Stella says done. TookEffect proves it.

Oxagen governs context. Stella acts. TookEffect independently checks the real external system before anyone has to trust the agent's success message.

Oxagen handoff: illustrativeGitHub read-back: liveReceipt verification: liveStella MCP: checking…

01REQUESTED

OxagenGoverned context + authority

02CLAIMED

Stella / agent“The requested change was merged.”

03CHECKED

TookEffectReads GitHub itself

04PROVED

Verified resultVerdict + signed Receipt

Live proof

A success message is not proof.

This demo deliberately starts with an agent claiming success. TookEffect checks authoritative GitHub state instead of trusting that message.

Handoff ExampleProvider state Live

01 · Governed context

EffectGitHub pull request merge

ResourceAuthorized demo change

ExpectedMerged

ProvenanceWorkspace-scoped context

02 · Stella / agent claim

“The requested change was merged.”

The executor says it is done. TookEffect treats that as a claim to verify — never as evidence.

Checking the server-side verification boundary.

Verified result

—

CheckedReal GitHub state

ControlOBSERVE_ONLY

Provider mutationNo

View proof details

—

Real Stella integration

The verifier is already an MCP tool.

This is not a mock integration. Stella can connect to the live TookEffect Streamable HTTP endpoint, discover the read-only verifier, call it, and receive the same provider-backed verdict and Receipt evidence shown above.

MCP server checking…

Connect from Stella

Add this server to .stella/mcp.toml. The demo endpoint is public, target-bound and read-only, so no provider credential or TookEffect credential is placed in Stella.

[servers.tookeffect]
transport = "http"
url = "https://oxagen.tookeffect.com/mcp"
candidate_safe = true

Tool visible inside Stellamcp__tookeffect__verify_github_pull_request_merge

Stella's project trust boundary still applies: export STELLA_TRUST_PROJECT=1 for a repo whose MCP configuration you intentionally trust.

The boundary stays narrow

Oxagen does not need to hand TookEffect its internal graph. Stella sends the claim and, optionally, a provenance reference. TookEffect chooses no target from those values: the approved demo target is bound server-side.

Oxagen supplies governed contextCONTEXT

Stella performs the actionACT

Stella calls TookEffect MCPVERIFY

TookEffect reads provider stateCHECK

Verdict + signed Receipt returnPROVE

Production integration would add tenant authentication and per-target authorization. This POC intentionally exposes only one fixed, read-only demo verifier.