Agent Architecture / Foundation

Pi is INCREDIBLE - Building a Custom Coding Agent Live

In this live stream Cole Medin explores Pi, a deliberately minimal coding agent you build on top of, testing its many model providers and extensions, integrating it with his open-source Archon harness, and building a custom Archon-dispatch extension while running Kimmy K2.6 to show where cheaper models succeed and where they hit their limits.

Cole MedinWatchTranscript found

Quick learning frame

Read this before watching.

A model becomes useful when it is wrapped in a harness: tools, state, permissions, memory, routing, and verification.

New playlist item from Cole Medin; queued for transcript-backed review, topic mapping, and a practical learning artifact.

Skill you build: The ability to mold a minimal coding agent to your own workflow through custom extensions and harness engineering, and to route cheaper open-source models to the parts of a workflow where they hold up while reserving a powerful model for where it's needed.

Watch for the shift from claim to mechanism. The learning value is the point where the transcript reveals a repeatable action, tool boundary, context move, review habit, or artifact.

Concept diagram

Where this video fits.

01Intent
02Model
03Harness
04Tools
05Verifier
06Artifact

Deep lesson

Turn this video into working knowledge.

16,380 cleaned transcript words reviewed across 4,654 timed caption segments.

Thesis

Pi is INCREDIBLE - Building a Custom Coding Agent Live teaches a practical agent architecture move: In this live stream Cole Medin explores Pi, a deliberately minimal coding agent you build on top of, testing its many model providers and extensions, integrating it with his open-source Archon harness, and building a custom Archon-dispatch extension while running Kimmy K2.6 to show where cheaper models succeed and where they hit their limits.

The goal is not to remember the video. The goal is to extract the operating principle, tie it to timestamped evidence, test how far the claim transfers, and make something reusable.

0:14

Adapt Pi to you

“other coding agents right now. And so, the idea behind Pi is it is a minimal coding agent. It's made to be a coding agent that you build on top of instead of taking a really massive bloated...”

Pi is a minimal coding agent designed so you build on top of it and adapt it to your workflow instead of retrofitting a bloated tool; it supports many providers out of the box (OpenRouter, Kimmy, Miniax, Qwen, Codex, Copilot), though using an Anthropic Claude Pro/Max subscription with Pi is against Anthropic's terms of service and not recommended. Open Pi's provider list and pick one non-Anthropic model (via OpenRouter or a subscription) to configure, noting why you'd choose it over the default.

26:40

Extensions need pointing

“factory. Curious how pi could help. So the the reason pi could be really helpful for the dark factory is because I have a very specific workflow for the way that I have the coding agent evolve the...”

Pi ships minimal and installs only the extensions you need (sub-agents and MCP aren't native), but Pi didn't automatically understand which installed extensions it had, getting confused until told explicitly to use the questionnaire extension, suggesting you may need global rules that specify when to invoke a given extension. Install one Pi extension and test whether the agent uses it from a natural prompt, then add a global-rule line telling it exactly when to trigger that extension.

87:25

Limits of cheap models

“extension so that the output of like the the last output from the workflow needs to go directly back into the the PI session I thought that's what you already had set up, but obviously not. It's very...”

Building a custom Archon-dispatch extension with Kimmy K2.6, the model got the extension almost working but repeatedly failed to inject the workflow's final output back into the Pi session; Cole notes he'd bet a good amount he'd have avoided this with Opus 4.7, illustrating using a cheap model to start or research and implement, then a powerful model to fix the final bug. Take a small extension or script, draft it with a cheaper model, and note exactly where it breaks so you can hand just that final fix to a stronger model.

01

Intent

Start with this video's job: In this live stream Cole Medin explores Pi, a deliberately minimal coding agent you build on top of, testing its many model providers and extensions, integrating it with his open-source Archon harness, and building a custom Archon-dispatch extension while running Kimmy K2.6 to show where cheaper models succeed and where they hit their limits. Treat "Intent" as the outcome you are trying to make visible, not a topic label. Anchor it to 0:14, where the video says: “other coding agents right now. And so, the idea behind Pi is it is a minimal coding agent. It's made to be a coding agent that you build on top of instead of taking a really massive bloated...”

