> ## Documentation Index > Fetch the complete documentation index at: https://docs.prisme.ai/llms.txt > Use this file to discover all available pages before exploring further. # MCP endpoint (agentic filesystem access) > Per-knowledge-base Model Context Protocol endpoint (JSON-RPC 2.0, MCP spec 2025-06-18). Gives agents deterministic, filesystem-style access to this base's content, complementary to semantic `/search`. The `knowledge_base_id` is fixed by the URL and injected into every tool call, so an agent connected here can only read THIS base and never passes the id itself. Access control reuses the same middleware as the REST routes; content returned by the tools is redacted from execution events. Nine tools are exposed via `tools/list` and `tools/call`: `kb_search` (semantic top-k), `kb_ls` (list documents), `kb_find` (find by name), `kb_cat` (read a full document, chunks reassembled and de-duplicated), `kb_grep` (pattern search with line numbers, literal by default), `kb_head` and `kb_tail` (first and last N lines), `kb_sed` (output-only substitution, never persisted) and `kb_source_url` (resolve a citation link). Transport: POST only. A GET (SSE stream probe) returns 405; this endpoint does not offer server-streaming. ## OpenAPI ````yaml /api-reference/storage/swagger.yml post /v1/knowledge_bases/{knowledgeBaseId}/mcp openapi: 3.0.3 info: version: 1.0.0 title: Knowledges API description: > Public REST API for the Prisme.ai Knowledges (storage) workspace: knowledge bases, documents (uploaded files, web pages, remote files, connector documents), recurring web-crawl sources, semantic search, access control, per-knowledge-base API keys, and skills. Resource identifiers use the physical prefixes emitted by the implementation (`vs_` knowledge base, `vsf_` document, `seed_` web source, `kb-` API-key slug). This spec documents the public REST surface only. Internal helpers (private automations prefixed with `_`) and admin/GDPR lifecycle operations are not part of the public contract. contact: name: Prisme.ai url: https://prisme.ai servers: - url: https://{host}/v2/workspaces/slug:storage/webhooks description: Prisme.ai workspace webhooks variables: host: default: api.studio.prisme.ai description: API host (override for self-hosted or sandbox) security: - BearerAuth: [] - WorkspaceApiKeyAuth: [] tags: - name: Knowledge Bases description: >- Create, list, read, update, and delete knowledge bases (vector-backed document stores). - name: Documents description: >- Ingest and manage documents (uploaded files, web pages, remote files, connector documents) and their indexing. - name: Web Sources description: >- Recurring web crawl seeds that discover and index pages into a knowledge base. - name: Search description: Semantic search over a knowledge base. - name: MCP description: >- Per-knowledge-base Model Context Protocol endpoint for deterministic, filesystem-style access to content (kb_search, kb_ls, kb_find, kb_cat, kb_grep, kb_head, kb_tail, kb_sed, kb_source_url). - name: Access description: Per-knowledge-base access bindings (user, group, org, agent principals). - name: API Keys description: Per-knowledge-base API keys for connector authentication. - name: Stats description: Aggregate dashboard statistics. - name: Skills description: Prompt/instruction registry entries. paths: /v1/knowledge_bases/{knowledgeBaseId}/mcp: parameters: - name: knowledgeBaseId in: path required: true schema: type: string pattern: ^vs_[A-Za-z0-9-]+$ maxLength: 128 description: >- Knowledge base id. Legacy physical prefix `vs_` (the `kb_` rename is deferred). post: tags: - MCP summary: MCP endpoint (agentic filesystem access) description: > Per-knowledge-base Model Context Protocol endpoint (JSON-RPC 2.0, MCP spec 2025-06-18). Gives agents deterministic, filesystem-style access to this base's content, complementary to semantic `/search`. The `knowledge_base_id` is fixed by the URL and injected into every tool call, so an agent connected here can only read THIS base and never passes the id itself. Access control reuses the same middleware as the REST routes; content returned by the tools is redacted from execution events. Nine tools are exposed via `tools/list` and `tools/call`: `kb_search` (semantic top-k), `kb_ls` (list