Three arrows, not one.

Day 107 - 2027-01-12 PT target - Instagram

Video caption

Three arrows, not one.

That is the product seam working.

Substrate enforces without speaking job protocol.

Hang the diagram in review.

Narration uses Eric's authorized AI voice clone.

#EricFieldNotes

Full written post / accessibility read

Draw a product arrow into a job API, a harness arrow into tools, and a substrate box under the harness. Three arrows. If you redraw them as one lightning bolt labeled protocol, you lost the seams.

Show a cancel button on the product side that does not list MCP tool names. If cancel requires knowing every tool, the job seam leaked into the tools plane.

The substrate box can enforce network none and secrets proxy without implementing cancel semantics. That separation is what makes composition safe to review.

Keep that three arrow diagram in architecture review. Companion media can carry it. The point is seams you can point at.

Narration uses Eric's authorized AI voice clone.

#EricFieldNotes

Four-beat scene transcript

1. Three arrows, not one.

Draw a product arrow into a job API, a harness arrow into tools, and a substrate box under the harness. Three arrows. If you redraw them as one lightning bolt labeled protocol, you lost the seams.

Visual: Job down, tools across, substrate under.

2. Cancel without tool names.

Show a cancel button on the product side that does not list MCP tool names. If cancel requires knowing every tool, the job seam leaked into the tools plane.

Visual: That is the product seam working.

3. Kernel without UHP.

The substrate box can enforce network none and secrets proxy without implementing cancel semantics. That separation is what makes composition safe to review.

Visual: Substrate enforces without speaking job protocol.

4. Hang the diagram in review.

Keep that three arrow diagram in architecture review. Companion media can carry it. The point is seams you can point at.

Visual: Composition is a picture, not a slogan.