IETF · 30 July 2026
draft-ietf-oauth-transaction-tokens-11
A. Tulshibagwale, G. Fletcher, P. Kasselman
An agent that orchestrates internal tools should pass a transaction token so every microservice sees the original user and the original purpose, not just the agent's workload identity.
At a glance
Actors
01
Inside a trust domain, a user or external request fans out across many workloads. Each hop needs immutable user identity, workload identity, and authorization context that does not silently widen. An agent that orchestrates internal tools should pass a transaction token so every microservice sees the original user and the original purpose, not just the agent's workload identity.
Complements WIMSE (who is calling) rather than replacing it. draft-ietf-oauth-transaction-tokens-11, 30 July 2026. Individual draft-araut-oauth-transaction-tokens-for-agents profiles this for agents.
02
The Transaction Token Service (TTS) is trusted inside the domain. External callers never present a Txn-Token as their only credential. Downstream workloads may replace replaceable context (rctx) but must not mutate tctx immutables. Crossing a domain boundary is identity chaining, not a longer Txn-Token.
03
An entry workload authenticates, then requests a Txn-Token from the TTS using token-exchange-shaped parameters (purpose, request_details, request_context). The token is a short-lived signed JWT, typically carried in a Txn-Token header — not Authorization, so Authorization stays available for WIT/WPT or DPoP. Claims include purp, tctx (immutable), rctx (replaceable). WPT can bind tth/oth to the txn token.
04
Flow 1
External request authenticated (OAuth user token, mTLS, …).
Entry workload requests a Txn-Token from the TTS with purpose and context.
Downstream calls carry Txn-Token plus workload authn (WIT+WPT or mTLS).
Each hop verifies both. tctx stays immutable. Workloads may replace the token per the draft's rules but must not widen authority.
05
Carries identity and authorization context through a call chain. Complements WIMSE workload authn. Not a user-facing grant. Not a substitute for audience-restricted OAuth at the domain edge.
06
Issuance often uses exchange parameters at the TTS.
Workload identity + txn context is the internal pair.
WPT binds hashes of other tokens (tth) so they cannot be swapped.
AIMS recommends Txn-Tokens for internal agent call chains.
draft-liu-oauth-a2a-profile discusses Txn-Tokens on A2A call chains — a usage idea, not A2A v1.0 itself.
07
If tctx can be edited, you no longer have a transaction token. Enforcement is the whole value.
They are context for a trusted domain, not a grant to a stranger's API.
08
draft-ietf-oauth-transaction-tokens-11, 30 July 2026, expires 31 January 2027, OAuth WG, intended standards track. Milestone toward IESG in December 2026 on the WG list. https://datatracker.ietf.org/doc/draft-ietf-oauth-transaction-tokens/. Implement inside a domain you control; expect claim-name stability to be good but not RFC-frozen.
WG Last Call / waiting for write-up as of late July 2026; OAuth WG milestone to submit to IESG in December 2026. Individual draft draft-araut-oauth-transaction-tokens-for-agents profiles this for agents. draft-liu-oauth-a2a-profile discusses Txn-Tokens on A2A call chains.