02

Model

Use "Model" to locate the part of the agent architecture workflow the video is demonstrating. Ask what changes in your real setup if this claim is true. Anchor it to 26:40, where the video says: “factory. Curious how pi could help. So the the reason pi could be really helpful for the dark factory is because I have a very specific workflow for the way that I have the coding agent evolve the...”

03

Harness

Turn "Harness" into the reusable artifact for this lesson: A one-page agent harness map with tool boundaries and proof signals. This is where watching becomes something you can inspect and reuse.

04

Tools

Use "Tools" as the application surface. Decide whether the idea touches a browser flow, a local file, a model choice, a source document, a UI, or a review step.

05

Verifier

Use "Verifier" to prove the lesson. The evidence should connect back to the video title, transcript anchors, and a concrete output, not a generic best-practice claim.

06

Artifact

Use "Artifact" to carry the idea forward: save the prompt, checklist, diagram, or operating rule that would make the next agent run better.

Example

Source-backed work packet

Convert the video into a scoped task that includes the transcript claim, target workflow, acceptance criteria, and proof. The output should be a one-page agent harness map with tool boundaries and proof signals..

Example

Claim vs. demo brief

Separate what the speaker claims, what the demo actually proves, and what still needs outside verification before you adopt the workflow.

Example

Teach-back module

Transform the lesson into a definition, a mechanism diagram, one misconception, one practice exercise, and a check-for-understanding question.

Do not learn it wrong
  • Treating the title as the lesson without checking what the transcript actually says.
  • Letting the prompt drift into generic advice that could apply to any video in the playlist.
  • Copying the tool setup without identifying the operating principle that transfers to your own stack.
  • Skipping the artifact, which means the learning never becomes operational or inspectable.

Transcript-derived moments

Use timestamps to study the actual video.

Quality check

Do not count this as learned until these are true.

01

State the transcript-backed claim in your own words: In this live stream Cole Medin explores Pi, a deliberately minimal coding agent you build on top of, testing its many model providers and extensions, integrating it with his open-source Archon harness, and building a custom Archon-dispatch extension while running Kimmy K2.6 to show where cheaper models succeed and where they hit their limits.

02

Explain the practical stakes without hype: New playlist item from Cole Medin; queued for transcript-backed review, topic mapping, and a practical learning artifact.

03

Map the idea onto the Intent -> Model -> Harness -> Tools -> Verifier -> Artifact sequence and name the weakest link.

04

Produce the artifact and include the evidence that proves it: A one-page agent harness map with tool boundaries and proof signals.

Put it into practice

Give this grounded prompt to Codex or Claude after watching.

You are helping me turn one specific YouTube video into real, durable learning.

Source video:
- Title: Pi is INCREDIBLE - Building a Custom Coding Agent Live
- URL: https://www.youtube.com/watch?v=lK9o5Wu2upU
- Topic: Agent Architecture
- My current learning frame: Install Pi, wire it to one non-Anthropic model, build a small custom extension with a cheaper model, and observe where it hits its limits so you can hand only the final fix to a more powerful model.
- Why this matters: New playlist item from Cole Medin; queued for transcript-backed review, topic mapping, and a practical learning artifact.

Transcript anchors from this exact video:
- 0:14 / Evidence 1: "other coding agents right now. And so, the idea behind Pi is it is a minimal coding agent. It's made to be a coding agent that you build on top of instead of taking a really massive bloated..."
- 7:00 / Evidence 2: "great because it really is this minimal agent that allows us to use any model we could possibly dream of. Like we can use Kimmy K 2.6 for example, like I'll use in the stream today. But then..."
- 26:40 / Evidence 3: "factory. Curious how pi could help. So the the reason pi could be really helpful for the dark factory is because I have a very specific workflow for the way that I have the coding agent evolve the..."
- 28:12 / Evidence 4: "Okay. Um, Jcode. Sure. So I they Okay. So you can see that Pi is the second best, but apparently J-code is better with local embeddings off. I don't care that much about speed. Like here, here's the..."
- 49:01 / Evidence 5: "and rules and things like that, but it's like fundamentally even the coding agent itself, how it operates with the core loop, the core while loop of the agent. Like even that you can change. You can tweak..."
- 71:51 / Evidence 6: "really neat. The Codeex app specifically how you can manage your different projects and parallel agents and like the updates from there. It's kind of like the agent view that Claude Code released where you can see all..."
- 87:25 / Evidence 7: "extension so that the output of like the the last output from the workflow needs to go directly back into the the PI session I thought that's what you already had set up, but obviously not. It's very..."

