Resources

Brain's MCP server exposes 7 resource templates that let agents address Brain entities by URI. Resources complement tools: where tools are verbs (tools/call), resources are nouns (resources/read).

Property	Value
URI scheme	brain://
MCP method	resources/read
Required scope	Same as the equivalent read tool

The 7 Templates

Resource	URI Pattern	Required Scope
Ledger account	brain://ledger/accounts/{account_id}	ledger:read
Ledger transaction	brain://ledger/transactions/{transaction_id}	ledger:read
Ledger obligation	brain://ledger/obligations/{obligation_id}	ledger:read
Payment intent	brain://ledger/payment-intents/{payment_intent_id}	ledger:read
Wiki page	brain://wiki/pages/{slug}	wiki:read
PaymentIntent action types	brain://payments/action_types	payment_intent:propose
Action proof (H-07)	brain://proofs/{action_id}	audit:read

Why Resources

Tools are good for queries with arguments. Resources are good for entities with stable identifiers that an agent already knows about: a transaction id from a recent ledger.transactions.list response, a payment intent id from a previous propose, a wiki page slug like /monthly-summaries/2025-09.

Treating them as resources rather than tool calls has three benefits:

Benefit	Detail
Cacheable	An MCP runtime can cache resource reads by URI without understanding the tool's argument shape
Context-friendly	Agents can pass URIs back and forth in their planning context without re-fetching
Discoverable	resources/list enumerates the URI templates Brain advertises

Reading a Resource

POST /v1/agents/mcp HTTP/1.1
Authorization: Bearer <jwt>
Content-Type: application/json

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "resources/read",
  "params": {
    "uri": "brain://ledger/transactions/tx_4127"
  }
}

Response:

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "contents": [
      {
        "uri": "brain://ledger/transactions/tx_4127",
        "mimeType": "application/json",
        "text": "{ \"id\": \"tx_4127\", \"amount\": \"61404.12\", \"currency\": \"USD\", ... }"
      }
    ]
  }
}

URI Examples

brain://ledger/accounts/acct_8231
brain://ledger/transactions/tx_4127
brain://ledger/obligations/obl_5521
brain://ledger/payment-intents/pi_a1b2c3
brain://wiki/pages/monthly-summaries/2025-09
brain://wiki/pages/counterparties/cp_aws
brain://payments/action_types
brain://proofs/act_01HW3X9...

The Wiki URI uses the page slug, not the page id. Slugs are stable across regenerations; ids change when a page is regenerated. For agent context that needs to survive regeneration, use the slug.

Resource Discovery

resources/list

Returns the 7 static URI templates Brain advertises. It is not a per-entity enumeration: the response is the fixed template set below, not one row per account, page, or artifact.

{
  "resources": [
    {
      "uri": "brain://ledger/accounts/{account_id}",
      "name": "Account",
      "description": "Account row + latest balance.",
      "mimeType": "application/json"
    },
    {
      "uri": "brain://ledger/transactions/{transaction_id}",
      "name": "Transaction",
      "description": "Transaction row.",
      "mimeType": "application/json"
    },
    {
      "uri": "brain://ledger/obligations/{obligation_id}",
      "name": "Obligation",
      "description": "Obligation row.",
      "mimeType": "application/json"
    },
    {
      "uri": "brain://ledger/payment-intents/{id}",
      "name": "PaymentIntent",
      "description": "PaymentIntent row + PolicyDecision id.",
      "mimeType": "application/json"
    },
    {
      "uri": "brain://wiki/pages/{slug}",
      "name": "Wiki page",
      "description": "Memory page (markdown body).",
      "mimeType": "text/markdown"
    },
    {
      "uri": "brain://payments/action_types",
      "name": "PaymentIntent action types",
      "description": "Canonical action_type vocabulary + required fields for payment_intent.propose.",
      "mimeType": "application/json"
    },
    {
      "uri": "brain://proofs/{action_id}",
      "name": "Action proof (H-07)",
      "description": "Canonical proof for an executed action: gate trace, policy decision, audit before/after, Merkle proof, and on-chain anchor tx hash.",
      "mimeType": "application/json"
    }
  ]
}

Only resources/list and resources/read are implemented. There is no resources/templates/list method on the Brain MCP surface.

What Resources Are Not

Not a Resource	Why
Lists, queries, search results	Tools handle those (*.list)
Newly proposed entities	The propose tool is the canonical entry point; resources are for fetch-by-id
Streaming feeds	Single-shot HTTP today; streaming may follow when there is a clear use case

Audit

Every successful resources/read emits an agent.mcp.tool_called audit event with method: "resources/read" and the URI in inputs. This means a tenant can see exactly which agent fetched which entity at which time, just like for tool calls.

What's Next

🛠️ Tools

The 16 tools at the heart of the MCP surface.

Tools

💬 Prompts

Canned prompts for common agent loops.

Prompts