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Head to head · Agent harness · October 2026 research run

Devin vs Pi

Pi scores 68.4 (B) on agent readiness against Devin's 55.7 (C), and leads in 5 of 7 scored categories. Devin leads on security & auth and transparency & trust. Both do agent harness.

DevinCognition AI, Inc. · Agent harness C55.7/100#447 of 629 PiEarendil · Agent harness B68.4/100#170 of 629

Which one, for what

Devin C

Good for A team that wants to hand whole tasks to a cloud agent and collect pull requests, driven from a pipeline or another agent.

Ahead on

  • Security & auth, 72 against 61
  • Transparency & trust, 69 against 64

Also in its favour

  • A hosted endpoint, with nothing to install
  • No incidents deducted, where Pi loses 4 points for them

Watch for

www.devinstatus.com lists three critical incidents (22 July, 13 August, 24 September 2026) and six major ones on the cloud agent or web app since 10 July 2026

Pi B

Good for Developers and pipelines that want a small, scriptable coding agent they can extend in TypeScript and drive over JSONL or RPC, inside their own container.

Ahead on

  • Reliability, 75 against 30
  • Agent ergonomics, 76 against 62
  • Payments & pricing, 60 against 20
  • Maintenance & community, 87 against 63

Also in its favour

  • No key needed to call it
  • Free to start without a card
  • Open source

Watch for

No permission system or sandbox. Tool calls run with the user's rights and without an approval prompt

Score by category

CategoryWeight this runDevinPiEdge
Reliability16%203075Pi +45
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28084Pi +4
Agent ergonomics13%16.26276Pi +14
Security & auth14%17.57261Devin +11
Payments & pricing10%12.52060Pi +40
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.86387Pi +24
Transparency & trust7%8.86964Devin +5
Negative events≤150-4
Total55.7 · C68.4 · B

Facts side by side

FactDevinPi
KindAgent harnessAgent harness
VendorCognition AI, Inc.Earendil
Hosted endpointhttps://mcp.devin.ai/mcpno (local only)
TransportsHTTP
AuthAPI keyNone
PricingFreemiumFree
x402nono
LicenceProprietary service under Cognition's Platform Terms of ServiceMIT
Tools exposed13none
Read-only variant documentedyesno
llms.txtyesno
Last release2026-10-072026-10-07
Terms last updated2026-06-30no document linked
Privacy policy last updated2026-03-09no document linked
Customer content may train modelsyes, with an opt-out
Terms restrict automated accessnot found in the text
Terms restrict benchmarkingyes
Terms or service can change without noticenot found in the text
Arbitration or class-action waiveryes
Popularitynone113k stars, 5.2M npm/wk

Verdicts

Devin

The v3 API is well specified, with a public OpenAPI 3.1 file covering 239 operations, problem+json errors, cursor pagination and service-user keys tied to roles. The status page records three critical and several major incidents on the cloud agent between 22 July and 24 September 2026, and no rate limit figures or retry guidance were found in the reviewed documentation.

Pi

Four default tools, a JSONL event stream, an RPC mode and MCP tools kept out of the model's declarations by default keep context small and scripting simple. Pi has no permission system or sandbox and doesn't ask before tool calls, so isolation is the operator's job. Version 1.0.0 is dated 1 October 2026.

Before you call either

Devin

  1. Use a cog_ service-user key with the Member role. Legacy apk_ keys fail against v3 and the MCP server with 401 or 403
  2. Set max_acu_limit on every session you create. Usage is metered by the work done and has no published unit rate
  3. Session creation is not idempotent in v3. After a timeout, list sessions by tag before creating again
  4. Enterprise keys and personal access tokens must send X-Org-Id to the MCP server. Organisation-scoped keys resolve it automatically
  5. Create scheduled work as an automation. POST to the schedules endpoint returns 403 for migrated organisations since 24 September 2026

Pi

  1. Run Pi inside a container or VM for unattended work. It has no sandbox and doesn't ask before running shell commands
  2. Use pi --mode json and wait for agent_settled. A failed response doesn't set a nonzero exit code in JSON mode
  3. Split the JSONL stream on LF only. Node's readline also splits on U+2028 and U+2029, which are valid inside JSON strings
  4. Pass --no-approve or --approve in scripts to make the project trust decision explicit
  5. Set PI_TELEMETRY=0 and PI_SKIP_VERSION_CHECK=1, or PI_OFFLINE=1, to stop the default requests to pi.dev

Questions

Which is better for AI agents, Devin or Pi?

Pi scores 68.4 (B) on agent readiness against Devin's 55.7 (C), and leads in 5 of 7 scored categories. Devin leads on security & auth and transparency & trust.

Are Devin and Pi open source?

No open-source release is listed for Devin. Pi is open source (MIT).

Other comparisons with Devin or Pi

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