Your task:
1. Use the transcript anchors above as the primary source packet. If you add outside context, label it clearly as outside context and keep it secondary.
2. Create a source-check table with columns: timestamp, claim, what the demo proves, confidence, and what still needs verification.
3. Extract the actual teachable claims from the video. Do not invent claims that are not supported by the title, lesson frame, or transcript anchors.
4. Build a reusable learning artifact: A one-page agent harness map with tool boundaries and proof signals.
5. Include:
   - a plain-English definition of the core idea
   - a diagram or structured model using this sequence: Intent -> Model -> Harness -> Tools -> Verifier -> Artifact
   - 3 concrete examples that apply the video idea to real agentic work
   - 2 failure modes the video helps prevent
   - a checklist I can use the next time I run Codex or Claude
   - one practical exercise with a clear done signal
6. Add a "learning transfer" section: what changes in my workflow tomorrow if I actually learned this?
7. Add a "source check" section that cites which transcript anchor supports each major takeaway.

Quality bar:
- Make this specific to "Pi is INCREDIBLE - Building a Custom Coding Agent Live", not a generic Agent Architecture essay.
- Prefer operational examples, failure modes, and reusable artifacts over broad definitions.
- Call out uncertainty instead of smoothing over weak evidence.
- If evidence is weak, say what transcript segment or timestamp needs review instead of guessing.
- Finish with a concise artifact I could paste into my learning app.

Misconceptions

What to stop believing.

A better model automatically makes a better agent.

The model matters, but harness design determines whether the system can act safely and repeatably.

More tools always help.

Every tool increases surface area. Strong agents have the right tools with clear permissions.

Memory means saving everything.

Useful memory is compressed, curated, and tied to future decisions.

Practice studio

Learning only counts when you make something.

01

Transcript evidence map

Separate what the video actually says from what you already believe about the topic.

3 source-backed takeaways with timestamps, confidence, and a transfer note.
02

One useful artifact

Apply the video to a real workflow and produce a one-page agent harness map with tool boundaries and proof signals..

A reusable artifact with a done signal and one verification step.
03

Teach-back card

Explain the lesson to someone who has not watched the video yet.

A 90-second explanation, one diagram, one example, and one misconception to avoid.

Recall check

Answer first, then reveal — without rewatching.

What is the design philosophy of Pi, and which model source is off-limits?

What issue did Cole hit with Pi's extensions during the stream?

What did building the Archon extension with Kimmy K2.6 reveal about cheap models?

Source shelf

Use the video as a doorway, then verify with primary sources.

DocsOpenAI Agents SDK: agents

Read this for the basic object model: instructions, tools, handoffs, guardrails, and structured outputs.

openai.github.io/openai-agents-python/agents/
DocsOpenAI Agents SDK: tracing

Use this to understand why observability is part of agent architecture.

openai.github.io/openai-agents-python/tracing/
DocsOpenAI Agents SDK: guardrails

Good follow-up for thinking about boundaries, tripwires, and tool-level checks.

openai.github.io/openai-agents-python/guardrails/
DocsOpenAI Agents SDK: handoffs

Explains delegation between specialized agents and what context gets forwarded.

openai.github.io/openai-agents-python/handoffs/
ReadingModel Context Protocol

Useful for understanding how external tools and context servers become part of the agent environment.

modelcontextprotocol.io/introduction
PodcastLatent Space: The AI Engineer Podcast

Best ongoing podcast lane for agent tooling, AI engineering, codegen, infra, and model shifts.

www.latent.space/podcast
PodcastPractical AI podcast archive

Older but still useful practical conversations on agents, AI engineering, and production concerns.

changelog.com/practicalai/