Facio Blog

Practical notes on human-reviewed AI agents.

Payload-powered product notes, security writing, HITL patterns, and operational guidance from the Facio runtime: long sessions, Placet approvals, audit trails, memory, providers, channels, tools, and Docker-first operations.

Showing 26-30 of 236 articles.

Security

Tamper-Evident Audit Logs for AI Agents: The Cryptographic Property That Closes the Self-Attestation Gap

Jul 18, 2026Security

Tamper-Evident Audit Logs for AI Agents: The Cryptographic Property That Closes the Self-Attestation Gap

Tamper-evident audit logs close the self-attestation gap through cryptographic integrity — hash chains, Merkle tree aggregation, external timestamping, WORM storage. The property is the regulatory floor for SEC Rule 17a-4, FDA 21 CFR Part 11, EU AI Act Article 12, and GDPR Article 30. Application-controlled logs are not evidence.

Human-in-the-loop

HITL and the Reciprocity Problem: Why Reviewer Decisions Bias Toward the Customer Even When Policy Suggests Otherwise

Jul 18, 2026Human-in-the-loop

HITL and the Reciprocity Problem: Why Reviewer Decisions Bias Toward the Customer Even When Policy Suggests Otherwise

Reviewers show customers mercy. The policy says reject, the reviewer approves with a note. The policy says escalate, the reviewer reassures. Reviewers don't apply policy neutrally — they apply policy with an unconscious tilt toward the customer's side. The reciprocity problem is the most pervasive reviewer bias in HITL, and the most invisible. Here is how it manifests, why it matters, and how to design for it.

Engineering

MCP Spotlight: Notion MCP Server — The Official Knowledge-Base Bridge With Markdown-Native Retrieval, Two-Tool Minimalism, and the Workspace-Context Default for Agents

Jul 17, 2026Engineering

MCP Spotlight: Notion MCP Server — The Official Knowledge-Base Bridge With Markdown-Native Retrieval, Two-Tool Minimalism, and the Workspace-Context Default for Agents

The official Notion MCP Server by Notion — 2 tools in the minimal profile (notion-search, notion-fetch), Markdown-native retrieval (12x token savings vs raw JSON), OAuth 2.0 with principle-of-least-privilege scopes, full CRUD available in the standard profile. MIT-licensed. The knowledge-base default for AI agents in 2026.

Product

Facio's Idempotency Discipline: How AI Agents Avoid Double-Charging Customers When Retries Happen

Jul 17, 2026Product

Facio's Idempotency Discipline: How AI Agents Avoid Double-Charging Customers When Retries Happen

AI agents fail and retry. The model returns 500, the agent retries the tool call. The network drops mid-flight, the agent retries. The tool returns a timeout but the operation actually succeeded, the agent retries. Without idempotency, retries cause duplicate side effects: double-charged customers, duplicate emails, duplicate records, double-deployed code. Facio's idempotency discipline gives every side-effecting operation a unique key, makes operations safe to retry, and detects duplicate executions before they cause damage.

Security

MCP Server Authentication in 2026: Why OAuth 2.1 with PKCE and Token Exchange Is Now the Only Compliant Pattern

Jul 17, 2026Security

MCP Server Authentication in 2026: Why OAuth 2.1 with PKCE and Token Exchange Is Now the Only Compliant Pattern

The MCP authorization spec mandates OAuth 2.1 with PKCE, RFC 9728 Protected Resource Metadata, RFC 8707 Resource Indicators, and RFC 8693 Token Exchange for zero-touch delegation. Token passthrough is the most dangerous anti-pattern. The compliant stack is the only path to production MCP servers in 2026.