MCP Tools

MCP Tools

Atlas MCP tools provide bounded code context to coding assistants. Start MCP over stdio for desktop agents:

atlas mcp --transport stdio

Or expose MCP through the local service:

atlas serve --mcp

Tool Selection

Tool	Use it for
code_query	Natural-language questions about a repository
search	Focused lexical or semantic discovery
symbol	Definitions, snippets, callers, callees, refs, and coverage
graph	Paths or neighborhoods between symbols
impact	Repository or cross-repository blast radius
routes	Served routes, consumers, and dependencies
context	Code-review context for changed paths
report	Repository-level code intelligence reports
history	Indexed history and graph changes
status	Index, readiness, and retrieval state
link	Register a repository for workspace or cross-repository analysis
record_feedback	Record result-quality feedback
record_task	Record the outcome of a procedural task

Recommended Starting Point

Use code_query for most repository questions. It checks index readiness and returns cited context under a bounded response budget.

Example intent:

How is checkout authorization enforced, and which tests cover it?

Use context instead when reviewing a known set of changed files:

changed_paths:
  - internal/api/handler.go
intent: review
query: correctness, regressions, and missing tests

Symbol Views

The symbol tool supports views such as:

• explain
• definition
• snippet
• callers
• callees
• neighbors
• refs
• coverage

Add package, receiver, or arity filters when a name is overloaded.

Detail and Budgets

Use:

• low for counts and minimal metadata
• medium for names and signatures
• high for repository-local evidence
• xhigh only when broader context is required

Normal budget overflow may trim results and mark them as truncated. Strict budget mode refuses an oversized answer instead.

Common Status Values

Status	Meaning
ok	Atlas returned cited context
indexing	An index was started or is still running
no_index	No usable index exists for the workspace
insufficient	The index could not support a cited answer
budget_exceeded	Strict output budget was too small
workspace_required	Repository scope was not declared

Transport Security

Stdio MCP is local to the launching assistant. HTTP MCP should stay on loopback unless authentication and origin restrictions are configured:

export ATLAS_API_TOKEN='replace-with-a-strong-token'
export ATLAS_MCP_ALLOWED_ORIGINS='https://trusted.example'
atlas serve --mcp --addr 0.0.0.0:3099

See Privacy and Data Handling before enabling networked access.