# save_profile_layer [SUPPORT] 0bec79a7 (PROFILE-5) — Validate and persist ONE layer of the hosted_default -> workspace -> user -> project -> session profile contract (see meridian.profile_contract.FIELD_REGISTRY for the full field list and per-field allowed_layers/merge_strategy/narrow_only rules). REPLACES this scope's stored fields/reset_fields wholesale (not a merge) — to add one field to an existing layer, pass the full desired field set, not a delta. Rejects deterministically with {error} on an unknown field, a field not allowed at this scope_type, a secret-shaped value, a machine-local absolute path (outside the field's path_allowed_from_layer), an unsafe/destructive shell command (executor_config.test_cmd/deploy_cmd), or a malformed capability_manifest_ref. expected_revision enables optimistic concurrency: omit it for last-write-wins, or pass the revision you last read from get_profile_layer to fail with a structured {error, code: 'STALE_REVISION', current_revision} instead of silently clobbering a concurrent write. override_reason is accepted for forward symmetry with the narrow_only-widen override knob used at resolve time (get_effective_profile) but this tool itself never blocks a write on it — narrow_only/safe_direction enforcement happens at MERGE time, not write time, since a layer may legitimately declare any value for a field it owns. An idempotent no-op resave (identical fields/reset_fields) returns the current row unchanged with no revision bump. Persistent-state disclosure: on hosted Meridian, supplied text and project/session metadata are sent to and stored in Meridian's service; self-hosted deployments keep them in the configured local SQLite/Postgres database. This data is visible in the dashboard/API and later project context or handoffs. Delete individual tasks, notes, or decisions where supported, or delete the project/account using the documented controls. Do not include secrets. Agent View of the PolicyLayer registry record for `save_profile_layer`. HTML page: https://policylayer.com/tools/io-github-ajc3xc-meridian/save-profile-layer ## Facts - Tool: `save_profile_layer` - Server: Meridian (`@meridianmcp/mcp`) — https://policylayer.com/tools/io-github-ajc3xc-meridian.md - Install: `npx -y @meridianmcp/mcp` - Homepage: https://github.com/meridianmcp/Meridian - Risk category: Write (Medium risk) - Registry record: grade F, identity unverified - Server auth posture: open - Server CORS policy: * - Server rate-limited: no - Parameters: 8 (2 required) - Recommended policy verdict: Rate-limited ## Parameters | Parameter | Type | Required | Description | | --- | --- | --- | --- | | `actor` | string | no | Optional human/session identity recorded on the hosted_default audit ledger (ignored for non-hosted_default scopes, which are not ledgered). | | `fields` | object | no | This layer's field declarations — replaces whatever is currently stored at this scope. See meridian.profile_contract.FIELD_REGISTRY for the valid field names. | | `scope_id` | string | yes | | | `provenance` | object | no | Non-secret provenance for this layer's declaration (config source, hashes, observed_at, client/server identity). No secrets or machine-local absolute paths. | | `scope_type` | string | yes | | | `reset_fields` | array | no | Field names this layer explicitly resets back to inheriting from a less-specific layer. Replaces this scope's previous reset_fields list. | | `override_reason` | string | no | Accepted for symmetry with resolve-time override_reason; this tool does not itself gate on it. | | `expected_revision` | integer | no | Optimistic-concurrency guard — must match the scope's current revision or the write is rejected with STALE_REVISION. Omit for last-write-wins. | Parameters from the server's own tool schema. ## Example call (MCP tools/call, JSON-RPC 2.0) ```json { "jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": { "name": "save_profile_layer", "arguments": { "scope_id": "", "scope_type": "" } } } ``` ## Why save_profile_layer is rated Medium An AI agent can call save_profile_layer faster than any human can review: one bad instruction and it creates or modifies resources in Meridian by the hundred, each call as confident as the last. ## Use case AI agents use save_profile_layer to create or update resources in Meridian, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Meridian environment. ## Recommended policy (PolicyLayer) Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Meridian: ```json { "version": "1", "default": "deny", "tools": { "save_profile_layer": { "limits": [ { "counter": "save_profile_layer_rate", "window": "minute", "max": 30, "scope": "grant" } ] } } } ``` ## Other tools on Meridian (174) - `archive_decision` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/archive-decision.md - `batch_mutate` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/batch-mutate.md - `claim_sprint_item` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/claim-sprint-item.md - `clear_capability_profile` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/clear-capability-profile.md - `clone_profile_layer` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/clone-profile-layer.md - `delete_custom_hook` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/delete-custom-hook.md - `delete_note` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/delete-note.md - `delete_sprint_item_pointer` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/delete-sprint-item-pointer.md - `fan_out_sprint_items` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/fan-out-sprint-items.md - `purge_ai_log` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/purge-ai-log.md - `record_handoff_correction` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/record-handoff-correction.md - `release_docx_region_claims` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/release-docx-region-claims.md - `request_hitl` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/request-hitl.md - `reset_plugin_override` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/reset-plugin-override.md - `reset_profile_layer` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/reset-profile-layer.md - `complete_wave_gate` — Execute — https://policylayer.com/tools/io-github-ajc3xc-meridian/complete-wave-gate.md - `execute_batch` — Execute — https://policylayer.com/tools/io-github-ajc3xc-meridian/execute-batch.md - `prospect_symbol` — Execute — https://policylayer.com/tools/io-github-ajc3xc-meridian/prospect-symbol.md - `run_verification` — Execute — https://policylayer.com/tools/io-github-ajc3xc-meridian/run-verification.md - `start_session` — Execute — https://policylayer.com/tools/io-github-ajc3xc-meridian/start-session.md - `analyze_model_efficiency` — Read — https://policylayer.com/tools/io-github-ajc3xc-meridian/analyze-model-efficiency.md - `analyze_sprint` — Read — https://policylayer.com/tools/io-github-ajc3xc-meridian/analyze-sprint.md - `batch_read` — Read — https://policylayer.com/tools/io-github-ajc3xc-meridian/batch-read.md - `find_outputs_by_source` — Read — https://policylayer.com/tools/io-github-ajc3xc-meridian/find-outputs-by-source.md - `find_similar_equation` — Read — https://policylayer.com/tools/io-github-ajc3xc-meridian/find-similar-equation.md - `find_similar_figure` — Read — https://policylayer.com/tools/io-github-ajc3xc-meridian/find-similar-figure.md - `find_similar_table` — Read — https://policylayer.com/tools/io-github-ajc3xc-meridian/find-similar-table.md - `find_symbol_usages` — Read — https://policylayer.com/tools/io-github-ajc3xc-meridian/find-symbol-usages.md - `get_agent_instructions` — Read — https://policylayer.com/tools/io-github-ajc3xc-meridian/get-agent-instructions.md - `get_blog_posts` — Read — https://policylayer.com/tools/io-github-ajc3xc-meridian/get-blog-posts.md - …and 144 more: https://policylayer.com/tools/io-github-ajc3xc-meridian.md ## For agents This record is a snapshot. Live verdicts and the full registry: - Check every server in your MCP config at once: `npx -y policylayer stack` - Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md) - Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events` --- Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=io-github-ajc3xc-meridian · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/io-github-ajc3xc-meridian