documents), `kb_find` (find by name), `kb_cat` (read a full document, chunks reassembled and de-duplicated), `kb_grep` (pattern search with line numbers, literal by default), `kb_head` and `kb_tail` (first and last N lines), `kb_sed` (output-only substitution, never persisted) and `kb_source_url` (resolve a citation link). Transport: POST only. A GET (SSE stream probe) returns 405; this endpoint does not offer server-streaming. operationId: knowledgeBaseMcp requestBody: required: true description: >- A single JSON-RPC 2.0 request (`initialize`, `tools/list`, or `tools/call`). content: application/json: schema: type: object required: - jsonrpc - method properties: jsonrpc: type: string enum: - '2.0' id: description: >- Request id echoed back in the response. Omit for notifications. oneOf: - type: string - type: integer method: type: string enum: - initialize - notifications/initialized - tools/list - tools/call params: type: object description: > For `tools/call`: `{ name, arguments }` where `name` is one of the nine tools and `arguments` carries that tool's parameters. The `knowledge_base_id` is injected from the path and must not be sent. examples: toolsList: summary: List the available tools value: jsonrpc: '2.0' id: 1 method: tools/list grep: summary: Grep a literal token across the base value: jsonrpc: '2.0' id: 2 method: tools/call params: name: kb_grep arguments: pattern: INV-42 responses: '200': description: > JSON-RPC 2.0 response envelope. Tool results follow the MCP `CallToolResult` shape (`content[]`, `structuredContent`, `isError`). content: application/json: schema: type: object properties: jsonrpc: type: string enum: - '2.0' id: nullable: true oneOf: - type: string - type: integer result: type: object description: >- Present on success (tool result, tools/list, or initialize). error: type: object description: >- Present on JSON-RPC errors (unknown method or tool, auth, rate limit). properties: code: type: integer message: type: string '401': $ref: '#/components/responses/Error401' '403': $ref: '#/components/responses/Error403' '404': $ref: '#/components/responses/Error404' '405': description: >- Method Not Allowed: the endpoint accepts POST only (a GET SSE stream is not offered). '429': $ref: '#/components/responses/Error429' security: - BearerAuth: [] components: responses: Error401: description: Authentication missing or invalid. content: application/json: schema: $ref: '#/components/schemas/Error' examples: unauthenticated: value: error: code: UNAUTHENTICATED message: Authentication required. Error403: description: Authentication present, authorization denied. content: application/json: schema: $ref: '#/components/schemas/Error' examples: forbidden: value: error: code: FORBIDDEN message: Caller is not allowed to access this resource. hook_rejected: summary: An external content hook blocked ingestion (sync) value: error: code: HOOK_REJECTED message: Content was rejected by a compliance hook. details: rejected_by: hook_pii_filter rejection_reason: detected_unmasked_pii Error404: description: Resource does not exist or is not visible to the caller. content: application/json: schema: $ref: '#/components/schemas/Error' examples: not_found: value: error: code: NOT_FOUND message: knowledge_base.document not found. details: resource: knowledge_base.document id: vsf_unknown Error429: description: Rate limited. headers: Retry-After: schema: type: integer description: Seconds the caller should wait before retrying. content: application/json: schema: $ref: '#/components/schemas/Error' schemas: Error: type: object description: | Single error envelope shared by every non-2xx response. `code` is the stable machine-readable identifier; `message` is the human-readable text; `details` is optional structured context. properties: error: type: object required: - code - message properties: code: type: string example: VALIDATION_ERROR message: type: string details: type: object additionalProperties: true required: - error securitySchemes: BearerAuth: type: http scheme: bearer bearerFormat: JWT description: >- User session JWT or instance API key (`iak_*`). Send as `Authorization: Bearer `. WorkspaceApiKeyAuth: type: apiKey in: header name: x-prismeai-api-key description: Workspace- or knowledge-base-scoped API key. ````