs is the only bucket and atlantis is the only namespace available via the public Atlantis MCP server. If your organization hosts its own Atlantis MCP server there may be additional namespaces and S3 buckets available.

Example Usage

List all starters:

Ask your AI: "Show me available application starters"

Use Cases

• Find starter code for new projects
• Discover pre-configured application templates
• Identify starters with specific integrations
• Bootstrap new serverless applications

get_starter_info

Retrieve detailed information about a specific starter code repository, including languages, frameworks, features, prerequisites, and S3 location. Requires the starterName parameter. Returns an error if starterName is missing or if no starter matches the given name. Use this after list_starters to get full details on a specific starter before initializing a project.

Input Parameters

Note: 63klabs is the only bucket and atlantis is the only namespace available via the public Atlantis MCP server. If your organization hosts its own Atlantis MCP server there may be additional namespaces and S3 buckets available.

Example Usage

Ask your AI: "Tell me about the atlantis-starter-02 repository"

Use Cases

• Understand starter capabilities before using
• Review prerequisites and setup requirements
• Access example code snippets
• Check latest release information

list_agent_assets

List available Kiro agent assets — reusable example steering documents, hooks, and AGENTS.md files (and other AI-assistant enhancement examples) — optionally filtered by asset type, S3 bucket, or namespace. Supported assetType values are the currently enabled types: steering, hooks, and agents-md. The registry also defines a skills type, but it is disabled by default and is not a valid assetType value until an administrator enables it — use list_agent_asset_types to discover the enabled values dynamically rather than hardcoding them. When assetType is omitted, results span every enabled type. Returns metadata for each matching asset (name, type, namespace, bucket, s3Path, size, etag, lastModified) but not content — use get_agent_asset to retrieve an asset’s full content. Returns an empty array, not an error, when no assets match the specified filters.

Input Parameters

Note: 63klabs is the only bucket and atlantis is the only namespace available via the public Atlantis MCP server. If your organization hosts its own Atlantis MCP server there may be additional namespaces and S3 buckets available.

Example Usage

List all agent assets:

Ask your AI: "Show me available Kiro steering documents"

Filter by type:

Ask your AI: "List all Kiro hooks available from Atlantis"

Use Cases

• Discover reusable steering documents before starting a new project
• Browse available hooks by type before deciding which to pull in
• Check an AGENTS.md file’s size/etag/lastModified without downloading its content

get_agent_asset

Retrieve one Kiro agent asset’s full content by assetType and name. Both parameters are required; supported assetType values are the currently enabled types: steering, hooks, and agents-md. name is the exact filename (e.g. product-guidelines.md) with no path separators. Returns the asset’s content together with name, type, namespace, bucket, s3Path, size, etag, sha256, and lastModified. Returns an ASSET_NOT_FOUND error listing the available asset names for that type when name does not exist for the requested assetType.

Input Parameters

Note: 63klabs is the only bucket and atlantis is the only namespace available via the public Atlantis MCP server. If your organization hosts its own Atlantis MCP server there may be additional namespaces and S3 buckets available.

Tip — keeping a local copy in sync: If you maintain a local copy of a steering document, hook, or AGENTS.md file, compare its cached size and etag (from a prior list_agent_assets or get_agent_asset call) against the latest response before overwriting it. For a stronger check, compute the SHA-256 of your local file’s bytes and compare it to the returned sha256 — a match means your local copy is already current and no re-fetch or overwrite is needed.

Example Usage

Ask your AI: "Get the product-guidelines.md steering document"

Use Cases

• Pull a steering document into a new repository
• Retrieve a hook definition to install locally
• Check whether a local copy of an AGENTS.md file is out of date using sha256 comparison

list_agent_asset_types

List every enabled Kiro agent asset type together with a count of the assets discoverable for that type across the configured S3 buckets and indexed namespaces. Takes no parameters. Returns an empty list if no asset types are enabled. Use the returned name values as the assetType argument to list_agent_assets and get_agent_asset.

Input Parameters

None.

Example Usage

Ask your AI: "What types of agent assets are available?"

Use Cases

• Discover which asset types are enabled before calling list_agent_assets
• See how many assets exist per type before deciding what to browse
• Confirm a type like skills is not yet enabled on this server

search_documentation

Search Atlantis documentation, tutorials, and code patterns by keyword. Returns results with title, excerpt, file path, GitHub URL, and result type. Requires the query parameter. Returns an empty array if no documents match the query. All filters are optional: type and subType narrow the result set, and ghusers narrows to specific GitHub organizations.

Tip: On servers where it is enabled, eligible (paid/private) tiers receive results ranked by meaning rather than exact keywords — using the same tool and the same response shape. See Semantic Documentation Search.

Input Parameters

Response Fields

Each result includes title, excerpt, filePath, githubUrl, type, subType, relevanceScore, repository, repositoryType, and namespace. githubUrl, repositoryType, and namespace may be null for entries indexed before those fields were populated.

The envelope also includes:

• availableFilters (optional) — the distinct type and subType values present in the matched set, with counts, e.g. { "type": [{ "value": "documentation", "count": 22 }], "subType": [...] }. Use these values directly as type/subType filters on a follow-up query. Absent when there is nothing to report (e.g. zero results).
• suggestions — used for zero-result guidance as before, and also gains a “narrow the search with a type or subType filter” hint when the matched set is large, pointing you at availableFilters.

