# Season 3 — October 2026 (Autumn / Halloween Edition)

Canonical Web URL: https://adventofagents.com/2026/10/

- **Day 01: [Foundation 101: Five Phases of Agent Development Lifecycle](https://adventofagents.com/2026/10/01?utm_source=adventofagents&utm_medium=markdown&utm_campaign=adventofagents_s3_2026&utm_content=day01)** ([.md](https://adventofagents.com/2026/10/01.md?utm_source=adventofagents&utm_medium=markdown&utm_campaign=adventofagents_s3_2026&utm_content=day01)) — Map the five phases every agent moves through, from Scope to Optimize, and walk one agent around the loop in about five minutes.
- **Day 02: [Agent Security: Implementing SAIF Guardrails](https://adventofagents.com/2026/10/02?utm_source=adventofagents&utm_medium=markdown&utm_campaign=adventofagents_s3_2026&utm_content=day02)** ([.md](https://adventofagents.com/2026/10/02.md?utm_source=adventofagents&utm_medium=markdown&utm_campaign=adventofagents_s3_2026&utm_content=day02)) — Secure agent workflows against rogue actions or data disclosure using SAIF threat modeling.
- **Day 03: [Architecting Secure Multi-Agent Systems](https://adventofagents.com/2026/10/03?utm_source=adventofagents&utm_medium=markdown&utm_campaign=adventofagents_s3_2026&utm_content=day03)** ([.md](https://adventofagents.com/2026/10/03.md?utm_source=adventofagents&utm_medium=markdown&utm_campaign=adventofagents_s3_2026&utm_content=day03)) — Move from single-agent prototypes to hardened, production multi-agent architectures on Google Cloud using Gemini Enterprise
- **Day 04: [Governance Maturity Model: Progressive Trust for Agents](https://adventofagents.com/2026/10/04?utm_source=adventofagents&utm_medium=markdown&utm_campaign=adventofagents_s3_2026&utm_content=day04)** ([.md](https://adventofagents.com/2026/10/04.md?utm_source=adventofagents&utm_medium=markdown&utm_campaign=adventofagents_s3_2026&utm_content=day04)) — Score your agent estate on five governance layers, from Foundation to Continuous Alignment, and turn the result into a staged 90-day roadmap with a 15-question Python self-assessment.
- **Day 05: [Agent Identity: One SPIFFE ID Per Agent](https://adventofagents.com/2026/10/05?utm_source=adventofagents&utm_medium=markdown&utm_campaign=adventofagents_s3_2026&utm_content=day05)** ([.md](https://adventofagents.com/2026/10/05.md?utm_source=adventofagents&utm_medium=markdown&utm_campaign=adventofagents_s3_2026&utm_content=day05)) — Deploy an agent with its own cryptographic SPIFFE identity, grant permissions to the identity and verify it.
- **Day 06: [Token Delegation: Agent acts on-behalf-of the user](https://adventofagents.com/2026/10/06?utm_source=adventofagents&utm_medium=markdown&utm_campaign=adventofagents_s3_2026&utm_content=day06)** ([.md](https://adventofagents.com/2026/10/06.md?utm_source=adventofagents&utm_medium=markdown&utm_campaign=adventofagents_s3_2026&utm_content=day06)) — Give your agent access to external tools, APIs, or services as the signed-in user, so it only sees the records that user is allowed to see.