Example Usage

General search:

Ask your AI: "Search documentation for DynamoDB caching"

Filter by type:

Ask your AI: "Find code examples for Lambda functions"

Narrow a broad result set:

Ask your AI: "That search had too many results — narrow it to type template-pattern"

Use Cases

• Find implementation guidance
• Discover code patterns and examples
• Locate troubleshooting information
• Learn best practices
• Find CloudFormation resource patterns
• Narrow a broad result set using the availableFilters values from a prior search

get_document

Retrieve the complete source file behind a search_documentation result, rather than the excerpt. Supply exactly one lookup key: the filePath (contentPath) from a search result, or a section hash (16 hexadecimal characters). A section-level key resolves to the file that contains it, so the response is the whole source file in document order, not just the matched section.

Retrieval is storage-only — the server never fetches from GitHub. If the document is not currently in the index, the tool returns an error that identifies what you asked for and includes the file-level githubUrl (when it can be derived) so you can fetch the file yourself. get_document requires no elevated tier and works the same whether or not semantic search is enabled.

Input Parameters

Supply exactly one of filePath or hash — providing both, or neither, is rejected.

Response Fields

If the document exceeds the response size limit, a summary is returned instead with contentTruncated: true, totalChunks, and a retrievalHint describing how to use get_document_chunk.

Storage-miss behavior

When the document isn’t in storage, get_document returns a DOCUMENT_NOT_FOUND error carrying the requested filePath/hash and the file-level githubUrl (or null when no URL could be derived). The server does not attempt to fetch the file from GitHub on your behalf — use the returned githubUrl to fetch it directly.

Example Usage

Ask your AI: "Get the full source file for that last search result"

Use Cases

• Read the full context around an excerpt that looked relevant
• Retrieve a document by the filePath or hash returned from search_documentation
• Fall back to fetching from GitHub yourself when a document isn’t indexed yet

get_document_chunk

Retrieve a specific chunk of a large document that was too large to return in a single get_document response. Takes the same lookup key as get_document (exactly one of filePath or hash) plus a required zero-based chunkIndex.

Input Parameters

Response Fields

The response includes chunkIndex, totalChunks, filePath, and the chunk content as a text string.

Returns an INVALID_CHUNK_INDEX error if chunkIndex is out of range, or a DOCUMENT_NOT_FOUND error (same shape as get_document) if the document is no longer in storage.

Example Usage

Ask your AI: "That document was truncated. Get chunk 0"

Use Cases

• Retrieve the full content of a large document that exceeded the single-response size limit
• Incrementally fetch document content chunk by chunk, concatenating chunks 0 through totalChunks - 1 to reassemble the full document

validate_naming

Validate a resource name against Atlantis naming conventions and return parsed components with any validation errors. Supports S3 bucket patterns (regional with -an suffix, global with AccountId-Region, and simple global), as well as application, DynamoDB, Lambda, CloudFormation, and service-role resource types. The service-role type validates names against the pattern PREFIX-ProjectId-ResourceSuffix where PREFIX must be ALL CAPS (uppercase letters and digits only) and no StageId is present. Unrecognized resource types are validated using the standard application resource pattern (Prefix-ProjectId-StageId-ResourceSuffix). Requires the resourceName parameter. Returns a validation error if the name does not conform to any recognized pattern. When resource names contain hyphenated components, supply known values such as prefix, projectId, or stageId for accurate parsing. Set isShared to true for shared resources that omit StageId, and hasOrgPrefix to true when the S3 bucket includes an organization prefix segment.

Input Parameters

Example Usage

Validate application resource:

Ask your AI: "Validate this name: acme-person-api-test-GetPersonFunction"

Validate S3 bucket:

Ask your AI: "Is this S3 bucket name valid: acme-myapp-test-123456789012-us-east-1-an"

Validate with known components:

Ask your AI: "Validate acme-my-app-test-Users with prefix acme and projectId my-app"

Use Cases

• Verify resource names before deployment
• Ensure naming convention compliance
• Parse resource names into their components
• Validate S3 bucket names across all three patterns
• Check service-role naming with ALL CAPS prefix

Error Responses

All tools return errors in a consistent format:

{
  "error": {
    "code": "TEMPLATE_NOT_FOUND",
    "message": "Template 'invalid-template.yml' not found",
    "details": {
      "availableTemplates": ["template-pipeline.yml", "template-storage.yml"]
    },
    "requestId": "abc-123-def-456"
  }
}

Common error codes: - INVALID_INPUT - Input validation failed - TEMPLATE_NOT_FOUND - Requested template doesn’t exist - STARTER_NOT_FOUND - Requested starter doesn’t exist - ASSET_NOT_FOUND - Requested agent asset doesn’t exist - DOCUMENT_NOT_FOUND - Requested document isn’t in storage; the error includes githubUrl (or null) so the client can fetch it directly - INVALID_CHUNK_INDEX - chunkIndex passed to get_document_chunk (or get_template_chunk/get_agent_asset_chunk) is out of range - RATE_LIMIT_EXCEEDED - Too many requests (HTTP 429) - INTERNAL_ERROR - Server error (HTTP 500)

Rate Limiting

All tools are subject to rate limiting. Limits vary by tier — see the rate limits page for the full breakdown.

• Rate limit headers included in all responses
• HTTP 429 returned when exceeded

Related Documentation

• Semantic Documentation Search - Meaning-ranked search_documentation results for eligible tiers
• Integration Guides - Set up your AI assistant
• Common Use Cases - Practical examples
• Troubleshooting - Common issues and solutions

Support

If you need help with a specific use case:

• Documentation: Full Docs on GitHub
• GitHub Issues: Report Issue